Consumer purchase behaviour and date labelling of food: Selection behaviour as a contributor to food waste

An investigation of consumers’ tendency to select food items with a longer expiration date in retail stores

Bo van Geel 290878 (ANR)

Master Thesis

MSc Marketing Analytics July 2018

CentERdata

Submission date: July 31st, 2018 Master of Marketing Analytics (MSc MA) Tilburg School of Economics and Management Tilburg University Master’s Thesis supervisors: dr. M. Elsen (CentERdata & Tilburg University) dr. A.M.M. Bosmans (Co-reader Tilburg University)

Management Summary

A substantial amount of food produced for human consumption is wasted nowadays, which entails

negative economic, environmental, and ethical consequences (Gustavsson, Cederberg, & Sonesson,

2011). It is presumed in the literature that consumers’ tendency to select food items with a longer or the

longest expiration date in retail stores contributes to food waste. This particular consumer purchase

behaviour has been referred to as date labelling selection behaviour. In two experimental studies, it is

investigated (I) how big the proportion of consumers is that engage in this selection behaviour, (II)

which consumer motives underlie this behaviour, (III) when consumers are more/less likely to engage

in this behaviour, and (IV) what the retailer could do about it. Based on the empirical results it can be

concluded, with respect to limited shelf life food, that almost two-thirds engaged in date labelling

selection behaviour. This finding is in line with the existing literature suggesting that consumer’s date

labelling selection behaviour is omnipresent and therefore problematic. Consumer’s primary reason for

engaging in selection behaviour was that this would give them more time to consume the food and

therefore more flexibility. Consumers turned out to be less inclined to engage in date labelling selection

behaviour when they had the intention to consume the food on the same day as the day on which the

food was purchased, when they are aged fifteen to twenty-four, are higher educated, have a higher net

monthly household income, and have bigger households. Unfortunately, it can be concluded that the

first attempt at finding an effective solution against date labelling selection behaviour has failed. The

proposed retailer interventions – messages that challenge the underlying consumer motives for selection

behaviour, printed on sticky labels attached to food items in front of the shelf – turned out not to have

the desired negative effect on date labelling selection behaviour. Further research is necessary in order

to find and test successful solutions against consumer’s selection behaviour.

Keywords: Date labels, expiration date, retailer-generated food waste, consumer motives, behavioural

interventions, date labelling selection behaviour

Preface

In February 2018 I started as a graduate intern at CentERdata to write my Master thesis. This Master

thesis represents the final part of my Master Marketing Analytics at Tilburg University. The Master

Marketing Analytics suited my interests perfectly and I studied all its facets with great pleasure. The

same goes for my Master thesis: I enjoyed studying and investigating consumer’s purchase behaviour

in food retail stores. I have always been interested in the way consumers act, and it felt satisfactory and

rewarding to connect this to the social issue of food waste. If you do something you like, it often will

not feel like work.

Nonetheless, while writing my thesis it sometimes felt that there were not enough hours in the day. This

thesis would not have been possible in the way as it is now without Millie Elsen. Millie’s expertise,

feedback and guidance were of great value, and I hereby would like to thank her for that. Further thanks

go out to everyone else who helped make this thesis possible. I would like to thank CentERdata for the

internship opportunity, the pleasant working atmosphere, and the facilities to work with. It was a

pleasure to be part of CentERdata. Furthermore, I would like to thank my family and friends for their

support and encouragement. I hope this Master thesis might be helpful to some extent in the battle

against food waste.

I am excited to see what the future has in store for me,

Bo van Geel

Tilburg, July 2018

Table of Contents

Management Summary ....................................................................................................................................

Preface ..............................................................................................................................................................

Table of Contents .............................................................................................................................................

Introduction and Problem Indication ............................................................................................................ 1

1.1 – Introduction and Problem Background ................................................................................................. 1

1.2 – Problem Indication and Statement ........................................................................................................ 3

1.3 – Conceptual Model ............................................................................................................................... 6

1.4 – Thesis Structure ................................................................................................................................... 7

Study 1 ............................................................................................................................................................ 9

2.1 – Purpose ............................................................................................................................................... 9

2.2 – Theory and Predictions ........................................................................................................................ 9

2.3 – Methodology ..................................................................................................................................... 13

2.3.1 – Experimental Design and Participants ........................................................................................ 13

2.3.2 – Materials.................................................................................................................................... 14

2.3.3 – Procedure and Measures............................................................................................................. 15

2.4 – Results .............................................................................................................................................. 17

2.4.1 – Main Analysis ............................................................................................................................ 17

2.4.2 – Follow-up Analysis: Consumer Profiling .................................................................................... 21

2.5 – Preliminary Conclusion ..................................................................................................................... 23

Study 2 .......................................................................................................................................................... 25

3.1 – Purpose ............................................................................................................................................. 25

3.2 – Theory and Predictions ...................................................................................................................... 25

3.3 – Methodology ..................................................................................................................................... 27

3.3.1 – Experimental Design and Participants ........................................................................................ 27

3.3.2 – Manipulation of the Type of Message ......................................................................................... 28

3.3.3 – Materials.................................................................................................................................... 28

3.3.4 – Procedure and Measures............................................................................................................. 30

3.4 – Results .............................................................................................................................................. 31

3.4.1 – Main Analysis ............................................................................................................................ 31

3.4.2 – Follow-up Analysis: Moderators of the type of message effect .................................................... 32

3.5 – Preliminary Conclusion ..................................................................................................................... 37

Conclusions and Recommendations ............................................................................................................. 39

4.1 – General conclusion and discussion ..................................................................................................... 39

4.2 – Recommendations ............................................................................................................................. 41

4.3 – Limitations and suggestions for further research ................................................................................. 41

References .................................................................................................................................................... 43

Appendix 1 – Questionnaire Study 1 ........................................................................................................... 47

Appendix 2 – Results Study 1 ....................................................................................................................... 49

Appendix 3 – Instruction Study 2 ................................................................................................................ 51

Appendix 4 – Post-Experiment Questionnaire Study 2 ............................................................................... 53

Appendix 5 – Results Study 2 ....................................................................................................................... 55

Appendix 6A – Follow-up Analysis Study 2 with ‘time’ .............................................................................. 59

Appendix 6B – Follow-up Analysis Study 2 with ‘intention to avoid food waste’ ....................................... 61

Appendix 6C – Follow-up Analysis Study 2 with ‘noticing the message labels’ .......................................... 65

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Introduction and Problem Indication

1.1 – Introduction and Problem Background

In this era of prosperity, consumerism and abundance of choice in Western societies, food waste has

become a noticeable part of everyday life. In both Europe and the United States, the amount of available

food per capita in retail stores, supermarkets and restaurants has increased rapidly during the last

decades (Gustavsson, Cederberg, & Sonesson, 2011). In addition, contemporary consumers can simply

afford to waste food. The abundance of food, together with consumer attitudes, leads to substantial food

waste and disposal nowadays (Gustavsson et al., 2011).

Although almost impossible to obtain precise figures, United Nations’ Food and Agriculture

Organization (2013) states that approximately one-third of produced food for human consumption is

lost or wasted globally nowadays, which results in 1.3 billion ton of disposed food per year. The amount

of food losses and waste per capita are the highest in North America and Oceania (almost 300 kg/year),

followed by Europe (280 kg/year) according to Figure 1 (Gustavsson et al., 2011, p. 5).

Food is lost and wasted throughout the entire food supply chain; from agricultural production to

postharvest treatment, to processing and distribution to catering and retailers, and eventually at

household consumption (Gustavsson et al., 2011). The food supply chain can best be described as the

connected activities used to produce, process, distribute and consume food (Stenmarck, Jensen,

Quested, & Moates, 2016). Whereas food losses occur primarily at the production, postharvesting and

processing stage of the food supply chain, food waste occurs near the end of the food supply chain at

the caterer, retailer, and consumption stage (Parfitt, Barthel, & Macnaughton, 2010). Food waste can

be described as food fit for human consumption that is nonetheless unconsumed (Parfitt et al., 2010).

Figure 1 - Per capita food losses and waste, at consumption and pre-consumption stages, in different regions. Reprinted from “Global Food Losses and Food waste” by J. Gustavsson, C. Cederberg, U. Sonesson, 2011, Food and Agriculture Organization of the United Nations, 37, p. 5.

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In medium- and high-income countries1, food is to a great extent wasted as opposed to lost (Gustavsson

et al., 2011). There are multiple serious negative consequences of food waste (Graham-Rowe, Jessop,

& Sparks, 2014). Food waste is, to start, obviously a waste of money and good food (Gustavsson et al.,

2011). Since more value in terms of money and resources is added for every step in the food supply

chain, food waste entails a substantial loss of value (Eriksson, 2015). From an ethical perspective, food

waste has a substantial moral impact since a large part of the world’s population is starving and/or

malnourished (Williams, Wikstrom, Otterbring, Lofgren, & Gustafsson, 2012). According to the Food

and Agriculture Organization (2013), the food that is currently wasted in Europe could feed 200 million

people. In addition, food waste increases global food prices and therefore makes food less accessible

for people in underdeveloped countries (Graham-Rowe et al., 2014). Furthermore, food waste is also

harmful to the environment. Eventually, a huge amount of natural resources in food production – such

as land, water and energy - are used for nothing. Greenhouse gas emissions caused by the production

of food that in the end gets wasted, are eventually emissions in vain (Gustavsson et al., 2011; Graham-

Rowe et al., 2014). The volume of food waste should be downsized in order to sustain the world’s

limited natural resources and to ensure enough food for all humans (Williams et al., 2012).

Considering the negative economic, environmental, and ethical consequences of food waste, the

question should be raised and addressed by whom, and on what grounds, so much food intended for

human consumption is wasted nowadays. Food wastage clearly is a complex issue with multiple factors

impacting disposal (Aschemann-Witzel, de Hooge, Amani, Bech-Larsen, & Oostindjer, 2015). It

appears that, in Western societies, both the retail and consumption stage of the food supply chain play

a significant role in the problem of food waste (Aschemann-Witzel et al., 2015). Particularly, the retail

stage appears to be an important pawn as regards the problem of, and in the fight against, food waste.

Food retailers play a considerable role in causing food waste, as well as in offering potential solutions

to lower food waste at the same time given their crucial position at the food supply chain - consumer

interface (Aschemann-Witzel, de Hooge, & Normann, 2016). Food retailers have the tools and power

to exert substantial influence in shaping both the features of food production upstream, as well as the

purchase preferences and behaviour of consumers downstream via e.g. certain marketing tactics

(Cicatiello, Franco, Pancino, Blasi, & Falasconi, 2017).

The share of European food losses and waste attributable to the retail stage is around 5 percent

(European Commission, 2015). In the Netherlands, the retail sector is accountable for approximately 7

percent of total food disposal (Soethoudt, Vollebregt, & van der Burgh, 2016). The Netherlands

currently has around 4300 supermarkets located across the country (Centraal Bureau

Levensmiddelenhandel, 2018). Annually, Dutch supermarkets discard food worth around 400 million

euro (De Vocht, 2018). Food waste recording procedures differ considerably between retailers, and

1 Europe (including Russia), the United States, Australia, New Zealand, China, Japan, and South – Korea (Gustavsson et al., 2011)

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food waste related information is most of the time kept private (Parfitt et al., 2010). Country- and

supermarket-specific case studies best represent the current literature on the quantification of food waste

in the retail sector, combined with an attempt to extrapolate the findings to the bigger picture

(Lebersorger, & Schneider, 2015; Cicatiello, Franco, Pancino, & Blasi, 2016). Based on multiple

studies, (semi-)perishable food with a short to limited shelf life accounts for the highest proportion of

food waste in the retail sector (Parfitt et al., 2010). Among the food product categories analysed, bread,

fresh fruit and vegetables, meat, and dairy products stand out in terms of retailer-generated food waste

(Cicatiello et al., 2017). At the bottom of retailer’s disposal list there is canned, dried and frozen food

all with a long shelf life (Stenmarck, Hanssen, Silvennoinen, Katajajuuri, & Werge, 2011). But what

makes this food wastage? There are multiple routes that cause food waste in retail stores, either relating

to stock management practices as well as to purchasing behaviour of consumers (Cicatiello et al., 2017;

Gustavsson et al., 2011). Part of retailer-generated food waste is caused by a mismatch between supply

and demand due to misjudgment of the retailer, leaving abundant products unsold (Schripsema, van der

Burgh, van der Sluis, & Bos-Brouwers, 2015). Notably, there is always some degree of surplus stock

in supermarkets (Storup, Mattfolk, Voinea, Jakobsen, Bain, Reverte, & Oliveira, 2016). However, the

mismatch between supply and demand has grown relatively smaller over the years due to strongly

improved, data-driven computer-generated mechanisms to predict demand and to keep track of stock

records. In addition, consumer behaviour and preferences in-store are also strong drivers of food waste

at the retail level (Parfitt et al., 2010). For example, perceived suboptimal food by consumers – e.g.

damaged food, food not perfectly shaped, or food with the shortest remaining shelf life – is often left

unsold and wasted in the end in retail stores (Storup et al., 2016). The consumer role with respect to

food waste in retail stores is very decisive, while at the same time susceptible to influences from food

retailers (Aschemann-Witzel et al., 2015). Therefore, the retailer-consumer interface is a valuable field

to focus upon in the battle against food waste (Aschemann-Witzel et al., 2015).

1.2 – Problem Indication and Statement

Date labelling of food products has been practiced for decades, and it is used as a communication tool

to achieve stock rotation at retail while at the same time providing information to consumers (Parfitt et

al., 2010). Date labels on food are either based on product quality (best before date, also known as “ten

minste houdbaar tot datum” in Dutch), or on product safety (use-by date, also known as “te gebruiken

tot datum” in Dutch). Quality date marks represent a date by which the product should be consumed for

ideal or optimal quality; it is a date of minimum durability and after that date the food quality starts to

deteriorate from its peak. Such food products can be consumed after the printed date, it is then

encouraged to use one’s own senses to determine product quality and freshness before simply throwing

it away (Newsome et al., 2014). On the contrary, safety date marks represent an expiry date after which

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the product must be discarded due to health safety reasons. The printed date stands for the endpoint of

food in terms of ‘microbiological load’ rather than consumer taste (Milne, 2012). Despite the good

communicative intentions, the food wastage discussion has pointed to date labelling as one of the

biggest contributors to the unnecessary waste of edible food (Milne, 2012; Newsome et al., 2014).

Approximately 10 percent of total food waste at the caterer, retailer and consumption stage is solely

attributable to date labelling of food (European Commission, 2018). Considering retail stores, studies

have found that the majority of its food waste is ascribable to date labelling (Garrone, Melacini, &

Perego, 2014). Problematic is that food retailers are not allowed to sell food products that have passed

their date mark, so expired food products will inevitably be disposed and removed from the shelves

regardless of their current, actual quality and edibility (Storup et al., 2016). This prohibition to sell

expired food is regulated by law and therefore difficult to counter. Although disposed food is to some

extent donated to local foodbanks, used for animal feed, used for biogas, or used as fertilizer in the form

of compost, the majority of disposed food in supermarkets is actually wasted (Schripsema et al., 2015).

However, food waste as a result of date labelling is not solely attributable to the retailer because they

are not allowed to sell expired food; food waste as a result of date labelling is also ascribable to the

consumer. Date labelling of food influences consumer purchase behaviour in retail stores; it influences

consumer preferences with respect to which food product they want and – more importantly with respect

to food turning into waste – not want to buy. Literature suggests that many consumers regularly look at

and make use of date labels to guide purchase decisions, and it turns out that these decisions often

contribute to (even more) food waste (Lyndhurst, 2011). To elaborate, a ‘first in, first out’ (FIFO)

issuing policy is most often in place as regards retailer’s stock management and product display in-

store. The FIFO principle is regularly used as a shelf-filling system for food products that are subject to

decay (Ferguson, & Ketzenberg, 2006). When stocking and replenishing store shelves based on the

FIFO principle, new food items are added at the rear end of the shelf or at the bottom of a pile. FIFO

issuing has the objective of minimizing the amount of outdated food (Ferguson, & Ketzenberg, 2006).

However, it turns out that food items closest to expire, and thus in front of the shelf or at the top of a

pile, are often ignored by consumers (Gustavsson et al., 2011). Retailers stock food products with

multiple expiration dates which has the implication that food items closest to expire are often ignored

by consumers, with some of these ignored food items turning into waste eventually (Hug, Asnani, Jones,

& Cutright, 2005). It can be argued that date labels influence consumer’s acceptance and desirability of

food items in-store (Newsome et al., 2014). A study conducted by Lyndhurst (2011) shows that 87

percent of participants indicated to refer to date labels while shopping, and 39 percent of participants

indicated to look for the longest date available while shopping. To be more precise, the relationship

between date labelling of food and consumer behaviour during the retailer-consumer interface is

particularly reflected in ‘selection behaviour’, implying that consumers will often opt for the product

on the shelf with the latest expiry date (Soethoudt, Sluis, Waarts, & Tromp, 2013). This ‘selection

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behaviour’ relates to sorting out food items based on the length of their remaining shelf life, and

subsequently buying food items with a longer, or the longest, remaining shelf life. Consumer preference

for younger products often involves reaching for products at the back of a shelf or at the bottom of a

pile (Newsome et al., 2014). This somewhat peculiar behaviour has been referred to as ‘date labelling

selection behaviour’ or ‘sorting dillema’ (Newsome et al., 2014), or ‘datumduiken’ as we named it in

Dutch. The problem with this date labelling selection behaviour of consumers – under the assumption

that a substantial part of consumers engage in this behaviour – is that it causes older food items to

remain on the shelf for a longer period of time, approaching their date mark as each day goed by thereby

becoming (even) less and less attractive (Soethoudt et al., 2013). Eventually, if these older food items

do not get picked, they will most likely turn into waste (Aschemann-Witzel et al., 2015). In other words,

date labelling selection behaviour increases the likelihood of (older) food items becoming outdated and

turning into food waste. It is expected that a lot could be gained from changing this selection behaviour

of consumers since this would mean reducing the amount of retailer-generated food waste together with

its negative environmental, ethical, and economic consequences.

Surprisingly little is known about date labelling selection behaviour. There are several studies which

suggest that consumers’ tendency to select food items with a longer expiration date contributes to food

waste and is therefore problematic (Gustavsson et al., 2011; Newsome et al., 2014; Southoudt et al.,

2013). Furthermore, a small cluster analysis has been conducted by Lyndhurst (2011) on behalf of the

‘Waste and Resources Action Programme’ (WRAP), where participants were clustered based on the

degree of ‘attention paid to date labels’ in-store and at home. This study showed that 39 percent was

‘date driven’ (always looking for the longest date mark in-store and keeping an eye on date labels at

home), 48 percent was ‘date savvy’ (sometimes looking for the longest date mark in-store and keeping

an eye on date labels at home), and 13 percent was ‘date disengaged’ (Lyndhurst, 2011). However, so

far it has not been empirically studied how big the proportion of consumers exactly is that engage in

date labelling selection behaviour, why consumers do so, when consumers are more likely to do so

etcetera. Because of all this, it should first be determined whether date labelling selection behaviour is

really a problem in the first place by examining the share of consumers that actually engage in this

selection behaviour. If only a relatively small part of consumers engage in date labelling selection

behaviour it does not seem to be a real, far-reaching problem. But if it turns out that a substantial part

of consumers engage in this selection behaviour, it might be valuable to understand and to successively

examine why consumers engage in date labelling selection behaviour, when consumers are ‘more’

versus ‘less’ inclined to engage in date labelling selection behaviour, and - most importantly – what can

be subsequently done by retailers to intervene with this selection behaviour. It is often argued that it

lies within the power of retailers to influence the behaviour of their customers (Young, Russel,

Robinson, & Chintakayala, 2018). Based on the aforementioned, the following research questions are

focused on:

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1. To what extent do consumers engage in date labelling selection behaviour? (I.e. How big is the share of consumers that engage in date labelling selection behaviour? Is it really a problem?)

2. Why do consumers engage in date labelling selection behaviour? (I.e. Which consumer motives underlie date labelling selection behaviour?)

3. When are consumers more/less inclined to engage in date labelling selection behaviour? (I.e. In which situations is date labelling selection behaviour ‘more’ versus ‘less’ strong?)

4. What can the retailer do about date labelling selection behaviour? (I.e. What can the retailer do to improve consumer acceptance of food items with the shortest remaining shelf life?)

As a final remark, consumers are more likely to opt for younger food items for some particular product

types than for other product types. The literature suggests that the use of date labels by consumers varies

according to product type (Lyndhurst, 2011). Food can broadly be subdivided into 3 categories (van der

Vossen, & van Dooren, 2016):

- Very fresh, short shelf life food products (e.g. meat and prepacked ready-to-eat meals)

- Limited shelf life food products (e.g. packed meat products and dairy products)

- Long shelf life food products (e.g. soda and confectionery)

According to a study conducted by Lyndhurst (2011), the deliberate use of date labels by consumers

when making purchase decisions primarily occurs with (semi-)perishable food products with a short or

limited shelf life. Participants in Lyndhurst’ study reported paying most attention to date labels on meat

and dairy products (especially yoghurts), whereas paying the least attention to date labels on bread, and

fresh fruit and vegetables during the moment-of-purchase in-store (Lyndhurst, 2011). This research

focuses on food products with a limited shelf life with respect to the problem of date labelling selection

behaviour. This focus decision is guided by the general consensus that date labelling selection behaviour

is not really in operation at food products with a long shelf life, together with the accompanied danger

of focusing on fresh food products with a short shelf life. In almost all instances, fresh, highly perishable

food products with a short shelf life carry a ‘use-by’ date mark denoting product safety. After the expiry

date, such products should be discarded due to health safety reasons and therefore this forms a rather

dangerous product category to focus upon. One wants consumers to handle this product category with

care, and behavioural changes with respect to consumer’s date labelling selection behaviour could

jeopardize this.

1.3 – Conceptual Model

Based on the four research questions (denoted by I, II, III and IV) formulated in the previous section,

the following conceptual model is proposed and used as a guide throughout this research (Figure 2).

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This conceptual model revolves around the assumption that date labelling selection behaviour is

problematic because a substantial part of consumers engage in this selection behaviour. This conceptual

model shows that consumer motives lead to, and are the underlying reason of, date labelling selection

behaviour by consumers. In turn, retailers can impose interventions aimed to weaken or disempower

these consumer motives in an attempt to reduce date labelling selection behaviour. Whether the retailer

interventions are effective, depends on the presence or absence of various situational/contextual factors

which in turn influence consumer motives. The exact content of this conceptual model will be explained

in more detail in next sections in Study 1 and Study 2.

1.4 – Thesis Structure

The structure of this thesis is built around a general framework established by Steg and Vlek (2009)

about encouraging pro-environmental behaviour. One wants consumers to behave pro-environmentally

and to reduce consumer-related food waste in retail stores. Steg and Vlek (2009) propose the following

steps in effectively encouraging and establishing pro-environmental behaviour:

1. Identification of the behaviour to be changed

2. Examination of the main factors underlying this behaviour

3. Design and application of interventions to change behaviour to reduce environmental impact

4. Evaluation of the effects of the behavioural interventions

In addition to this introductory chapter, this thesis will consist of two studies each addressed in separate

chapters, followed by a final, concluding chapter. Study 1, a large-scale online study, will examine the

extent to which consumers engage in date labelling selection behaviour (research question 1) and why

they do so (research question 2). As a follow-up analysis, various consumer types will be profiled. This

first study aims to (inter alia) demonstrate the relevance of this research by investigating the extent to

Retailer Interventions Consumer Motives Date Labelling Selection Behaviour

Figure 2 – Conceptual model

I II IV

III

Situational / Contextual Factors

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which consumers engage in date labelling selection behaviour. Study 2, a small-scale follow-up study,

will test potential retailer interventions in a first step to reduce date labelling selection behaviour

(research question 4). In addition, both studies will examine situations in which consumers could be

more/less inclined to engage in date labelling selection behaviour (research question 3). The final,

concluding chapter will provide a coherent and comprehensive discussion regarding the four research

questions, and it will also address possible limitations and suggestions for further research.

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Study 1

2.1 – Purpose

Primarily, this large-scale online study aims to seek answers to the following research questions:

1. To what extent do consumers engage in date labelling selection behaviour?

2. Why do consumers engage in date labelling selection behaviour?

By examining how big the share of consumers is that engage in date labelling selection behaviour, it

will be determined whether this selection behaviour of consumers is really detrimental or not. Because

of the assumption that consumer’s date labelling selection behaviour ís problematic, it will be

simultaneously examined which consumer motives underlie this selection behaviour together with

which motive is most important for consumers. These insights can in turn be used as valuable input for

the design and application of retailer interventions aimed to reduce consumer’s date labelling selection

behaviour (which will be the topic of the second study). In addition, in this first study it will be attempted

to disempower one of the which we believe to be important consumer motives underlying date labelling

selection behaviour, by trying to turn it into a non-sense argument, to see whether that influences the

extent to which consumers engage in date labelling selection behaviour. As a follow-up analysis,

consumer types related to this study will be profiled in terms of socio-demographic characteristics.

2.2 – Theory and Predictions

It is often argued that a substantial amount of consumer behaviour is unconscious and guided by

automated response processes (Dijksterhuis, Smith, van Baaren, & Wigboldus, 2005; Steg, & Vlek,

2009). In fact, much of consumer purchase behaviour in retail stores is said to occur ‘mindlessly’ and

‘automatically’, driven by norms (Cialdini, Kallgren, & Reno, 1991; Dijksterhuis et al., 2005). The

theory of normative social behaviour argues that norms have a strong impact on behaviour and that

norms often offer a decisional shortcut when one is choosing how to behave in a specific situation

(Cialdini et al., 1991). Norms describe what is typical or normal (Cialdini et al., 1991). In the situation

where consumers want to buy a specific food product in retail stores, they can opt for various items on

the shelf. For all that, ‘the norm’ is to pick the food item with the shortest remaining shelf life in front

of the shelf because of the ‘first in, first out’ (FIFO) shelf-filling principle employed by retailers

(Ferguson, & Ketzenberg, 2006). For that reason, many consumers will automatically pick the food

item with the shortest remaining shelf life in front of the shelf because that is the norm-consistent way,

without even thinking about it. However, it is not necessarily rational for consumers to pick the food

item in front of the shelf. As a matter of fact, when consumers would consciously think about which

food item to pick from the shelf, they might find it more desirable to opt for a food item further on the

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back of the shelf with a longer remaining shelf life (i.e. engage in date labelling selection behaviour).

The rationale behind this will be explained below.

Although automatic, almost thoughtless behaviour is said to be most common, it is expected that a

substantial part of consumers do engage in conscious decision-making when opting for a food item on

the shelf in retail stores, especially with regard to short and limited shelf life food products (Dijksterhuis

et al., 2005). Retailers often stock multiple food items of the same product on the shelf, with varying

date marks (Hug et al., 2005). When consumers want to buy a specific food product in retail stores some

may make a conscious decision as to which food item to choose from the shelf, thereby trading off pros

and cons between food items of the same product with differing date marks. In that case, consumers’

food item choice is likely to be determined by cost-benefit trade-offs (Ratchford, 1982; Ariely, &

Shampan’er, 2004). Each decision alternative has certain benefits associated with it as well as certain

costs (Payne, Bettman, & Johnson, 1991), and individuals will in turn choose alternatives with highest

benefits against lowest costs (Steg, & Vlek, 2009). This cost-benefit analysis may result in behaviour

that deviates from the norm (i.e. deliberately picking a food item from the back of the shelf, with a

longer shelf life) or behaviour that is consistent with the norm (i.e. deliberately picking the first food

item, with a shorter shelf life). But which costs and benefits do consumers perceive with respect to

picking food items with longer versus shorter shelf lifes? It is suggested in the literature that consumers

make use of date labels on food during the product decision-making process in retail stores to ensure

that they (1) will buy the freshest, finest quality food products and/or to ensure that they (2) will buy

food products that will give them the maximum amount of time to use up (i.e. consume) the food

products (WRAP, 2010). Furthermore, it is also suggested that some consumers deliberately pick the

food item with the shortest shelf life because of the altruistic reason of avoiding food waste (WRAP,

2010). Therefore, the following possible costs and benefit could be - fully or only partially - in place

during the trade-off and decision-making process of consumers with respect to whether or not to pick

the food item with the shortest remaining shelf life:

FOOD ITEM IN FRONT OF THE SHELF

COSTS BENEFITS

- A slightly less fresh food product

- Less flexibility with respect to when to consume the food product

- Less food waste

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In a sense, the cost side tends toward consumers’ self-interest whereas the benefit side is more in interest

of the overall collective good. This proposed cost-benefit trade-off therefore constitutes a clash between

consumers’ self-interest and collective interest; these interests are directly opposing one another. With

many other sustainability-related consumer decisions the self-interest and collective interest go hand in

hand. For example, self-interests and collective interests are aligned with respect to the sustainable

decision to turn off the lights when leaving the house (collective interest) and thereby saving money on

the energy bill (self-interest). Or, to give another example, buying an energy-saving refrigerator

(collective interest) later cuts costs with respect to the energy bill (self-interest). However, in the case

of selecting a specific food item from the shelf, pro-environmental behaviour has no self-interest. In

other words, consumers really have to decide between individual self-interest and the interest of the

community as a whole. The rational choice theory prescribes that people pursue their self-interest

(Miller, 2015). Furthermore, it is assumed by the standard economic theory that people often behave

rationally and therefore self-interestedly (Arrow, 1986). Therefore, when the proposed cost-benefit

trade-off would be the trade-off a consumer makes in real-life, it is assumed that a rational consumer

will be unlikely to opt for the food item with the shortest remaining shelf life. In other words, a rational

consumer is likely to engage in date labelling selection behaviour because self-interest outweighs

collective interest (i.e. costs outweigh the benefits).

Motives are the underlying reasons behind behaviour (Lyndhurst, 2011). So, if one wants to understand

why consumers engage in date labelling selection behaviour, one should examine which consumer

motives underlie this selection behaviour. Consumer motives in favour of date labelling selection

behaviour relate to the cost side of the proposed cost-benefit trade-off (a slightly less fresh food product

and less flexibility with respect to when to consume the food product), whereas consumer motives

against date labelling selection behaviour relate to the benefit side (less food waste). The three possible

consumer motives will now be discussed individually, and it will be tested later in this first study

whether these three motives are indeed important consumer motives in real-life.

I. The argument that food items in front of the shelf are slightly less fresh than food items

further on the back of the shelf, relates to quality perceptions of consumers. With respect

to these quality perceptions, it is assumed that consumers (often) infer greater quality of

food items that have a longer remaining shelf life, even if the difference in the length of the

remaining shelf life is very small (e.g. one or two days) (Aschemann-Witzel, J. Jensen, M.

Jensen, & Kulikovskaja, 2017; Newsome et al., 2014). Because of the perception that the

food item with a longer remaining shelf life is of (much) better quality, it is often preferred

over ‘older’ food items (Tsiros, & Heilman, 2005). However, this consumer perception is

incorrect; in reality quality does not fluctuate much during the shelf life of a food product

(Aschemann-Witzel et al., 2017). Only when the date mark of limited shelf life food

products has passed, the quality starts to deteriorate from its peak (Newsome et al., 2014).

12

The date mark is often set very conservatively because it is a manufacturer’s best guess as

to how long the food item will be at its best quality (Tsiros, & Heilman, 2005). However,

consumers often seem to assume that the difference in quality between a food item with the

shortest shelf life and a food item with a longer shelf life is of substantial difference, even

if the shortest shelf life food item is (often) only slightly ‘older’ and still long before expiry

(WRAP, 2010). This proposed consumer motive will be further referred to as the ‘higher

quality’ motive.

II. The argument that food items in front of the shelf offer less flexibility with respect to when

to consume the food than food items further on the back of the shelf, turns out to be an

often-reported reason by consumers of using date labels on food (Lyndhurst, 2011). This

flexibility argument has to do with the preference of consumers to have the maximum

amount of time possible to consume food (Lyndhurst, 2011). It is about having the option

to consume a food product somewhere ‘in the undetermined future’. Date labels aid

selection of the ‘best’ product in terms of the length of the remaining shelf life so that

consumers would have as long as possible to use food up (Lyndhurst, 2011). With respect

to flexibility, many consumers prefer food items with a longer/the longest remaining shelf

life. At first glance, it does not seem that this flexibility motive suffers from incorrect

consumer perceptions such as the ‘higher quality’ motive does. More flexibility seems to

be a fairly understandable consumer motive underlying date labelling selection behaviour.

However, although the rationale behind this flexibility motive seems well-grounded, there

are situations in which this motive seems less valid. For example, with respect to limited

shelf life food, consumers typically still have at least a week to consume the food item with

the shortest remaining shelf life. Therefore, it is questionable whether more flexibility is

really needed with respect to limited shelf life (semi-perishable) food products. To give

another example, in the situation in which consumers already have the intention to consume

the food product at short notice, the flexibility arguments seems to be a complete non-sense

argument. This proposed consumer motive will be further referred to as the ‘more

flexibility’ motive.

III. The argument that opting for food items in front of the shelf would lead to less food waste

than opting for food items further on the back of the shelf would, relates to consumers’

food waste awareness and importance attached to avoiding food waste. It is assumed that

some consumers are aware of the food waste streams caused by selecting food items with

a longer remaining shelf life, and do therefore select food items with the shortest remaining

shelf life (Theotokis, Pramatari, & Tsiros, 2012). However, it is questionable whether most

consumers actually associate date labelling selection behaviour with food waste. In other

words, are consumers really aware of the benefit side of the proposed cost-benefit trade-off

13

related to the food item in front of the shelf? The extent to which consumers are aware of

the fact that ‘date labelling selection behaviour’ leads to food waste is assumed to be

insufficient (Aschemann-Witzel et al., 2015). In addition, according to WRAP (2010), there

is a general lack of concern about (avoiding) food waste. Because of this, it is expected that

currently many consumers engaging in conscious decision-making do not face a trade-off

at all. It seems likely that consumers are solely aware of the cost side related to the food

item with the shortest shelf life which would make the decision rather easy. To elaborate,

when consumers are unaware of the benefits of picking the food item with the shortest

remaining shelf life, costs will automatically outweigh and have the upper hand which will

make the rational consumer pick the food item with a longer remaining shelf life (i.e. will

make them engage in date labelling selection behaviour). Therefore, it is questionable

whether the proposed cost-benefit trade-off always constitutes a personal, internal trade-

off and conflict. However, it sure represents a wider, social conflict surrounding date

labelling selection behaviour which would ideally be considered by all consumers at all

times. This proposed consumer motive will be further referred to as the ‘less food waste’

motive.

As a final remark, it will be attempted in this first study to weaken the ‘more flexibility’ motive by

trying to turn it into a non-sense argument, to see whether that influences the extent to which consumers

engage in date labelling selection behaviour. It is predicted that by eliminating the need for flexibility,

less consumers will engage in date labelling selection behaviour. Although not of primary focus, this

will be examined in order to see if there are in a sense ‘natural situations’ in which consumers are

more/less inclined to engage in date labelling selection behaviour. It was chosen to manipulate the ‘more

flexibility’ motive (and for example not the ‘higher quality’ motive) because it was intended to find a

natural situation in which a consumer motive underlying date labelling selection behaviour would not

be applicable. In other words, it was intended to find a situation in which consumers would be more/less

inclined to engage in date labelling selection behaviour, without needing (retailer) interventions or

consumer education.

2.3 – Methodology

2.3.1 – Experimental Design and Participants

The study consists of an online questionnaire where the real-life situation is simulated in which a

consumer (i.e. the participant) has to make a choice between which food item to buy in the supermarket,

accompanied by various follow-up questions. The study employs a two-group experimental design with

two conditions (moment of food consumption: ‘unspecified’ versus ‘on the same day of purchase’).

14

Each participant is randomly assigned to one condition. In condition 1, the moment of consumption is

unspecified. In condition 2, the moment of consumption is specified as being on the same day as the

day on which the food item is purchased. In condition 2, consumers’ need for flexibility with respect to

when to consume the food is in a sense eliminated. Because of the random assignment of participants,

any variation in the extent to which participants engage in date labelling selection behaviour and why

they do so can be attributed to the treatment of eliminating the need for flexibility through specifying

the moment of consumption to be on the same day of purchase. The manipulation is reflected in the

instruction each group receives.

For the data collection, primary data was collected through an online questionnaire which was sent to

the CentERpanel2, which represents a good reflection of the Dutch-speaking population. In total, 2023

members of the CentERpanel filled in the questionnaire (Mage = 56.47, SDage = 16.28; male = 53.2%,

female 46.8%). An overview of the sample characteristics can be found in Table 1. In total, 1036

participants were assigned to condition 1 and 987 participants were assigned to condition 2.

2.3.2 – Materials

In order to examine the extent to which consumers engage in date labelling selection behaviour, it is

necessary to simulate in the questionnaire the situation in the supermarket where consumers are about

to buy a specific limited shelf life food product and have to decide which product item on the shelf

2 The CentERpanel is part of the data collecting and research institute ‘CentERdata’. The CentERpanel consists of around 1900 households, who complete questionnaires via the Internet at home on a weekly basis against payment.

Percentage Absolute

Age

15 until 24 2.2 % 45 25 until 34 8.9 % 181 35 until 44 15.5 % 314 45 until 54 16.1 % 326 55 until 65 19.2 % 389 65 and older 38.0 % 768

Gender

Male 53.2 % 1077 Female 46.8 % 946

Education

Primary education 3.5 % 71 VMBO 23.8 % 481 HAVO/VWO 10.3 % 209 MBO 22.9 % 464 HBO 26.0 % 526 WO 13.4 % 272

Table 1 – Sample descriptives Study 1

15

(which one in the row) to pick. Therefore, the participants were exposed to a visual representation of a

supermarket shelf and were subsequently asked to indicate which item they would opt for. The product

selected for this study is yoghurt of 500 ml, based

on the assumption that yoghurt is prone to date

labelling selection behaviour as being a chilled,

limited shelf life food product. The visual

representation of the yoghurt shelf in the

supermarket encompasses seven yoghurts, with the

first two yoghurts having a date mark of the 15th of

March (oldest yoghurts) and the last five yoghurts

having a date mark of the 17th of March (youngest

yoghurts). Each yoghurt was assigned a number

from 1 to 7 (1 = yoghurt in front of the shelf, 7 =

yoghurt on the far back of the shelf). Figure 3 shows

the picture of the yoghurt shelf used in this study.

2.3.3 – Procedure and Measures

Procedure

Participants filled out the questionnaire online. First, participants received the following general

instruction when starting the questionnaire: ‘This questionnaire is about grocery shopping. We are

curious about how you make certain choices in the supermarket. There are no right or wrong answers.’

A more detailed briefing followed this instruction on the next screen, which was different for

participants assigned to condition 1 (moment of consumption ‘unspecified’) versus participants

assigned to condition 2 (moment of consumption ‘on the same day of purchase’):

- Condition 1: ‘You will soon see an image of a supermarket shelf with packages of yoghurt.

Imagine that you are shopping for groceries in the supermarket. You have a shopping list, but

you also just look around for other things. Because you sometimes have appetite for yoghurt in

the morning, you decide to get a pack of yoghurt.’

- Condition 2: ‘You will soon see an image of a supermarket shelf with packages of yoghurt.

Imagine that you are going to make a dessert for tonight for which you will need 500 ml of

yoghurt. You are in the supermarket to buy, among other things, a pack of yoghurt.’

Figure 3 – Picture used in experiment

16

As a final remark, it was mentioned to participants that for the success of the research is was important

to imagine that it was the 3rd of March on the day they filled out the questionnaire. The picture of the

yoghurts on the supermarket shelf was taken on the 3rd of March. Because the whole experiment

revolves around consumer decisions based on date marks, participants were requested to imagine it was

the 3rd of March to make the decision as realistic as possible. In that case, the yoghurt pack with the

shortest remaining shelf life would still have two weeks before reaching its date mark, allowing

sufficient time for consumers to consume the yoghurt (as was the case in the simulated real-life

situation).

Measures

The extent to which consumers engage in date labelling selection behaviour was measured via one

question referring to the picture in Figure 3 (shown on the same screen): ‘If you were planning to buy

a pack of yoghurt [if condition 2: for tonight’s dessert], which one would you take?’ (1 = yoghurt in

front of the shelf, 7 = yoghurt on the far back of the shelf). Participants did not engage in date labelling

selection behaviour if they chose a pack of yoghurt with assigned number 1 or 2 (date mark of March

the 15th), whereas participants did engage in date labelling selection behaviour if they chose a pack of

yoghurt with assigned number 3, 4, 5, 6 or 7 (date mark of March the 17th).

The consumer motives underlying date labelling selection behaviour were measured by various

successive questions as shown in Figure 4 on the next page. First of all it was asked whether participants

made a deliberate decision as to which yoghurt pack to select. If the answer was yes, participants were

subsequently asked why they opted for a particular yoghurt pack. With respect to consumer motives in

favour of date labelling selection behaviour, the extent to which the ‘more flexibility’ motive was an

important motive for consumers is assessed by the answer option ‘It gives me more time to consume

the yoghurt before it reaches its date mark’ whereas the ‘higher quality’ motive is assessed by the answer

option ‘I expect the yoghurt to taste better than the yoghurt with the shorter shelf life because it is

slightly fresher’. On the contrary, with respect to consumer motives against date labelling selection

behaviour, the extent to which the ‘less food waste’ motive was an important motive for consumers is

assessed by the answer option ‘I think it is a shame if the yoghurt packs with a shorter shelf life should

eventually be thrown away’. In addition, with respect to consumer motives against date labelling

selection behaviour, the extent to which consumers understand that the ‘higher quality’ and ‘more

flexibility’ motives are no – at least in this case – true costs of the food item in front of the shelf, is also

assessed. The importance attached by consumers to these motives is assessed by the answer option ‘The

yoghurt has twelve days until it reaches its date mark, which would give me enough time to consume

the yoghurt’, and the answer option ‘I expect the yoghurt to taste as good as the yoghurt with a longer

shelf life’. Noteworthy, the answer option ‘other, namely ..’ allows consumers to add other, personal

motives; in this way it is ensured that all possible consumer motives are incorporated in this study. The

complete questionnaire and accompanying set-up can be found in Appendix 1.

17

2.4 – Results

This results section is subdivided into two separate paragraphs. The first paragraph shows the results of

the main analysis addressing the research questions previously formulated, whereas the second

paragraph show the results of a follow-up analysis profiling several consumer types.

2.4.1 – Main Analysis

To start, some basic descriptive statistics are derived in order to get a first overall impression of the

results. For the sake of clarity, these descriptive results are presented in a flowchart (Figure 5).

Noteworthy, the answers that participants provided when selecting the open-ended ‘other, namely..’

Q1: 'If you were planning to buy a pack of yoghurt [if condition 2: for tonight's dessert], which one

would you take?'

Q2a: 'There were yoghurt packs on

the shelf with a date mark of March the

17th. Did you deliberately choose a yoghurt pack with

a date mark of March the 15th?'

'No I just picked a yoghurt pack in front of the shelf'

'Yes I deliberately picked a yoghurt pack with a

shorter shelf life'

Q3a: 'Why did you deliberately pick a yoghurt pack with a shorter shelf

life?'**choose the answer that applies to

you the most

'The yoghurt still has twelve days until it reaches its date mark, which would

give me enough time to consume the yoghurt'

'I expect the yoghurt to taste as good as the yoghurt with

a longer shelf life'

'I think it is a shame if the yoghurt packs with a

shorter shelf life should eventually be thrown away'

('less food waste' motive)

'Other, namely..'

Q2b: 'There were yoghurt packs on the shelf with a

date mark of March the 15th. Did you

deliberately choose a yoghurt pack

with a date mark of March the 17th?'

'No I just picked a yoghurt pack'

'Yes I deliberately picked a yoghurt pack with a longer

shelf life'

Q3b: 'Why did you deliberately pick a yoghurt

pack with a longer shelf life?'*

*choose the answer that applies to you the most

'It gives me more time to consume the yoghurt before

it reaches its date mark' ('more flexibility' motive)

'I expect the yoghurt to taste better than the yoghurt with

the shorter shelf life because it is slightly

fresher' ('higher quality' motive)

'Other, namely..'

Yoghurt Item 3, 4, 5, 6 or 7

Figure 4 – Flowchart of questionnaire items

Yoghurt Item 1 or 2

18

option to express their underlying motives, were recoded3; it appeared that, while recoding, none of the

provided answers were essentially different from the already existing answer options. Based on the

output of this study, the first, second, and (partially the) third research can now be answered.

‘To what extent do consumers engage in date labelling selection behaviour?’

The descriptive results displayed in Figure 5 provide insight into how big the share is of consumers that

engage in date labelling selection behaviour. The first research question can easily be answered by

comparing, within group 1 (moment of consumption ‘unspecified’), the percentage of participants that

chose a yoghurt pack with assigned number 1 or 2 with the percentage of participants that chose a

yoghurt pack with assigned number 3, 4, 5, 6, or 7. It appeared that, out of 1036 participants, 64.3

percent (666 participants) engaged in date labelling selection behaviour whereas 35.7 percent (370

3 Originally, in condition 1 (moment of consumption ‘unspecified’), out of the participants (not) engaging in date labelling selection behaviour, 2.3 (2.4) percent selection the ‘other’ option. In condition 2 (moment of consumption ‘on the same day of purchase’) out of the participants (not) engaging in date labelling selection behaviour, 6.2 (4.4) percent selected the ‘other’ option.

Moment of Consumption:

Group 1. Unspecified (n = 1036)Group 2. On the same day of

purchase (n = 987)

Picked a yoghurt with the shortest remaining shelf life (March the 15th) with assigned

number 1 or 2

35.7% 54.4%

Non-deliberate choice43.8%40.1%

Deliberate choice*56.2%59.1%

'Still enough time for consumption'

70.2%61.4%

'Equally good taste'2.4%3.1%

'Shame if these yoghurts would be thrown away'

27.4%35.5%

'Other'0.0%0.0%

Picked a yoghurt with a longer remaining shelf life (March the 17th)

with assigned number 3, 4, 5, 6, or 7

64.3%45.6%

Non-deliberate choice2.4%3.1%

Deliberate choice*97.6%96.9%

'More time for consumption'

90.0%86.2%

'Better taste because its fresher' 10.0%13.8%

'Other'0.0%0.0%

Figure 5 – Descriptive results Study 1 * Only one answer possible: ‘choose the answer that applies to you the most’.

19

participants) did not. So almost two-thirds of the participants (i.e. the vast majority) engaged in date

labelling selection behaviour.

‘Why do consumers engage in date labelling selection behaviour?’

The descriptive results displayed in Figure 5 also provide insights with respect to the second research

question as to which consumer motives underlie date labelling selection behaviour. As predicted, with

regard to group 1 (moment of consumption ‘unspecified’) it turned out that almost all participants (97.6

percent) who engaged in date labelling selection behaviour deliberately and consciously did so. In other

words, these 97.6 percent out of all participants engaging in date labelling selection behaviour made a

deliberate choice to pick a yoghurt pack from the shelf with a longer remaining shelf life. With respect

to the proposed underlying motives, it appeared that the ‘more flexibility’ motive was by far the most

important reason (90 percent) for participants to engage in date labelling selection behaviour. In

contrast, only 10 percent of participants argued that they engaged in date labelling selection behaviour

out of ‘higher quality’ reasons. It turns out that, in the general situation of uncertainty with respect to

when to consume the food (i.e. the yoghurt), participants who engage in date labelling selection

behaviour predominantly do so because that will give them more time to consume the yoghurt before it

reaches its date mark. Not surprisingly, unconsciously, non-deliberately picking a yoghurt pack from

the shelf with a longer remaining shelf life represents an almost non-existing subgroup (2.4 percent).

With respect to group 1 (moment of consumption ‘unspecified’), it remarkably turned out that out of

the participants who did not engage in date labelling selection behaviour, merely 43.8 percent indicated

that they ‘just picked a yoghurt pack from the shelf’ when asked whether they deliberately picked a

yoghurt pack in front of the shelf or not. In fact, most participants (56.2 percent) who did not engage in

date labelling selection behaviour, indicated that they deliberately opted for a yoghurt pack in front of

the shelf with the shortest remaining shelf life. In other words, the behavioural act of picking a food

item in front of the shelf appears to be not as automatic and thoughtless as one would expect it to be.

However, we may have turned this consumer behaviour into more conscious and deliberate behaviour

than it actually is in reality. By asking participants directly whether their choice was deliberate or not,

it could be that these participants started to think about their behaviour more than they would normally

do. Nonetheless, picking a food item in front of the shelf turned out to be much less of a conscious and

deliberate act compared to picking a food item further on the back of the shelf (43.8 percent versus 2.4

percent). Interestingly, with respect to the participants who indicated to have deliberately picked a

yoghurt pack in front of the shelf, the ‘less food waste’ motive turned out to be not so salient. When

participants deliberately picked a yoghurt pack in front of the shelf, the ‘less food waste’ motive was

not the most important reason for participants. In fact, the primary, most important reason for

participants to deliberately pick the yoghurt pack in front of the shelf was because that they believed

that yoghurt pack would still give them enough time for consumption before it would reach its date

20

mark (70.2 percent). Furthermore, 2.4 percent deliberately picked a yoghurt pack in front of the shelf

because they expected that that yoghurt pack tasted as good as yoghurt packs with a longer remaining

shelf life on the back of the shelf. It could thus be argued that the link between date labelling selection

behaviour and its contribution to food waste is not yet strong enough, or it could be that participants do

not care enough about food waste.

‘When are consumers more/less inclined to engage in date labelling selection behaviour?’

It was additionally attempted to disempower the ‘more flexibility’ motive by eliminating the need for

flexibility with respect to when to consume the yoghurt, thereby trying to turn the flexibility argument

into a non-sense argument. Are consumers less inclined to engage in date labelling selection behaviour

when the intended moment of consumption is on the same as the day on which the food (i.e. the yoghurt)

is purchased? By looking at the results provided in Figure 5, it seems that the extent to which consumers

engage in date labelling selection behaviour is more profound in case one is uncertain about when to

consume the yoghurt (64.3 percent) than when one has the intention of consuming the yoghurt on the

same day of purchase (45.6 percent). Whether or not consumers engage in date labelling selection

behaviour is significantly determined by the manipulation of the moment of consumption (Wald χ2 (1)

= 70.520, p < .001; Appendix 2). Noteworthy, the elimination of the need for flexibility as a motive has

weakened the extent to which consumers engage in date labelling selection behaviour, but did not lead

to a complete disappearance of this selection behaviour; in group 2 (moment of consumption ‘on the

same day of purchase’) still nearly half of the participants (45.6 percent) engaged in date labelling

selection behaviour. Furthermore, because the need for flexibility was in a sense eliminated, one would

expect that consumers who still engaged in date labelling selection behaviour did so out of the ‘higher

quality’ motive. Remarkably, however, 86.2 percent out of the participants still deliberately engaging

in date labelling selection behaviour (with the intention of consuming the yoghurt on that same day) did

so out of the ‘more flexibility’ motive. In other words, although the ‘more flexibility’ motive is slightly

toned down and a less important reason for participants that had the intention of consuming the yoghurt

on the same day (86.2 percent) compared to participants where the moment of consumption was

uncertain (90 percent) (Wald χ2 (1) = 17.916, p < .001; Appendix 2), 86.2 percent still represents a

substantially high percentage. It turns out that the ‘more flexibility’ motive is a very persistent motive

which is difficult to disempower. Although it was attempted to eliminate the need for flexibility by

trying to turn it into a non-sense argument, it seems that for many participants (86.2 percent) it was

never a non-sense argument. Even though the participants in group 2 were instructed that the intended

moment of consuming the yoghurt was on the same day of purchase, many participants might have kept

21

thinking (for whatever reason) ‘but what if tonight’s dessert does not take place?’4 In that case,

flexibility with respect to when to consume the yoghurt might be desirable.

2.4.2 – Follow-up Analysis: Consumer Profiling

The aim of this follow-up analysis is to profile consumer types related to this study. For instance, what

is the typical profile of a consumer that engages in date labelling selection behaviour in retail stores?

More specifically, in this study three types of consumers appeared that can in turn be profiled:

1. Consumers that unconsciously comply with the norm by automatically selecting the food

item in front of the shelf with the shortest shelf life (Group 1)

2. Consumers that consciously deviate from the norm by deliberately selecting the food item

further on the back of the shelf with a longer shelf life (Group 2)

3. Consumers that consciously comply with the norm by deliberately selecting the food item

in front of the shelf with the shortest shelf life (Group 3)

Consumers in a particular subset often share similar characteristics. There are a number of consumer

characteristics (i.e. segmentation bases) that can be used for profiling and segmenting consumers

(Wedel, & Kamakura, 2012). In fact, there are three main types of segmentation bases; decriptive,

behavioural and benefit bases (Wedel, & Kamakura, 2012). In this follow-up analysis, consumers will

be profiled on a descriptive bases (i.e. on socio-demographic variables) because the CentERpanel

contains a lot of background information from panel members with respect to socio-demographic

characteristics. The three identified consumer groups were profiled on several of these socio-

demographic variables (see Table 2 on the next page). To be more precise, the following variables are

examined (with ANOVA’s5 and crosstabs with Pearson χ2); ‘age’, ‘gender’, ‘education’, ‘net monthly

income in the household’, and ‘number of members in the household’. Age, education, net monthly

income in the household, and number of members in the household significantly differ between the

three consumer groups (see Table 2). Surprisingly, there are no differences in gender between the

groups.

To elaborate, it appeared that consumers over the age of 65 are relatively more likely to deliberately

engage in date labelling selection behaviour than other age categories, whereas consumers between the

age of 15 and 24 are relatively less likely to engage in selection behaviour compared to other age

4 In the open-ended answer option ‘Other, namely ..’, two participants mentioned explicitly that ‘maybe tonight’s dessert will not go on, and then I need more time to consume the yoghurt’ 5 Levene’s test for homogeneity of variances for ‘number of members household’ was significant (p = . 033) implying unequal variances and a Games-Howell post hoc test with respect to Table 2. Levene’s test for homogeneity of variances for the natural logarithm of ‘net monthly income household’ was nonsignificant (p = .410) implying equal variances and a Tukey’s post hoc test with respect to Table 2

22

categories. Consumers between the age of 15 and 24 are relatively more likely to automatically and

unconsciously select the food item in front of the shelf, but still 48.9 percent engaged in date labelling

selection behaviour. Furthermore, it appeared that the higher educated consumers are, the less likely

they are to engage in date labelling selection behaviour and the more likely they are to deliberately and

consciously select a food item in front of the shelf. In addition, consumers that deliberately decide to

select a food item in front of the shelf, often have a higher net monthly household income than

consumers that deliberately decide to select a food item further on the back of the shelf (i.e. engage in

date labelling selection behaviour) and than consumers that automatically select a food item in front of

the shelf. Finally, it appeared that consumers that deliberately decide to select a food item in front of

the shelf, often have slightly bigger households (i.e. a larger number of members in the household) than

consumers that deliberately decide to select a food item further on the back of the shelf. With respect

to bigger households, consumers could argue that the food will be consumed anyways. The consumer

that automatically and unconsciously selects a food item in front of the shelf hardly differs, on this

socio-demographic characteristic of number of members in the household, from the consumer that

deliberately and consciously selects the food item in front of the shelf and further on the back of the

shelf.

GROUP 1

In front of the shelf,

non-deliberate

(n = 378)

GROUP 2

On the back of the

shelf, deliberate

(n = 1116)

GROUP 3

In front of the shelf,

deliberate

(n = 529)

Socio-demographic variables Statistic p

Age 15 – 24 years (%) 31.1 48.9 20.0

Age 25 – 34 years (%) 17.7 54.7 27.6

Age 35 – 44 years (%) 19.7 51.9 28.3

Age 45 – 54 years (%) 19.0 52.8 28.2

Age 55 – 64 years (%) 14.7 54.8 30.6

Age 65 + (%) 19.6 58.3 22.2

Age in categories χ2 (10) = 19.871 < .05

Male (%) 19.9 53.6 26.6

Female (%) 17.2 57.0 25.7

Gender χ2 (2) = 3.084 > .05*

Basisonderwijs (%) 28.2 63.4 8.5

VMBO (%) 17.1 61.7 21.3

HAVO/VWO (%) 21.1 55.5 23.4

MBO (%) 15.5 56.3 28.2

HBO (%) 19.8 50.2 30.0

WO (%) 20.3 49.1 30.6

Education in CBS-categories χ2 (10) = 36.112 < .05

Net monthly income household (mean)** 7.87b 7.87b 7.96a F (2) = 5.969 < .05

Number of members household(mean) 2.39ab 2.39b 2.55a F (2) = 3.349 < .05

Note: the different superscripts (a-b) indicate significant statistical differences (p < .05) * p = .214 ** The natural logarithm of ‘net monthly income household’ was used in this analysis

Table 2 – Socio-demographic characteristics per consumer group

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2.5 – Preliminary Conclusion

To conclude, it turned out that in the case of yoghurt, almost two-thirds of the participants engaged in

date labelling selection behaviour. Furthermore, it turned out that the ‘more flexibility’ motive was by

far the most important reason for participants to engage in date labelling selection behaviour. At the

same time, the ‘more flexibility’ argument proved to be a very persistent and hard to disempower

consumer motive underlying selection behaviour. Nonetheless, consumers turned out to be less likely

to engage in date labelling selection behaviour when they had the intention to consume the food on the

same day of purchase. To end, it appeared from the consumer profiling that consumers are relatively

less likely to engage in date labelling selection behaviour when they are higher educated, have a higher

net monthly household income, have a bigger household, and when they are aged fifteen to twenty-four

(as opposed to older).

24

25

Study 2

3.1 – Purpose

This study represents a first attempt at finding an effective solution to successfully intervene with

consumer’s date labelling selection behaviour in retail stores. Primarily, this small-scale follow-up

study aims to seek answer to the fourth research question: ‘What can the retailer do about date labelling

selection behaviour?’ In other words, it will be assessed what the retailer could do to improve consumer

acceptance of food items with the shortest remaining shelf life. In addition, various situations will be

examined in which consumers are suggested to be more/less inclined to engage in date labelling

selection behaviour, since this could potentially impact the effectiveness of retailer interventions.

3.2 – Theory and Predictions

According to the ‘ABC’ (Antecedents, Behaviour, and Consequences) model of behavioural change,

behavioural interventions can either be classified as antecedent-focused strategies or consequence-

focused strategies (Lehman, & Geller, 2004). In this second study it was decided to make use of

antecedent-focused strategies for behavioural change; it is attempted to intervene with the causes (i.e.

antecedents) of consumer behaviour. In other words, an attempt was made to influence consumer

behaviour by influencing the underlying consumer motives. To specify, one possible way to counteract

consumer’s date labelling selection behaviour is to take away the consumer motives underlying this

selection behaviour. It can be argued that in the battle against date labelling selection behaviour, the

retailer could either try to eliminate or at least disempower consumer motives in favour of this selection

behaviour or the retailer could try to reinforce or enhance consumer motives that work against this

selection behaviour. In other words, in order to increase acceptance of food items in front of the shelf

with the shortest remaining shelf life, one could try to take away or weaken the cons (costs) or

emphasize the pros (benefits) of those food items. Therefore, as became apparent from the first study,

there are essentially three possible ways to approach the problem of date labelling selection behaviour:

One could try to eliminate or disempower the ‘higher quality’ motive (I) or the ‘more flexibility’ motive

(II), or one could try to enhance the ‘less food waste’ motive (III).

Based on the results of the first study as well as the general consensus that consumers are insufficiently

aware of the food waste streams caused by date labelling selection behaviour (Aschemann-Witzel et al.,

2015), raising the concern about (avoiding) food waste could be a way to go for retailers in order to

intervene with consumer’s selection behaviour. In fact, in the current, general fight against food waste,

retail stores often employ strategies that emphasize waste issues in an attempt to create awareness and

to reinforce consumers’ collective interest. An example of such a strategy can be given with reference

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to ‘Albert Heijn’ and its often-recurring message “It’s a shame to throw it away”6 addressed at (often

perishable) food items that are about to expire. However, in the current context of limited shelf life food

products, it may not always be logical to attach an “It’s a shame to throw it away” message to food

items closest to expire because it could perfectly be that those food items will not expire in one or two

weeks. In that case, such a message might be odd and incomprehensible for consumers: “Why would a

retailer throw away this food item, while it will not reach its date mark in (e.g.) two weeks?” Therefore,

in this context, much more would be needed than merely attaching this message to the food item in

front of the shelf. Besides, it is generally argued that self-interest is often the primary basis for economic

decisions (Miller, 2015). According to the literature, it is easier to motivate individuals to pursue their

self-benefits than collective benefits (Frantzich, 2008). In other words, it is often suggested in the

literature that individuals are more inclined to act out of self-interest than to act purely out of interest

of the collective good (Miller, 2015). Because of all this, as a retailer intervention it is decided to not

employ a food waste campaign that tries to enhance collective interest.

As a matter of fact, it became apparent from the first study that consumers engage in date labelling

selection behaviour primarily out of flexibility reasons and some out of higher quality reasons. The

perception of slightly lower quality and less flexibility (often) form the self-centered ‘costs’ for

consumers to select a food item in front of the shelf with the shortest remaining shelf life. The retailer

interventions in this second study will focus on these ‘higher quality’ and ‘more flexibility’ motives. In

order to disempower these consumer motives in favour of date labelling selection behaviour, and

therefore to increase acceptance of the food item in front of the shelf, it should in a way be made clear

by retailers to consumers that:

I. The difference in quality between a food item with the shortest shelf life and a

food item with a longer shelf life is actually negligible and almost non-existing

(Aschemann-Witzel et al., 2017)

II. There is still enough time to consume the food item with the shortest shelf life

before the food item reaches its date mark

If retailers could in a way explain this to consumers, consumers might start to re-think and reconsider

their behaviour in retail stores. Ideally, consumers will then realise that date labelling selection

behaviour is undesirable by linking this selection behaviour to food waste. Thus, weakening the

arguments that drive date labelling selection behaviour could indirectly raise consumers’ food waste

awareness and concern.

The question turns into how to turn this into retailer interventions. In this second study, as a first attempt

to intervene with date labelling selection behaviour, it was decided to work with persuasive messages

6 In Dutch: “Weggooien is zonde”

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aimed at consumers at the moment-of-purchase in retail stores. It is often argued that interventions

applied at the moment-of-purchase are most effective in encouraging behavioural change (Young et al.,

2018). The content of the persuasive messages will be aimed at disempowering either the ‘higher

quality’ motive or the ‘more flexibility’ motive. It is predicted that persuasive messages that challenge

underlying motivations for date labelling selection behaviour will be effective in attenuating the extent

to which consumers engage in this behaviour. Based on this, the following hypothesis is formulated:

• H1: Consumers that are exposed to a message that challenges an underlying motivation for date

labelling selection behaviour will be less likely to engage in date labelling selection behaviour

than consumers that are not exposed to such a message.

Furthermore, it became apparent from the first study that the ‘more flexibility’ motive was by far the

most important consumer motive in favour of date labelling selection behaviour. Because of this, it is

predicted that the message aimed to disempower the ‘more flexibility’ motive will be most effective in

attenuating the extent to which consumers engage in date labelling selection behaviour. Based on this,

the following hypothesis is formulated:

• H2: Consumers that are exposed to the flexibility-related message will be less likely to engage

in date labelling selection behaviour than consumers that are exposed to the

quality-related message.

These hypotheses were tested in an experiment among Tilburg University students.

3.3 – Methodology

3.3.1 – Experimental Design and Participants

The study consists of two parts: The first part consists of a shopping task that takes place in a simulated

supermarket environment (i.e. the ‘actual’ experiment), followed by an online post-experiment

questionnaire. In the shopping task, participants have to make a choice which food item to buy. The

study employs a between-subjects experimental design with four conditions resulting from the

manipulation of the type of message (no message, neutral message, flexibility-related message, and

quality-related message). In the next section, the manipulation of the type of message will be explained

in more detail. The experiment examines the effectiveness of different messages in reducing consumer’s

date labelling selection behaviour. Participants are randomly assigned to one of the four message types.

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For the data collection, primary data was collected in Tilburg University’s CentERlab7, where

participants were placed in individual cubicles. Dutch speaking Tilburg University students were

recruited and invited to the lab to participate in the study. In total, 96 Tilburg University students

participated (Mage = 21.03, SDage = 2.00; male = 41.7%, female = 58.3%). Each of the four ‘type of

message’ conditions contained 24 participants. In general, the participants indicated to be prone to date

labelling selection behaviour (“tendency to engage in date labelling selection behaviour”, M = 4.98 (SD

= 1.42) on a 7-point scale), and to have the intention to not waste food (“intention to avoid food waste”,

M = 5.23 (SD = 1.32) on a 7-point-scale). As will be explained in more detail in the next sections, it

was chosen to work with yoghurt drink products with respect to the shopping task. The majority of the

participants liked yoghurt drink (94.8 percent) and indicated to sometimes buy yoghurt drink (71.9

percent). The study was conducted between May the 29th and June the 5th. Participants received a

payment of 5 euro in return for their participation.

3.3.2 – Manipulation of the Type of Message

In this study, the type of message was manipulated. Three different messages were used: A neutral

message (‘Pick me’), a flexibility-related message (‘Pick me: you still have sufficient time to drink

me’), and a quality-related message (‘Pick me: I’m just as tasty as my friends behind me’). The neutral

message was added as a control condition in order to rule out the possibility of the effects being solely

attributable to a ‘label’ effect (i.e. any label would reduce selection behaviour). To continue, retailers

often make use of sticky labels attached to food items to communicate (for example) a discount to

consumers. In this study it is decided to use such labels as a way to communicate the aforementioned

three messages to consumers. Therefore, the message manipulation is reflected by different labels stuck

onto food items in front of a shelf with the shortest remaining shelf life (see Figure 6).

3.3.3 – Materials

Based on the three different messages, three brightly coloured labels were designed (see Figure 6).

Attention is often drawn to objects that strongly contrast with the background (Yarbus, 1967). Using

bright colours to contrast an object from its background increases one’s ability to detect the object

(De Vries, Hooge, Wertheim, & Verstraten, 2013). Because the study was conducted in Dutch, the

messages on the labels were also formulated in Dutch.

7 CentERlab is CentER’s facility for conducting economic and business experiments at Tilburg University. CentERlab consists of a computerized laboratory containing 10 individual cubicles.

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In the shopping task, it was examined whether the different messages printed on labels were effective

in reducing the extent to which consumers engage in date labelling selection behaviour. In order to

examine whether the different messages have an effect on which food items participants pick, it is

necessary to simulate a supermarket environment including associated product shelves and prices.

Figure 7 shows the simulated supermarket yoghurt shelf. In order to increase external validity, it was

attempted to realistically mimic and reconstruct the yoghurt shelf as accurately as possible compared to

how it looks like in actual retail stores. Participants

were taken to a separate individual cubicle in the lab

where they encountered the simulated product shelf

with three different types of yoghurt drink (500 ml).

Each type of yoghurt drink had 6 items (i.e. packs)

placed on the shelf (18 packs in total), with the

associated price situated on top of the shelf. It was

chosen to work with yoghurt drinks because of the

assumption that yoghurt drinks are prone to date

labelling selection behaviour as being a chilled,

limited shelf life product. The three different variants

of yoghurt drink used, together with the date marks on

the six items, were:

- ‘Optimel Raspberry’ the first three on the shelf 05 - 06, the last three on the shelf 12 - 06

- ‘Optimel Lime’ the first three on the shelf 07 - 06, the last three on the shelf 12 - 06

- ‘Vifit Red Fruits’ the first three on the shelf 06 - 06, the last three on the shelf 13 - 06

The yoghurt drinks on the simulated product shelf were an exact copy of a yoghurt shelf in the

supermarket, as were the associated prices. To be able to record choices, each yoghurt drink (per type)

was assigned a small number from one to six written on the bottom of the item (1 = in front of the shelf,

Figure 7 – Yoghurt drink shelf used in experiment

Figure 6 – Labels used in experiment (type of message from left to right: neutral, flexibility-focused, quality-focused)

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6 = on the back of the shelf). Next to the simulated shelf lay a piece of paper with the message ‘please

place the pack of yoghurt drink of your choice on this paper’.

3.3.4 – Procedure and Measures

Procedure

Tilburg University students were invited to the lab and placed in an individual cubicle. Participants

were instructed that the experiment was about how consumers make choices between products in the

supermarket. It was explained that they were soon taken, by the lab assistant, to another cubicle where

a refrigerated product shelf of a supermarket was simulated. The participants were instructed to imagine

that it was a real supermarket and that they had the intention to buy a yoghurt drink package.

Furthermore, it was instructed that they should select their preferred yoghurt drink (i.e. the yoghurt

drink that they would buy) out of the eighteen presented packs of yoghurt drink, exactly as they would

do in real-life. Finally, participants were informed that when they were done with the shopping task

they had to fill in a short post-experiment questionnaire online. The exact instruction given to

participants (in Dutch) can be found in Appendix 3. After participants received the instruction, they

were taken by the lab assistant to another cubicle for the shopping task. After participants placed the

yoghurt drink of their choice on the designated spot they were brought back, by the lab assistant, to

their initial cubicle to fill in the post-experiment questionnaire. In the meantime, the lab assistant

recorded (after every participant) the corresponding number of the selected yoghurt drink pack.

Before the actual experiment took place, a small pre-test was conducted on the 28th of May to ascertain

that the online instruction given prior to the shopping task was clear (n = 7; Mage = 23.29, SDage = 2.29;

male = 71.4%, female = 28.6%). After participants in the pre-test completed the shopping task they

were asked whether everything was clear with respect to what was expected from them. It appeared it

was not clear they could choose from all eighteen yoghurt drinks, so this was added for clarification in

the instruction. Additionally, the statement ‘the lab assistant will put everything back in place after you

have finished the shopping task’ was added to the instruction to clarify that it was okay to rumble around

on the shelf.

Measures

In the shopping task, the extent to which consumers engage in date labelling selection behaviour was

measured on the basis of participants’ product choice. If participants chose a yoghurt drink pack with

assigned number 1, 2, or 3 they did not engage in date labelling selection behaviour. On the contrary, if

participants chose a yoghurt drink pack with assigned number 4, 5 or 6 they did engage in date labelling

selection behaviour because these yoghurt drink packs had a longer remaining shelf life.

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In the post-experiment questionnaire, supplementary background information of participants was

obtained that could be linked to participants’ choice behaviour in the shopping task. The gathered

background information relates to the extent participants define themselves as someone engaging in

date labelling selection behaviour with respect to limited shelf life food products (such as yoghurt

drink), and to the extent participants have the intention not to waste food.

The tendency to engage in date labelling selection behaviour was measured via three items on a 7-

point scale (1 = certainly not, 7 = most certainly): ‘I usually pay close attention to date marks’, ‘I usually

consciously take a product with a long shelf life’, and ‘I usually take the product in front of the shelf or

on top of a pile’8.

Intention to avoid food waste (Visschers, Wickli, & Siegrist, 2016; Stancu, Haugaard, & Lahteenmaki,

2016) was measured via three items on a 7-point scale (1 = certainly not, 7 = most certainly): ‘I think it

is a shame to throw away food’, ‘I am consciously trying to waste as little food as possible’, and ‘I think

food waste is a big problem’.

In addition, the post-experiment questionnaire also contained some control questions to assess whether

participants had noticed the message labels in the first place. Participants were asked whether or not

they had seen a label on some of the packs of yoghurt (‘You have just seen the shelf with packs of

yoghurt drink, have you seen a label on (some of) the packs of yoghurt drink?’). In the case participants

answered that they had seen a label, it was asked what they believed was written on the label in the

form of an open-ended question (‘If so, what do you believe was written on the label?’). Furthermore,

participants were asked whether or not they liked yoghurt drink and whether or not they ever buy

yoghurt drink. The post-experiment questionnaire (in Dutch) can be found in Appendix 4.

3.4 – Results

This results section is subdivided into two separate paragraphs. The first paragraph shows the results of

the main analysis that tests whether the messages were effective in reducing date labelling selection

behaviour, whereas the second paragraph shows the results of several follow-up analyses.

3.4.1 – Main Analysis

In the shopping task, participants selected their preferred yoghurt drink package from a small

assortment. Based on participants’ product choice, it is derived whether or not participants engage in

date labelling selection behaviour. Table 3 provides the descriptive results.

8 Within the overall construct the third item ‘I usually take the product in front of the shelf or on top of a pile’ was reverse-coded.

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Type of Message (n = 96) Not engaging in date labelling selection behaviour (yoghurt # 1, 2, 3)

Engaging in date labelling selection behaviour (yoghurt # 4, 5, 6)

1. No message 11 (45.9 %) 13 (54.1 %) 2. Neutral 11 (45.9 %) 13 (54.1 %) 3. Flexibility-related 11 (45.9 %) 13 (54.1 %) 4. Quality-related 13 (54.1 %) 11 (45.9 %)

Total: 46 (47.9 %) Total: 50 (52.2 %) Table 3 – Descriptive results Study 2

Overall, slightly more than half of the participants (52.2 percent) engaged in date labelling selection

behaviour. In the intervention-free ‘no message’ condition, 54.1 percent of the participants (in contrast

to 64.3 percent of the participants in Study 1) engaged in date labelling selection behaviour. This finding

is consistent with the first study, where it was detected that higher educated and younger consumers

were less likely to engage in date labelling selection behaviour.

The primary question is whether the extent to which participants engage in date labelling selection

behaviour differs significantly between the type of message conditions. Hypothesis 1 predicted that

participants that are exposed to a message that challenges an underlying motivation for selection

behaviour, are less likely to engage in date labelling selection behaviour than participants that are not

exposed to such a message. Furthermore, hypothesis 2 predicted that participants that are exposed to

the flexibility-related message would be less likely to engage in date labelling selection behaviour than

participants that are exposed to the quality-related message. In order to test these two hypotheses, a

logistic regression was conducted with type of message as the independent variable and whether or not

participants engage in date labelling selection behaviour as binary dependent variable. The logistic

regression shows that the overall effect of the type of message on date labelling selection behaviour is

not significant (Wald χ² (3) = .499, p = .919). In other words, date labelling selection behaviour did not

significantly differ between the message types, rejecting hypothesis 1. Despite the nonsignificant

overall effect of message type, pairwise differences in date labelling selection behaviour between the

message types were examined as follow-up in the next section. In contrast to hypothesis 2, the logistic

regression did not reveal a difference in date labelling selection behaviour between the flexibility-

related message and the quality-related message (Wald χ² (1) = .333, p = .564). Therefore, the second

hypothesis is also rejected with respect to this study. The output of the logistic regression can be found

in Appendix 5.

3.4.2 – Follow-up Analysis: Moderators of the type of message effect

Unfortunately, no significant message effect was found; the message interventions turned out not to

have the derised negative effect on date labelling selection behaviour. In order to try to understand why

the messages were ineffective, several follow-up analyses were performed. Note, however, that sample

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size is relatively small and hence the follow-up analyses are in fact underpowered. Nonetheless, we

believe it is valuable to look for patterns in the data as these insights could serve as potential input for

further research. We identified three potential moderators of the effect of the messages:

1. The time until expiry

2. Participants’ a priori intention to avoid food waste

3. The extent to which participants noticed the message labels

Time until expiry

To start, it could be the case that the messages had an insignificant overall effect on whether or not

participants engaged in date labelling selection behaviour because while each day passed by during the

experiment, the date marks of the yoghurt drinks came closer and closer. It could be that in the beginning

of the experiment the messages were effective, but later on in the experiment they turned ineffective (or

even backfired). It is predicted that over time more participants engaged in date labelling selection

behaviour in the experiment, because the expiry date mark of the yoghurt drinks came closer and closer

over time allowing for less flexibility with respect to when to consume the yoghurt. As such, especially

the flexibility-related message may backfire when flexibility is actually low. Therefore, it is examined

whether ‘time’ moderates the effect the message interventions have on date labelling selection

behaviour of consumers. Time was entered in the logistic regression model as a linear term ranging

from -2.5 (day one) to 2.5 (day six). Potential non-linear effects of time were captured by a quadratic

term. Finally, interactions between the type of message and time (linear and quadratic) were included

in the model, to examine the effectiveness of different types of messages over time. It was chosen to

use ‘time in days’ because of the assumption that the tendency to engage in date labelling selection

behaviour increases by the day. The model results reveal that none of the effects are significant (all ps

> .05), which may be due to power problems. Nonetheless, it might still be valuable to look for patterns.

Figure 8 (on the next page) shows the predicted probability that a yoghurt drink with the shortest

remaining shelf life (i.e. in front of the shelf) is selected for the different message types over time.

Although the effect of ‘time’ is insignificant, the negative time trend is in the expected direction (b =

-.239). Looking at the simple slopes, we find negative (but insignificant) time trends for all types of

messages (no message: b = -.239, flexibility-related message: b = -.529, quality-related message: b =

-.191), except – somewhat surprisingly – for the neutral message (b = +.110). Interestingly, while the

quality-related message seems to mitigate date labelling selection behaviour over the course of time

(compared to no message at all), the flexibility-related message seems to accelerate date labelling

selection behaviour when moving towards the expiration date. This is consistent with the idea that the

flexibility-related message backfires when flexibility is actually low (essentially turning the message

into a false claim). However, note that none of these effects reaches significance. The model results can

be found in Appendix 6A.

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Intention to avoid food waste

It could also be that the messages did not significantly affect date labelling selection behaviour because

the message interventions were only effective for participants that are concerned about food waste and

have the intention to avoid food waste in the first place. In other words, it could be that the effect of the

messages are more profound for participants who have a stronger (versus weaker) intention to avoid

food waste. Therefore, it is examined whether ‘intention to avoid food waste’ moderates the effect the

message interventions have on the extent to which participants engage in date labelling selection

behaviour. In the post-experiment questionnaire, the self-reported intention of participants to avoid food

waste was measured via three items each on a 7-point scale (Cronbach’s Alpha = .854)9 and this

‘intention to avoid food waste’ was added to the logistic regression model. The model results reveal

that the interaction between ‘type of message’ and ‘intention to avoid food waste’ is insignificant (Wald

χ² (3) = 4.404, p = .221), which may be due to power problems. Nonetheless, it might still be valuable

9 Overall construct was created under the assumption that each item is equally important (i.e. same unit weights)

Figure 8 – Graphical visualization of the effect of type of message over time, on the probability of selecting a yoghurt drink with the shortest shelf life.

35

to look for other patterns and trends in the data. Therefore, a follow-up analysis was conducted to

estimate the simple effects of the type of messages separately for participants with low intention to

avoid food waste and for participants with high intention to avoid food waste (based on a median split).

Results are displayed in Figure 9. However, the model results reveal that the simple effects of the

messages for participants with low intention to avoid food waste and for participants with high intention

to avoid food waste separately, are nonsignificant (all ps > .05). Despite the insignificant effects, the

model results do reveal some interesting patterns. Participants with high intention to avoid food waste

have the tendency to engage less in date labelling selection behaviour in the presence of a message label

(compared to no message at all), particularly with respect to the flexibility-related message (b = 1.099)

and the quality-related message (b = .0693). On the contrary, participants with low intention to avoid

food waste have the tendency to engage more in date labelling selection behaviour in the presence of a

message label (compared to no message at all), especially with respect to the flexibility-related message

(b = -1.281). However, recall that none of these effects reaches significance. The model results can be

found in Appendix 6B.

Figure 9 – Graphical visualization of the effect of type of message, per low or high intention to avoid food waste, on the probability of selecting a yoghurt drink with the shortest shelf life

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Noticing the message labels

Finally, it could be the case that the message interventions were ineffective in reducing the extent to

which participants engage in date labelling selection behavior, because the messages were only effective

for participants that actually noticed the message labels stuck onto the yoghurt drink packs in front of

the shelf. In the post-experiment questionnaire, participants were asked whether or not they had seen a

label on some of the packs of yoghurt drink. In total, 58 out of the 72 participants who were in fact

exposed to yoghurt drink packages with a message label recalled seeing a message label (72.2 percent).

It is predicted that the message interventions were more effective for participants who actually noticed

the message labels (versus all participants) when there were message labels to be noticed. Is the effect

of the messages stronger if we filter out the participants who should have seen message labels, but did

not see them? In order to test this, we repeated the initial, main analysis solely for participants who

indicated to have noticed the message labels, and tested the effect of the message conditions against the

‘no message’ control condition which still included all participants. The analysis revealed that the

effects of the messages were slightly stronger (compared to the initial main analysis) but still did not

reach significance (Wald χ² (3) = .366, p = .947). The model results can be found in Appendix 6C and

are also graphically visualized in Figure 10 below.

Figure 10 – Graphical visualization of the effect of type of message, for all participants and for solely the participants who noticed the message labels, on the probability of selecting a yoghurt drink with the shortest shelf life.

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3.5 – Preliminary Conclusion

The study showed that ‘type of message’ had an insignificant effect on whether or not participants

engaged in date labelling selection behaviour. In order to better understand why the message

interventions were ineffective, several follow-up analyses were performed with 1) the time until expiry,

2) participants’ a priori intention to avoid food waste, and 3) the extent to which participants noticed

the message labels. However, none of these follow-up analyses showed significant effects which is most

likely due to the relatively low sample size of this second study and subsequent power problems.

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39

Conclusions and Recommendations

4.1 – General conclusion and discussion

A substantial amount of food produced for human consumption is wasted nowadays, which entails

negative economic, environmental and ethical consequences. This research revolved around the

supposition that, with respect to limited shelf life food products, consumers engage in date labelling

selection behaviour in retail stores which in turn contributes to food waste. However, up to this point,

it was not empirically studied how big the proportion of consumers exactly is that have the tendency to

select food items with a longer or the longest shelf life, why consumers have the tendency to do so,

when consumers are more/less inclined to do so, what retailers could subsequently do about it etcetera.

In order to provide answers to these questions, two experimental studies were conducted.

With respect to the extent to which consumers engage in selection behaviour (the first research

question), it can be concluded from Study 1 that almost two-thirds (64.3 percent) engaged in date

labelling selection behaviour when selecting a limited shelf life yoghurt product from the shelf. This

finding is in line with existing literature suggesting that consumer’s date labelling selection behaviour

is omnipresent and therefore problematic. In Study 2, in which Tilburg University students participated,

54.1 percent engaged in date labelling selection behaviour. A possible explanation for this lower

percentage could be, as also became clear from consumer profiling in Study 1, that higher educated and

younger consumers are less likely to engage in date labelling selection behaviour.

As expected, almost all consumers that engaged in date labelling selection behaviour deliberately and

consciously did so. Interestingly, it can be concluded that the most prominent reason for consumers as

why to (deliberately) engage in date labelling selection behaviour (the second research question) is

because a yoghurt pack with a longer remaining shelf life would provide more time for consumption

and therefore more flexibility. In other words, it became clear that the ‘more flexibility’ motive

underlying date labelling selection behaviour is by far the most important motive for consumers to

engage in such selection behaviour. Somewhat surprisingly, the ‘higher quality’ motive turned out to

be most important for only 10 percent of the consumers that engaged in selection behaviour.

Furthermore, the majority of consumers that did not engage in date labelling selection behaviour also

deliberately and consciously did so, while it was predicted that this behavioural act would mainly be

automatic and unconscious since this is the norm-consistent way. It could be, however, that we have

turned this behavioural act in more deliberate and conscious behaviour than it in reality is. By asking

consumers whether their choice was deliberate or not, these consumers might started to think about

their own behaviour more than they would normally do. Yet, only very few consumers reported to

deliberately select the first food item in order to avoid food waste. It could be that consumers are

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unaware of the fact that date labelling selection behaviour contributes to food waste, or that consumers

simply do not care enough about food waste. A more important motive for consumers not to engage in

date labelling selection behaviour is related to the argument that they still have sufficient time for

consumption. Only a few participants reasoned that the food item in front of the shelf will taste as good

as food items further on the back of the shelf.

Various situations and circumstances were assessed in this research in order to identify when consumers

are more/less likely to engage in date labelling selection behaviour (the third research question).

Noteworthy, only a few situations and circumstances were examined that could potentially impact the

effectiveness of retailer interventions, but there is much more to discover. To start, it can be concluded

that consumers are less likely to engage in date labelling selection behaviour when they have the

intention to consume the food on the same day as the day on which the food item is purchased. In that

situation, the need for flexibility is in a sense eliminated thereby lowering the tendency to select food

items with a longer expiration date. Furthermore, it appeared that consumers are also less likely to

engage in date labelling selection behaviour when they are higher educated, have a higher net monthly

household income, when they have a bigger household, and when they are aged 15 to 24. In addition,

it was examined whether consumers are more likely to engage in date labelling selection behaviour over

time when food items start to approach their date mark, whether consumers with high intention to avoid

food waste are less likely to engage in date labelling selection behaviour, and whether consumers that

are actually aware of the retailer interventions are less likely to engage in date labelling selection

behaviour. However, as will be explained in more detail below, none of these effects reached

significance.

With respect to what the retailer could do to successfully intervene with date labelling selection

behaviour (the fourth research question), Study 2 examined whether message interventions that

challenge the underlying motives for selection behaviour (by means of labels attached to food items in

front of the shelf with the shortest shelf life) were effective in attenuating the extent to which consumers

engage in this behaviour. Unfortunately, this first attempt at finding a solution turned out to be

ineffective. Both hypotheses with respect to the message interventions were therefore rejected; it could

not be concluded that (1) consumers that are exposed to a message that challenges an underlying

motivation for date labelling selection behaviour are less likely to engage in such selection behaviour

than consumers that are not exposed to such a message, and that (2) consumers that are exposed to the

flexibility-related message are less likely to engage in date labelling selection behaviour than consumers

that are exposed to the quality-related message. In an attempt to understand why the message

interventions were ineffective (i.e. did not have a significant effect on the extent to which consumers

engage in selection behaviour), several follow-up analyses were conducted. Potential situations were

assessed in which consumers could in general be more/less inclined to engage in date labelling selection

behaviour (therefore relating to the third research question). Unfortunately, none of the identified

41

potential moderators (time until expiry, participants’ a priori intention to avoid food waste, and the

extent to which participants noticed the message labels) turned out to have a significant effect on the

relationship between the message interventions and selection behaviour, which may be due to power

problems. Although none of the effects reached significance, some interesting patterns were detected

in line with what was expected; a negative time trend was observed, consumers that have high intention

to avoid food waste are slightly more inclined to engage less in date labelling selection behaviour in the

presence of the flexibility-related or the quality-related message, and the messages seem to have a

slightly stronger effect on the consumers who actually noticed the message labels when message labels

were present. To end, a possible reason of why the flexibility-related message turned out to be

ineffective could be related to the persistence of the ‘more flexibility’ consumer motive underlying date

labelling selection behaviour. It became apparent from Study 1 that the ‘more flexibility’ motive is a

hard to disempower motive. So while the ‘more flexibility’ motive is valuable to focus upon with respect

to retailer interventions since this motive is for many consumers the most prominent reason as why to

engage in date labelling selection behaviour, it is at the same time a difficult to disempower motive.

4.2 – Recommendations

What do the findings mentioned above imply, and which recommendations can be derived from this?

First of all, it is recommended to take consumer’s date labelling selection behaviour in retail stores and

its contribution to food waste seriously. This research showed that many consumers opt for and

eventually buy food items with a longer/ the longest remaining shelf life with respect to limited shelf

life food products. Therefore, date labelling selection behaviour is something to consider in the battle

against food waste. By reducing the number of consumers that engage in date labelling selection

behaviour, less food items will turn into food waste in retail stores. Unfortunately, the first attempt in

Study 2 to successfully intervene with consumer’s date labelling selection behaviour failed; the labels

with various messages aimed to weaken consumer motives underlying date labelling selection

behaviour did not have the intended negative effect. All in all, it is recommended to first find an effective

retailer intervention before implementing anything, so further research is necessary.

4.3 – Limitations and suggestions for further research

First of all, a limitation of the follow-up analyses in Study 2 had to do with sample size. Although Study

2 only represented a first attempt at finding an effective solution against date labelling selection

behaviour, the follow-up analyses were underpowered because of this relatively small sample size. It is

plausible that the three identified moderators did not have a significant effect on the relationship

42

between the messages and the extent to which consumers engaged in date labelling selection behaviour

because the analyses were underpowered. Therefore, as a suggestion for further research, one could re-

investigate the observed trends of (1) time until expiry, (2) participants’ a priori intention to avoid food

waste, and (3) the extent to which participants noticed the message labels. By doing so, we might be

better able to understand why the message interventions were ineffective in reducing date labelling

selection behaviour. Besides, the better we understand in which situations or circumstances consumers

are more/less inclined to engage in date labelling selection behaviour, the better we can judge whether

other potential retailer interventions will be effective in attenuating the extent to which consumers

engage in selection behaviour. Therefore, it is also suggested to identify and examine more situations

and/or circumstances in which consumers are more/less likely to engage in selection behaviour.

Furthermore, since Study 2 was only a first attempt at finding a solution against consumer’s date

labelling selection behaviour, a suggestion for further research would be to investigate other types of

(message) interventions. The solution to date labelling selection behaviour could also (partially) lie in

creating more awareness about the effect date labelling selection behaviour has on food waste in retail

stores, while at the same time intervening with message labels. In addition, it is often argued that

consumers do consider suboptimal food (i.e. food with the shortest shelf life) when offered at a discount

(Aschemann-Witzel et al., 2015). Therefore, it could be further researched whether this would

successfully reduce date labelling selection behaviour while at the same time being feasible in terms of

money for retailers. As a final remark, another suggestion for future research could be to re-examine

the message label interventions in a study that does not solely contain students as participants.

43

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47

Appendix 1 – Questionnaire Study 1 Vragenlijst “Boodschappen doen in de supermarkt”

Respondenten willekeurig toewijzen aan één van twee condities:

Instructie = 1 (meteen opeten); (condition 2)

Instructie = 2 (onzekerheid) (condition 1)

Scherm 1:

Deze vragenlijst gaat over boodschappen doen. We zijn benieuwd naar hoe u bepaalde keuzes maakt in de supermarkt. Er zijn geen goede of foute antwoorden.

Scherm 2:

Zo meteen krijgt u een foto te zien van een supermarktschap met pakken yoghurt.

Als Instructie = 1: Stelt u zich voor dat u een toetje gaat maken voor vanavond waarvoor u 500 ml yoghurt nodig hebt. U bent in de supermarkt om onder andere een pak yoghurt te kopen.

Als Instructie = 2: Stelt u zich voor dat u boodschappen aan het doen bent in de supermarkt. U hebt een boodschappenlijstje, maar kijkt daarnaast ook gewoon een beetje rond voor andere dingen. Omdat u ’s ochtends wel eens trek hebt in yoghurt, besluit u een pak yoghurt in huis te halen.

Voor het slagen van dit onderzoek is het van belang dat u zich voorstelt dat het vandaag 3 maart is.

Scherm 3:

Q1. Als u van plan zou zijn een pak yoghurt te kopen [Indien Instructie = 1: voor het toetje voor vanavond], welke van deze pakken zou u dan nemen? De pakken zijn genummerd van 1 tot en met 7. Selecteer hieronder het nummer van het pak dat u zou nemen.

1 2 3 4 5 6 7

48

Scherm 4:

Indien Q1 = 1 OF 2:

Q2. Er stonden pakken yoghurt met een houdbaarheidsdatum van 17 maart in het schap. Hebt u expres gekozen voor een pak met een houdbaarheidsdatum van 15 maart?

1 Nee, ik heb gewoon een pak dat vooraan stond gekozen

2 Ja, ik heb expres voor een pak yoghurt met een kortere houdbaarheid gekozen

Scherm 5:

Indien Q1 = 1 OF 2 en Q2 = 2:

Q3. Waarom koos u expres voor een pak met een kortere houdbaarheid?

Kies het antwoord dat het meest voor u geldt.

1 De yoghurt is nog zeker 12 dagen houdbaar, wat me genoeg tijd zou geven om de yoghurt op te eten

2 Ik verwacht dat de yoghurt even goed smaakt als de yoghurt met een langere houdbaarheid

3 Ik zou het zonde vinden als pakken met een kortere houdbaarheidsdatum uiteindelijk weggegooid zouden moeten worden

4 Anders, namelijk …

Scherm 4:

Indien Q1 = 3, 4, 5, 6 OF 7:

Q2. Er stonden pakken yoghurt met een houdbaarheidsdatum van 15 maart in het schap. Hebt u expres gekozen voor een pak met een houdbaarheidsdatum van 17 maart?

1 Nee, ik heb zo maar een pak gekozen

2 Ja, ik heb expres voor een pak yoghurt met een langere houdbaarheid gekozen

Scherm 5:

Indien Q1 = 3, 4, 5, 6 OF 7 en Q2 = 2:

Q3. Waarom koos u expres voor een pak met een langere houdbaarheid?

Kies het antwoord dat het meest voor u geldt.

1 Het geeft me meer tijd om de yoghurt op te eten voor het over de datum gaat

2 Ik verwacht dat de yoghurt beter smaakt dan de yoghurt met een kortere houdbaarheid omdat het iets verser is

3 Anders, namelijk …

49

Appendix 2 – Results Study 1

• With Y = ‘engaging in date labelling selection behaviour’

Block 1: Method = Enter

Omnibus Tests of Model Coefficients

Chi-square df Sig.

Step 1 Step 71,809 1 ,000

Block 71,809 1 ,000

Model 71,809 1 ,000

Model Summary

Step -2 Log likelihood

Cox & Snell R

Square

Nagelkerke R

Square

1 2711,033a ,035 ,047

a. Estimation terminated at iteration number 3 because parameter

estimates changed by less than ,001.

Classification Tablea

Observed

Predicted Datum_Duiken Percentage

Correct 0 1

Step 1 Datum_Duiken 0 537 370 59,2

1 450 666 59,7

Overall Percentage 59,5

a. The cut value is ,500

Variables in the Equation

B S.E. Wald df Sig. Exp(B)

Step 1a conditie ,765 ,091 70,520 1 ,000 2,148

Constant -,941 ,143 43,132 1 ,000 ,390

a. Variable(s) entered on step 1: conditie.

50

• With Y = ‘high flexibility motive’

Block 1: Method = Enter

Omnibus Tests of Model Coefficients

Chi-square df Sig.

Step 1 Step 18,219 1 ,000

Block 18,219 1 ,000

Model 18,219 1 ,000

Model Summary

Step -2 Log likelihood

Cox & Snell R

Square

Nagelkerke R

Square

1 744,973a ,017 ,033

a. Estimation terminated at iteration number 5 because parameter

estimates changed by less than ,001.

Classification Tablea

Observed

Predicted FLEX Percentage

Correct 0 1

Step 1 FLEX 0 0 122 ,0

1 0 964 100,0

Overall Percentage 88,8

a. The cut value is ,500

Variables in the Equation

B S.E. Wald df Sig. Exp(B)

Step 1a conditie ,826 ,195 17,916 1 ,000 2,285

Constant ,811 ,298 7,426 1 ,006 2,250

a. Variable(s) entered on step 1: conditie.

51

Appendix 3 – Instruction Study 2

52

53

Appendix 4 – Post-Experiment Questionnaire Study 2

54

55

Appendix 5 – Results Study 2

• Reference category: ‘no message’

Categorical Variables Codings

Frequency

Parameter coding

(1) (2) (3)

Conditie 0 (geen sticker 24 ,000 ,000 ,000

1 (pak mij) 24 1,000 ,000 ,000

2 (pak mij, flexibiliteit) 24 ,000 1,000 ,000

3 (pak mij, kwaliteit) 24 ,000 ,000 1,000

Block 1: Method = Enter

Omnibus Tests of Model Coefficients

Chi-square df Sig.

Step 1 Step ,501 3 ,919

Block ,501 3 ,919

Model ,501 3 ,919

Model Summary

Step -2 Log likelihood

Cox & Snell R

Square

Nagelkerke R

Square

1 132,417a ,005 ,007

a. Estimation terminated at iteration number 2 because parameter

estimates changed by less than ,001.

Classification Tablea

Observed

Predicted Oudste_datum_pak_Y

Percentage Correct 0 1

Step 1 Oudste_datum_pak_Y 0 39 11 78,0

1 33 13 28,3

Overall Percentage 54,2

a. The cut value is ,500

56

Variables in the Equation

B S.E. Wald df Sig. Exp(B)

Step 1a Conditie ,499 3 ,919

Conditie(1) ,000 ,579 ,000 1 1,000 1,000

Conditie(2) ,000 ,579 ,000 1 1,000 1,000

Conditie(3) ,334 ,579 ,333 1 ,564 1,397

Constant -,167 ,410 ,166 1 ,683 ,846

a. Variable(s) entered on step 1: Conditie.

• Reference category: ‘quality-related message’

Categorical Variables Codings

Frequency

Parameter coding

(1) (2) (3)

Conditie 0 (geen sticker 24 1,000 ,000 ,000

1 (pak mij) 24 ,000 1,000 ,000

2 (pak mij, flexibiliteit) 24 ,000 ,000 1,000

3 (pak mij, kwaliteit) 24 ,000 ,000 ,000

Block 1: Method = Enter

Omnibus Tests of Model Coefficients

Chi-square df Sig.

Step 1 Step ,501 3 ,919

Block ,501 3 ,919

Model ,501 3 ,919

Model Summary

Step -2 Log likelihood

Cox & Snell R

Square

Nagelkerke R

Square

1 132,417a ,005 ,007

a. Estimation terminated at iteration number 2 because parameter

estimates changed by less than ,001.

57

Classification Tablea

Observed

Predicted Oudste_datum_pak_Y

Percentage Correct 0 1

Step 1 Oudste_datum_pak_Y 0 39 11 78,0

1 33 13 28,3

Overall Percentage 54,2

a. The cut value is ,500

Variables in the Equation

B S.E. Wald df Sig. Exp(B)

Step 1a Conditie ,499 3 ,919

Conditie(1) -,334 ,579 ,333 1 ,564 ,716

Conditie(2) -,334 ,579 ,333 1 ,564 ,716

Conditie(3) -,334 ,579 ,333 1 ,564 ,716

Constant ,167 ,410 ,166 1 ,683 1,182

a. Variable(s) entered on step 1: Conditie.

58

59

Appendix 6A – Follow-up Analysis Study 2 with ‘time’

Categorical Variables Codings

Frequency

Parameter coding

(1) (2) (3)

Conditie 0 (geen sticker 24 ,000 ,000 ,000

1 (pak mij) 24 1,000 ,000 ,000

2 (pak mij, flexibiliteit) 24 ,000 1,000 ,000

3 (pak mij, kwaliteit) 24 ,000 ,000 1,000

Block 1: Method = Enter

Omnibus Tests of Model Coefficients

Chi-square df Sig.

Step 1 Step 7,761 11 ,735

Block 7,761 11 ,735

Model 7,761 11 ,735

Model Summary

Step -2 Log likelihood

Cox & Snell R

Square

Nagelkerke R

Square

1 125,156a ,078 ,104

a. Estimation terminated at iteration number 4 because parameter

estimates changed by less than ,001.

Classification Tablea

Observed

Predicted Oudste_datum_pak_Y Percentage

Correct 0 1

Step 1 Oudste_datum_pak_Y 0 31 19 62,0

1 18 28 60,9

Overall Percentage 61,5

a. The cut value is ,500

60

Variables in the Equation

B S.E. Wald df Sig. Exp(B)

Step 1a Conditie 1,509 3 ,680

Conditie(1) ,886 ,860 1,061 1 ,303 2,426

Conditie(2) ,892 ,862 1,071 1 ,301 2,440

Conditie(3) ,844 ,847 ,995 1 ,319 2,327

Dag_MC -,239 ,334 ,514 1 ,473 ,787

Conditie * Dag_MC 1,789 3 ,617

Conditie(1) by Dag_MC ,349 ,436 ,642 1 ,423 1,418

Conditie(2) by Dag_MC -,290 ,531 ,297 1 ,585 ,748

Conditie(3) by Dag_MC ,048 ,441 ,012 1 ,913 1,049

Dag2 ,221 ,193 1,306 1 ,253 1,247

Conditie * Dag2 2,253 3 ,522

Conditie(1) by Dag2 -,252 ,252 1,000 1 ,317 ,777

Conditie(2) by Dag2 -,418 ,288 2,103 1 ,147 ,659

Conditie(3) by Dag2 -,167 ,253 ,436 1 ,509 ,846

Constant -,903 ,628 2,071 1 ,150 ,405

a. Variable(s) entered on step 1: Conditie, Dag_MC, Conditie * Dag_MC , Dag2, Conditie * Dag2 .

Variables in the Equation

B S.E. Wald df Sig. Exp(B)

Step 1a D2 ,886 ,860 1,061 1 ,303 2,426

D3 ,892 ,862 1,071 1 ,301 2,440

D4 ,844 ,847 ,995 1 ,319 2,327

D1XDag_MC -,239 ,334 ,514 1 ,473 ,787

D2XDag_MC ,110 ,281 ,154 1 ,695 1,116

D3XDag_MC -,529 ,414 1,637 1 ,201 ,589

D4XDag_MC -,191 ,288 ,440 1 ,507 ,826

D1XDag2 ,221 ,193 1,306 1 ,253 1,247

D2XDag2 -,031 ,162 ,037 1 ,847 ,969

D3XDag2 -,197 ,213 ,849 1 ,357 ,822

D4XDag2 ,054 ,164 ,107 1 ,744 1,055

Constant -,903 ,628 2,071 1 ,150 ,405

a. Variable(s) entered on step 1: D2, D3, D4, D1XDag_MC, D2XDag_MC, D3XDag_MC, D4XDag_MC,

D1XDag2, D2XDag2, D3XDag2, D4XDag2.

61

Appendix 6B – Follow-up Analysis Study 2 with ‘intention to avoid food waste’

Categorical Variables Codings

Frequency

Parameter coding

(1) (2) (3)

Conditie 0 (geen sticker 24 ,000 ,000 ,000

1 (pak mij) 24 1,000 ,000 ,000

2 (pak mij, flexibiliteit) 24 ,000 1,000 ,000

3 (pak mij, kwaliteit) 24 ,000 ,000 1,000

Block 1: Method = Enter

Omnibus Tests of Model Coefficients

Chi-square df Sig.

Step 1 Step 5,646 7 ,582

Block 5,646 7 ,582

Model 5,646 7 ,582

Model Summary

Step -2 Log likelihood

Cox & Snell R

Square

Nagelkerke R

Square

1 127,271a ,057 ,076

a. Estimation terminated at iteration number 4 because parameter

estimates changed by less than ,001.

Classification Tablea

Observed

Predicted Oudste_datum_pak_Y Percentage

Correct 0 1

Step

1

Oudste_datum_pak_Y 0 37 13 74,0

1 23 23 50,0

Overall Percentage 62,5

a. The cut value is ,500

62

Variables in the Equation

B S.E. Wald df Sig. Exp(B)

Step 1a Conditie 3,921 3 ,270

Conditie(1) -2,822 2,417 1,363 1 ,243 ,059

Conditie(2) -5,899 3,136 3,539 1 ,060 ,003

Conditie(3) -3,246 2,460 1,742 1 ,187 ,039

Intention_to_avoid_food_waste -,489 ,322 2,300 1 ,129 ,614

Conditie *

Intention_to_avoid_food_waste 4,404 3 ,221

Conditie(1) by

Intention_to_avoid_food_waste ,533 ,444 1,437 1 ,231 1,704

Conditie(2) by

Intention_to_avoid_food_waste 1,085 ,556 3,805 1 ,051 2,959

Conditie(3) by

Intention_to_avoid_food_waste ,687 ,461 2,215 1 ,137 1,987

Constant 2,428 1,787 1,846 1 ,174 11,338

a. Variable(s) entered on step 1: Conditie, Intention_to_avoid_food_waste, Conditie *

Intention_to_avoid_food_waste .

Block 1: Method = Enter

Omnibus Tests of Model Coefficients

Chi-square df Sig.

Step 1 Step 4,767 7 ,688

Block 4,767 7 ,688

Model 4,767 7 ,688

Model Summary

Step -2 Log likelihood

Cox & Snell R

Square

Nagelkerke R

Square

1 128,151a ,048 ,065

a. Estimation terminated at iteration number 3 because parameter

estimates changed by less than ,001.

63

Classification Tablea

Observed

Predicted Oudste_datum_pak_Y

Percentage Correct 0 1

Step 1 Oudste_datum_pak_Y 0 25 25 50,0

1 14 32 69,6

Overall Percentage 59,4

a. The cut value is ,500

Variables in the Equation

B S.E. Wald df Sig. Exp(B)

Step 1a Intention_to_avoid_binary -1,386 ,894 2,402 1 ,121 ,250

D2XLow_intention -,693 ,886 ,611 1 ,434 ,500

D3XLow_intention -1,281 ,901 2,023 1 ,155 ,278

D4XLow_intention -,442 ,868 ,259 1 ,611 ,643

D2XHigh_intention ,288 ,847 ,115 1 ,734 1,333

D3XHigh_intention 1,099 ,847 1,684 1 ,194 3,000

D4XHigh_intention ,693 ,894 ,601 1 ,438 2,000

Constant ,000 ,447 ,000 1 1,000 1,000

a. Variable(s) entered on step 1: Intention_to_avoid_binary, D2XLow_intention, D3XLow_intention,

D4XLow_intention, D2XHigh_intention, D3XHigh_intention, D4XHigh_intention.

64

65

Appendix 6C – Follow-up Analysis Study 2 with ‘noticing the message labels’

• Main, initial analysis but with the following filter: IF Conditie=1 OR Conditie > 1 & Label_Awareness=1

Categorical Variables Codings

Frequency

Parameter coding

(1) (2) (3)

Conditie 0 (geen sticker 24 .000 .000 .000

1 (pak mij) 16 1.000 .000 .000

2 (pak mij, flexibiliteit) 22 .000 1.000 .000

3 (pak mij, kwaliteit) 20 .000 .000 1.000

Block 1: Method = Enter

Omnibus Tests of Model Coefficients

Chi-square df Sig.

Step 1 Step .367 3 .947

Block .367 3 .947

Model .367 3 .947

Model Summary

Step -2 Log likelihood

Cox & Snell R

Square

Nagelkerke R

Square

1 113.309a .004 .006

a. Estimation terminated at iteration number 3 because parameter

estimates changed by less than .001.

Classification Tablea

Observed

Predicted Oudste_datum_pak_Y Percentage

Correct 0 1

Step 1 Oudste_datum_pak_Y 0 13 28 31.7

1 11 30 73.2

Overall Percentage 52.4

a. The cut value is .500

66

Variables in the Equation

B S.E. Wald df Sig. Exp(B)

Step 1a Conditie .366 3 .947

Conditie(1) .167 .646 .067 1 .796 1.182

Conditie(2) .167 .591 .080 1 .778 1.182

Conditie(3) .368 .608 .366 1 .545 1.444

Constant -.167 .410 .166 1 .683 .846

a. Variable(s) entered on step 1: Conditie.