Session on adjusting for quality change 27 th Voorburg Group Meeting Warsaw, Poland André Loranger October 1, 2012

Session on adjusting for quality change

27th Voorburg Group MeetingWarsaw, Poland

André LorangerOctober 1, 2012

Goal of this session

This session is a continuation of last year’s discussion on quality change. The objective of the session are:1. Review the issues raised at last year’s meeting.

2. Present and discuss the paper and the outcome of the consultation with price experts.

3. Outline and discuss options for moving forward on quality adjustment issues.

23-04-21Statistics Canada • Statistique Canada2

Outstanding questions and recommendations, VG 2011

Advertising and Air Transport• Main question: Should consumer utility or changes to

the production function be the basis for the quality adjustment for SPPIs?

• Outcome and recommendations: The majority present supported the practice of only quality adjusting for changes in the production function while a minority supported considering consumer utility.


Outstanding questions and recommendations, VG 2011

Distributive Trades (wholesale and retail services)• Main question: Should the good being traded be quality adjusted

when adjusting the service?

• Outcome and recommendations: No consensus regarding whether quality adjustments should be made to the goods resold when calculating a margin price index. Countries should instead consult with their own SNA for direction.

The Ottawa Group on Price Statistics should be consulted on matters pertaining to quality adjustment


Consultation with CPI Experts

The Ottawa Group did not meet over the last year instead a paper summarizing the issues was written and presented at the UNECE-ILO meeting of the Group of Experts on Consumer Price Indices in Geneva, Switzerland this spring.• As part of the institutional review process, the paper

was reviewed was by several price experts including members of Statistics Canada’s Price Measurement Advisory Committee.


Summary of Geneva paper Provided background on PPIs, the Voorburg Group and

VG discussions on quality change Summarized the issues and discussion from VG 2011 for

Air Transport, Advertising and Distributive Trades Expanded arguments for the production function view VG 2012 version of the paper also discusses

recommendations from Geneva and a potential way forward for the VG


Expanding the arguments for the production function view

Utility curve example, achieved vs. expected audience size

Discrepancy between producer and consumer valuations of quality, aircraft seat example

Triplett argument for resource-cost view Distributive trades, QA for service or good or

both


Utility and production functions P is surface that traces out all

combinations of 2 characteristics Z1 and Z2

q is indifference curve that maps out all combinations of Z1 and Z2 that the consumer is indifferent against purchasing

S is production function (combination of inputs and technology

Service delivery occurs at A, the intersection of the optimal production and utility at a given price


Utility and production functions “Expected Audience” example

In Q1, • P = 1000

• Expected audience = 1 M

In Q2, • P = 1500,

• Expected Audience = 1 M

P = f(Expected Audience) Achieved Audience does not

factor into production or consumption decision, although it may lead to greater consumer utility

Don’t adjust for audience size, pure price effect


Utility and production functions“Achieved Audience” example

In Q1, • P = 1000, Achieved Audience = 1 M,

• PperAchievedViewer = 0.001

In Q2, • P = 1500, Achieved Audience = 1.5 M

• PperAchievedViewer = 0.001

P = f(Achieved Audience) Achieved Audience is a price

determining characteristic, therefore must adjust for quality

What is the appropriate basis for making the adjustment? Potential discrepancy between producer and user valuations.


Discrepancy between producer and consumer valuations of the QAAircraft seat example


Observed price (£)

SPPI

Quality adjust-

ment (£)

Quality Adjusted Price (£)

Price indexSPPI

Observed Turnover

(£)

Derived (constant

price) output

Change in

volume2009 140 140 100 5,000,000 5,000,000 -2010 126 14 140 100 5,250,000 5,250,000 5.0%

Observed price (£)

CPI

Quality adjust-ment (£)

Quality Adjusted Price (£)

Price indexCPI

Observed Consumer

Expenditure (£)

Derived (constant

price) expenditur

e

Change in

volume2009 140 140 100 5,000,000 5,000,000 -2010 126 28 154 110 5,250,000 4,772,727 -4.5%

Change in configuration of aircraft, increase number of seats (smaller), change in production function Leads to a decrease in operating costs and a decrease in price To deliver same level of quality, firm needs to increase price by 14 (QA) Leads to increase in volume

Consumers place more value on leg room than the QA estimated from the producer side. A QA of 28 is required to get back to same level of quality. Translates into a 10% increase in CPI Leads to decrease in volume

Air Transport, Additional thoughts

Unit value (Revenue per flight) is one of the recommended approaches for measuring price change in this industry

Production function approach to QA fits well with this model.• Quality change based on changes to inputs (seating

configuration, flight crew, etc., fuel, etc.)

• Fix quality of the flight, not the individual consumer.


Discrepancy between producer and consumer valuations of the QAAircraft seat example, continued


The supply-demand identity for a given product or service in the SNA is:

Supply = output + imports + transport margin + trade margin + taxes – subs. on products

=intermediate consumption + final consumption expenditure + gross capital formation

+ exports =Demand

Assuming that consumers purchase 100% of the output and that there are no margins or taxes, it follows that:

output = final consumption expenditure

Identity cannot be resolved in real terms if PPI and CPI are different

Additional thoughts From Jack Triplett, “Concepts of Quality in Input and Output Price

Measures. A Resolution of the User Value Resource-Cost Debate.”• There are two different uses of the data (input measures and output

measures) and that input and output price indexes imply different theoretical price index treatments.

• In a resource cost view, the cost of making a machine is the proper basis for making quality adjustments, not the productivity of using these machines to produce other goods.

“The principal conceptual basis for the output PPI is the fixed-input output price index (FIOPI). The output PPI thus aims to measure an output price index constructed on the assumption that inputs and technology are fixed.” PPI manual, 7.44

Resource-cost view is conceptually consistent with the Fixed-input output price index (FIOPI), therefore quality adjustment based on the production function would seem to be appropriate for SPPI


Wholesale and Retail ServicesQuality adjusting goods or service portion?

SNA output definition excludes the good• The recording in the SNA of transactions for wholesalers and retailers

does not mirror the way in which those involved view them. The purchases of goods for resale by wholesalers and retailers are not recorded by these units explicitly, and they are viewed as selling, not the goods, but the services of storing and displaying a selection of goods in convenient locations and making them easily available for customers. This partitioning measures output for traders by the value of the margins realized on goods they purchase for resale. (SNA 2008, 3.68)

If output definition excludes the good then QA should not be carried out on the underlying good.


Wholesale and Retail ServicesQuality adjusting goods or service portion?


Output + Trade Margin = Final Consumption

V 100 50 150P 10 (PPI) 5 (15-10) (Margin

Price)15 (CPI)

Q 10 10 10

Example: V = value, P= price, Q = quantity, V = P x Q 10 widgets produced by manufacturer and sold to a consumer by a wholesaler/retailer Produce price of widgets = $10 Final purchase price of widgets = $15

Example shows that margins are additive in terms of value and price The margins and margins prices are mark-ups on the output and output prices. They exclude the value of the good. Quality adjustment for the margin index should exclude any adjustment for good because the good is netted out of the margin calculation.

Recommendations from Geneva Interactions between various international groups are

seen as positive as they encourage dialogue and different perspectives• “It was found useful to exchange experiences on the approaches used

for SPPI and CPI. One example of an area where exchange of views would be useful is the different perspective on quality adjustment in PPIs based on production functions and technology and CPIs based on utility functions.”

Very little specific feedback was received from the Expert Group on CPI. Possible reasons include:• Complex topic

• Short discussion

• Paper and presentation not clear23-04-21Statistics Canada • Statistique Canada17

Way forward for VG Further work on this topic is required Dichotomy between producer view and consumer view Despite the arguments put forward here, for some

services, intuitively it seems reasonable to adjust for quality based on consumer utility rather than the production function.


Way forward for VG


Service (ISIC) Disposition of use (consumer

expenditure, intermediate use)

Approach (consumer utility

or production function)

Method

In deciding which approach is best, we need to consider how the service is consumed and by whom Basic proposal

• If consumption of output mainly by final consumer, adopt utility approach for QA• If consumption of output mainly intermediate use, adopt production function view• Incorporate the analysis and findings in sector paper to eventually cover all ISIC industries under VG mandate


Discussion

Documents

Session on adjusting for quality change 27 th Voorburg Group Meeting Warsaw, Poland André Loranger October 1, 2012