Ecological Economics 75 (2012) 52–60

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Ecological Economics

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Analysis

Voting for environmental donations: Experimental evidence from Majorca, Spain

Esther Blanco a,⁎, Maria Claudia Lopez b, Eric A. Coleman c

a Department of Public Finance, University of Innsbruck, Universitaetsstrasse 15/4, 6020 Innsbruck, Austriab Facultad de Estudios Ambientales y Rurales, Pontificia Universidad Javeriana, Transv.4° No. 42–00.Edificio J. Rafael Arboleda, S.J. Piso 8, Bogota, Colombiac Department of Political Science, Florida State University, 543 Bellamy, P.O. Box 3062230, Tallahassee, FL 32306–2230, United States

⁎ Corresponding author. Tel.: +43 5125077160; fax:E-mail addresses: esther.blanco@uibk.ac.at (E. Blanc

(M.C. Lopez), ecoleman@fsu.edu (E.A. Coleman).1 For a more detailed description of the Balearic Isl

analysis of the measure see Palmer and Riera (2003).

0921-8009/$ – see front matter © 2011 Elsevier B.V. Alldoi:10.1016/j.ecolecon.2011.12.014

a b s t r a c t

a r t i c l e i n f o

Article history:Received 7 May 2011Received in revised form 2 December 2011Accepted 19 December 2011Available online 20 January 2012

Keywords:Environmental fundraisingExperimentEcotaxTourism

This paper presents the results of a modified dictator game where donors are tourists in the island of Majorca,Spain, and the recipient is an environmental foundation. In this experiment we explore if the level of voluntarydonations varies under different treatments that include taxes (high and low levels) and voting treatments onchoosing and obligatory imposition of taxes (high vs. low and low vs. no tax). Our results show that partici-pants only self-imposemandatory contributionswhen theymust choose between a high or low tax, and rarelypassing the high tax. In addition, we find that those individuals who voted for a high tax and are in a groupwhere the majority votes for the low tax conform to their earlier vote by contributing more. Further, ourdata supports an incomplete crowding-out of voluntary donations by the application of tourism taxes ear-marked for environmental purposes. From a policy perspective, this result supports the potential for a comple-mentary use of taxes and voluntary donations for fundraising environmental projects in tourism destinations.

© 2011 Elsevier B.V. All rights reserved.

1. Introduction

Researchers and policy-makers invest substantial effort to analyze theeffects of indirect taxes on tourism activity (Bonham and Gangnes, 1996;Jensen andWanhill, 2002; Palmer et al., 2007). Advocates of indirect taxeson tourism argue that such taxes (i) raise revenue, (ii) cover the costs ofenvironmental public service provision, and (iii) act as a market correct-ing mechanism and provide incentives for tourists to internalize the ex-ternal costs of environmentally destructive activities (Gago et al., 2009).

In this paper we investigate, through an economic experiment,the effects of different tax institutions on the behavior of tourists inthe Balearic Islands, Spain. These Islands served more than 9 millioninternational tourists in 2010, which represents almost 1% of thetourism market worldwide (Conselleria de Turisme i Treball, 2011;UNWTO, 2011), and have one of the highest tourism rates per capitain the world, with 14 tourists for every citizen (Garín-Muñoz andMontero-Martín, 2007). Previous literature has paid attention tothe specific case of the Balearic Islands tourism ecotax (Aguilóet al., 2005; Garín-Muñoz, 2007; Garín-Muñoz and Montero-Martín, 2007; Gago et al., 2009; Palmer and Riera 2003). The ecotaxwas applied to overnight stays and was meant to raise money forfunding environmental projects on the island.1 The rationale of the

+43 5125072788.o), mlopez@javeriana.edu.co

ands ecotax and an economic

rights reserved.

ecotax was to make international tourists contribute to the mitiga-tion of the environmental problems derived from congestion. Theecotax raised almost 72 million euros in a two year implementationperiod (2002–2003). Despite the success in generating revenue, thetax was abolished after a different political party took control ofthe local government. The incoming government's platform revolvedaround the social and political unrest derived from the ecotax. Polit-ical responses to municipal hotel room taxes have also been ob-served in the Dominican Republic, Puerto Rico, Mexico, and othercountries (Gago et al., 2009).

Businesses are often concerned that such taxes might reduce tour-ist visits and thus negatively influence profits of the tourism industry.Based on their price-elasticity estimates of tourism demand to theSpanish archipelago, Aguiló et al. (2005) forecasted the effect of theecotax by estimating the effects of a 1 euro tax per person and perday in the Balearic Islands. They found that this would result in117,660 fewer tourists or a 1.44% decrease in the number of touristsfor the year 2000. Using data from 1991–2003 (thus including years2002–2003, when the ecotax was in place), Garín-Muñoz (2007)estimated a negative effect of the ecotax for German tourism demandto the Balearic Islands. However, Garín-Muñoz and Montero-Martín(2007) did not find a significant effect on the number of arrivalswhen considering all international tourism demand for this sameperiod. This latter finding is consistent with another study analyzingthe impact of the 5% Hawaii hotel room tax (which generated $82million of revenue in 1990, making it the third largest source ofState revenue) which did not find a statistically significant impacton visitors (Bonham and Gangnes, 1996).

53E. Blanco et al. / Ecological Economics 75 (2012) 52–60

After the Balearic Islands ecotax was abolished, a voluntary mech-anism to receive and promote voluntary donations to environmentalprojects by tourists was implemented. The voluntary donations didnot generate socio-political conflict as the ecotax did, but neitherdid they raise comparable revenues. The different fundraising capac-ity of the tax and voluntary initiatives could be the result of contextu-al differences for the years each measure was in place (e.g. differentenvironmental concerns) or because the institutional features ofsuch arrangements have fundamentally different fundraising capacityfrom tourism. In this paper we use an experimental research designmeant to control for the contextual differences that could accountfor differences in fundraising in institutional environments of volun-tary donations as compared to alternatives where a tax is imposed,or voted for, while still allowing for voluntary donations. In theBalearic Islands voluntary donations and taxes have been implemen-ted as mutually exclusive. Yet, in many other regions and domainsgovernments implement policies combining taxes with voluntary do-nations to public goods aiming to enhance total fundraising. 2 Ourgoal is to assess whether voluntary donations by tourists significantlydiffer when a tax is imposed, and if these differences can be narrowedif tourists are allowed to participate in the decision to establish thetaxing mechanism (through voting).

Andreoni (1990) shows that individuals are not indifferent be-tween paying for charitable goods voluntarily or through taxes (man-datory) and that when offered the choice, people will prefer to givevoluntarily since this entails higher warm glow. He experimentallyexplores the relevance of these concerns and finds an incompletecrowding-out effect. For the purpose of this paper we use the methoddeveloped by Andreoni (1990) to measure crowding out because hisexperimental setup is quite similar to our own.3 According to theauthor a perfect crowding-out situation is observed when averagecontributions after an imposed tax (voluntary and taxed contribu-tions) are the same as contributions previous to the tax. His results,as ours, showed highest total contributions from taxed groups thatthe authors interpret as an incomplete crowding-out.

In this paper we first investigate the effects on voluntary dona-tions of two different kinds of externally-imposed taxes — one lowand one high. We test whether each tax will crowd-out voluntary do-nations. Second, we include two treatments where participants areable to vote on the imposition of a tax. In the first treatment the par-ticipants decide whether to vote (by majority rule) for a compulsoryhigh tax or a low one; and, in the second treatment the participantsdecide whether to vote (again by majority rule) for a high tax or notax at all. We address whether the fundraising capacity of taxes varieswhen groups of tourists are offered the possibility to vote to imposemandatory donations by the group as compared with the situationwhere these taxes are exogenously imposed by the experimentalist.In particular we want to address the question of how endogenouschoice of rules (by voting) affects the level of contribution in a dona-tion setting. Particularly, the objective of the voting treatments is toexplore the implicit assumption in the political and tourism industryarena that tourist do not want to pay environmental taxes. Two of ourquestions of interest are whether (i) tourists would vote in favor of atax when having the opportunity to do so, and (ii) the voting processchanges donation patterns.

In doing so, we diverge from previous studies of the economic im-pact of the Balearic Islands ecotax, which were based on analyses of

2 An experimental design imposing a tax with perfect enforcement and not allowingsubjects to additionally consider a voluntary donation is trivial, as it would leave theparticipant without any decision task.

3 However, we acknowledge the existence of other methods to measure crowdingthat are found in the literature reviewed by Bowles (2008) and Bowles and PolaníaReyes (forthcoming). These authors review more than 50 social dilemma experiments,and find there are many different methods various authors have used to measurecrowding.

tourism demand. Instead we make use of a different methodologyby using economic experiments. The use of experiments in tourismstudies is very recent. To the best of our knowledge, only three papershave used experimental economics for studying issues related withtourism. Alpizar et al. (2008a) and (2008b) conduct natural experi-ments with international visitors to a Costa Rican National Park. Theauthors test first, the effect of information (anonymity and referencecontributions) on donations to the park, as well as the effect of reci-procity. Second, they analyze whether the effect of information ondonations varies when making a hypothetical choice in comparisonto a choice that involves an actual payment to the park. Their resultsshow that the difference between the two choices is significant andconsequently they conclude that research involving tourists as sub-ject pools should use actual payments rather than stated preferenceson willingness to pay. Lopez et al. (2011) explore different fundrais-ing mechanisms for environmental projects (including voluntary do-nations, taxes and matching instruments) but do not consider theeffect of allowing subjects to vote on the imposition of taxes. Their re-sults suggest that taxes generate imperfect crowding-out but match-ing instruments do not. Our paper contributes to this literature bycomparing voluntary donations to environmental projects in contextswhere taxes are self-imposed by participants.

In the economics literature the effects of voting have been exploredin different settings. Knox andMeinzen–Dick (1999) claim that throughvoting resource users communicate and generate commitment. Tyranand Feld (2006) report that contributions to a public good increasewhen the group votes for a specific rule compared to the case whenthe group faces an exogenous tax. They argue that voting provides a sig-nal of the value a subject places on the public good to the others in theexperiment. Sutter et al. (2010) explore in a public goods experimentthe effect of voting for the possibility of rewarding or punishing othergroupmembers. Their results support thatwhen the group has the pos-sibility to vote, there is a positive effect on cooperation levels comparedto a setting in which the same institutions have been determined exog-enously by the experimenter. This suggests that participation rights en-hance cooperation.

Our results show that participants in some cases passed the hightax when they have to decide between the high or the low tax. In ad-dition, we find that those individuals who voted for a high tax and arein a group where the majority of group members vote for the low taxconform to their earlier vote by contributing more. Further, our datasupports an incomplete crowding-out of voluntary donations by theapplication of tourism taxes ear-marked for environmental purposes.From a policy perspective, this result supports the potential for acomplementary use of taxes and voluntary donations for fundraisingenvironmental projects in tourism destinations.

2. Experimental Design

The research presented in this paper is based on a modifieddictator game. In our case, tourists participating in the experimentare the donors and the recipient is an environmental foundation,the Foundation for a Sustainable Development of the Balearics Islands(hereafter the FSB).4 Each participant was asked during the experi-ment to allocate the endowment they received between herself andthe recipient FSB.

In the experimental literature we found other papers using a dicta-tor game with a charity as the recipient (Eckel and Grossman, 1996;Eckel et al., 2007; Li et al., 2008; Munro and Valente, 2008). Eckel andGrossman (1996) make use of a double-anonymous dictator game to

4 The FSB is a public–private non-profit organization on charge of collecting the vol-untary donations (Green Card) that tourists and residents can buy in different placesaround the Islands (hotels, tourism information points, car rentals, natural protectedareas, etc.) to fund environmental projects.

Table 1Summary of participants in the different treatments.

No. of participants No. of groups

Baseline 46(16 university)(30 airport)

Low tax 30 (airport)

54 E. Blanco et al. / Ecological Economics 75 (2012) 52–60

explore charity donations by replacing the recipient with an estab-lished charitable organization (the American Red Cross). Findings inEckel and Grossman (1996, p.188) support that “altruistic behavior in-creases in dictator games when the recipient is a legitimate charity asopposed to an anonymous person who the subjects can infer isdrawn from the same population as themselves.” In a similar paperMunro and Valente (2008) substitute the recipient either by a pureor impure public good. These authors refer to the latter as privategoods bundled with a type of environmental offset or contribution toreduce environmental externalities. Their results show that partici-pants' decisions change significantly when offered impure publicgoods as opposed to pure public goods.

We conducted the experiments with international tourists at theIsland of Majorca. The experiments were conducted at the end ofthe summer of 2009 (end of the high tourism season) and were penand paper. The research project was described as a single decision-making task to last no more than 10 minutes, and where the partici-pant could have the opportunity to earn some money. In both casesparticipants traveling together were allowed to participate; however,participants were not allowed to show their forms to others or to co-ordinate their actions in any other way.

Subjects were also told that participation was voluntary; thus,they were free to walk away at any point but in doing so theywould not make any money. Decisions were private and anonymous.After the decision were made, the participants were handed twoenvelopes with an identification number, one envelope with theirearnings was theirs to keep and the second envelope containedtheir contributions to the FSB. Participants were asked to verify thatthe amount of money in both envelopes was correct and then the re-searchers sealed the envelope for the FSB. Additionally, subjects wereasked to fill a survey with socio-economic information regarding theirexperience as a tourist on the island and environmental preferencesquestions. We did not ask for any contact information because inthe pilots that appeared to be a major concern before agreeing to par-ticipate. At the conclusion of all experiments the total donations weregiven to the FSB. Participants were told their number and were giveninstructions on how to contact the FSB to confirm that a donationunder their participant number was received.5

The experimental design includes five different treatments, allbased on a modified dictator game. The instructions included a de-scription of the mission and main objectives of the FSB, an explana-tion of the decision task, and an example illustrating the decisiontask (see Appendix A for the baseline instructions; the rest of instruc-tions are available upon request). In the first treatment, the baselinetreatment, each participant was endowed with 15 euros and wasasked to choose the amount of money she wanted to give to theFSB. 6 Her earnings would consist of the money she decided to keep(i.e. the portion of the 15 euros she was not giving to the FSB).

The next two treatments test the effects of external taxes. The sec-ond treatment is a low tax treatment. Each participant was endowedwith 15 euros, but she was told that 5 euros of this amount was givencompulsorily to the FSB. Then, she received 10 euros and had to de-cide what to do with these remaining 10 euros. The third treatment,the high tax treatment, was very similar to the low tax treatment,but in this case 10 euros out the initial 15 euros were compulsorilygiven to the FSB. She received 5 euros and her decision was to decidewhether and how much to give from these remaining 5 euros.

The next two treatments investigate the effects of self-imposedtaxes. The fourth treatment was the vote low tax treatment. Partici-pants were assigned to a group of five people. Participants neverknew the identity of the other members of their group. Each partici-pant in the group started with 15 euros and was asked to make two

5 According to the FSB, no participant contacted them to verify that a donation wasmade under their participant number.

6 At the time of the experiment 1 euro was equivalent to US$1.47.

decisions. The first decision was to anonymously vote on whether tohave a compulsory allocation of 5 euros from every member of thegroup to give to the FSB. If at least 3 members of the group votedyes then it became compulsory that each group member had to give5 euros from their 15 euros to the FSB. Depending on voting results,participants for the second decision ended up playing either the base-line treatment (if less than three votes were yes) or the low tax treat-ment (if more than three votes were yes).

In the fifth and last treatment, the vote low/high tax treatmentparticipants were also assigned to play in a group of five. Each partic-ipant was endowed 15 euros. As in the previous treatment, each indi-vidual was asked to make two decisions. The first decision was toanonymously vote on whether to have a compulsory allocation of5 euros or a compulsory allocation of 10 euros from every memberof the group to give to the FSB. The allocation with at least threevotes was then selected for the second task of the treatment. If atleast 3 members of the group voted for low, then it became compul-sory that each group member had to give 5 euros from their15 euros to the FSB (playing the low treatment), but if at least 3 mem-bers of the group voted for high, then it became compulsory that eachgroup member had to give 10 euros from their 15 euros to the FSB(playing the high treatment). A summary of the participants andgroups in each treatment is provided in Table 1.

3. Recruitment

The recruitment of tourists to participate in this artifactural fieldexperiment proved to be more complex that we initially expected.We initially approached potential participants while they enjoyedtheir leisure time on vacation (detailed description below); however,this process was largely unsuccessful. Instead, we split recruitmentinto different processes: (i) with tourists at airport gates; (ii) withnon-vacationer tourists while doing leisure activities.

Initially the experiments were to be conducted in a hotel, in the areaof Magaluf in Majorca. The hotel had about more than 750 rooms, im-plying a potential number of approximately 1500 adult customers.The hotel agreed to send invitations to hotel guests inviting their partic-ipation in a decision-making activity. Guestswilling to participate in theexperiments were asked to sign in at the hotel front desk in advance.The experiments were to take place at 6 pm, which according to thehotel employees was the time of day when hotel guests were not likelyto be engaged in activities. The first day no customer volunteered toparticipate, the second day, only one customer was willing to partici-pate, and on the third day, again nobody showed up. We decided thento change the strategy and to distribute flyers inviting guests in diningareas, swimming-pool areas, and even in the beach next to the hotel.This alternative also proved unsatisfactory. We next went to the beachdirectly with the decision-making folders and tried to recruit partici-pants for doing the activity at the beach itself. This alternative wasalso inadequate to meet our enrollment goals.

At this point we decided to split the recruitment process into the twostrategies enunciated above. First, we recruited participants at the depar-ture gates of Palma de Majorca Airport, which is a common practice for

High tax 28 (airport)Vote low tax 20 (university) 4Vote high/low tax 20 (university) 4

Notes: Only the voting treatments were done in groups.

55E. Blanco et al. / Ecological Economics 75 (2012) 52–60

data collection in studies of tourism demand in Spain. We were advisedto limit participation time; thus, we decided not to conduct the votingtreatments at this location. We obtained all the required permits to ac-cess the departure gates for research purposes. The three researchersconducting the experiments at the airport were wearing a t-shirt fromthe University of the Balearics Islands and a formal identification with apicture provided and signed by the airport authorities. At the airportgates, we were finally able to run the baseline and the low and hightax treatments. Anecdotally, the participation rate was very low at theairport, resulting in a total of 88 participants after 3 days of recruitmentin an airport with an average of about 42500 passengers per day on Sep-tember 2009 (Conselleria de Turisme i Treball, 2011).

Because the voting treatmentswere impossible to conduct at the air-port, we recruited non-vacationer tourists through the University of theBalearic Islands. These participantswere tourists inMajorcawhosemaintravel purpose was taking some academic courses during their stay inthe island. We approached them while on a daylong excursion orga-nized by the University of the Balearic Islands as a welcoming activity.Participation rates among this subject pool were much higher, butsince the subject pool was small, the number of participants in the vot-ing treatments was limited to 56 participants.

In total 174 tourists participated in our experiments. The recruit-ment process differs according to the location where the experimentwas conducted. At the airport, each tourist, after being seated in hisdeparture gate, was approached by one of the members of the re-search team and asked to participate in a research project about envi-ronmental policy. In the University recruitment, the participants wereeither seated on a train or at the train station, when they were invitedto participate. The same protocols were followed both at the airportgates and at the University.

4. Results

Table 2 shows the summary statistics by the various treatmentconditions, the location of the experiment sessions, and a summarytotal for just the baseline condition and across all treatment condi-tions in both locations. See Appendix B for a detailed table describingeach variable reported in Table 2.

We first focus on the summary results of total and voluntary con-tributions across treatment conditions. Total contribution to the FSBconsists of the sum of the tax (if a tax is imposed) and voluntary con-tributions. The maximum voluntary contribution to the FSB variesdepending on the treatment the subject was participating in. In thebaseline and vote low treatments, potential earnings are the highest

Table 2Summary statistics by treatment condition.

Location Airport Unive

Treatment condition Base High tax Low tax Base

Total contribution 10.533 14.036 12.500 2.625(5.22) (1.90) (2.87) (2.75

Voluntary contribution 10.533 4.036 7.400 2.625(5.22) (1.90) (2.88) (2.75

Student experiments 0.000 0.000 0.000 1.000(0.00) (0.00) (0.00) (0.00

Trip Experience 33.767 34.357 35.233 35.37(7.23) (6.66) (4.98) (10.2

Environmentalism 1.667 1.393 1.433 1.625(0.99) (1.13) (1.30) (0.81

Number of visits 9.069 8.964 10.667 1.133(12.12) (11.75) (22.30) (0.52

Age 2.633 2.143 2.767 1.000(0.96) (1.11) (1.19) (0.00

Education 4.667 4.464 4.333 4.667(0.66) (0.92) (0.92) (0.72

Eurozone country 0.310 0.250 0.300 0.800(0.47) (0.44) (0.47) (0.41

Observations 30 28 30 16

(in the case the vote does not pass), with a maximum of 15 euros.In the low tax treatment the maximum earnings were 10 euros; and5 euros in the high tax, and low/high tax vote treatments (when thehigh tax is passed). The average earning (15 minus the total contribu-tions) across all treatments and locations was 5.51 euros, with maxi-mum earnings of 15 euros and a minimum of 0 euros.

Among the non-voting treatments, the baseline treatment has thelowest total contribution levels. This is the case despite the fact thatparticipants were contributing more than half of their endowmentacross both locations. The average total contributions across all ses-sions in the baseline condition is 7.78 euros (out of 15 euros initiallyendowed), while the average baseline contributions for the universitysubjects were just 2.63 euros and the average baseline contributionsfor the airport subjects were 4 times higher at 10.53 euros. The resultsfrom the baseline treatment are perhaps the most straightforward tocompare with the general literature on dictator games. Our donationlevels for the baseline treatment at the airport (University activity)are higher (lower) than those reported in previous literature oncharity donations. In a meta-analysis of dictator games Engel (2011)reviewed 616 variations on dictator games and found that, dictatorson average give 28.35% of their endowment. The contributions ofour sample, across both locations, are higher than the average hefound, but within the range of values reported in the studies. The re-sults from the baseline treatment in the sessions conducted at theuniversity show that subjects gave only 2.63 out of 15 euros, or 18%of their endowment, which is more in line with Engel's (2011) re-view. Subjects in the airport, however, gave 10.53 out of 15 euros,or 70% of their endowment to the FSB, which is a very large percent-age compared to the previous literature. Eckel and Grossman (1996)find that subjects give 31% of their endowment to a charity (in thiscase the Red Cross), which is higher than their findings for a standarddictator game, where subjects give 10% of their endowment. Theauthors also find that the contribution level increases as the subjectsconsider that the recipient deserves the donation. In other experi-ments by Li et al. (2008) the authors compare the voluntary givingto charities from the Government or private charities, finding thatthe average donations in the former case are 22% of endowmentand 27% for the private. These differences are motivated accordingto the authors by the cause that the charity is supporting, perceptionof effectiveness and efficiency, income and political affiliation.

We cannot ascertain the reason behind the difference in behaviorbetween the airport sample and the university students. The recruit-ment at the airport and at the university were as similar as possible,in the former case the tourists knew we were doing the research

rsity All locations

Vote high/low Vote low Base All treatments

9.150 3.000 7.783 9.507) (3.05) (2.88) (5.88) (5.33)

2.900 3.000 7.783 5.632) (3.23) (2.88) (5.88) (4.52)

1.000 1.000 0.348 0.389) (0.00) (0.00) (0.48) (0.49)5 27.850 25.450 34.326 32.3893) (12.53) (15.55) (8.32) (10.07)

1.850 1.600 1.652 1.576) (1.31) (1.27) (0.92) (1.15)

2.125 3.538 6.364 7.107) (2.31) (8.03) (10.49) (13.81)

1.000 1.067 2.089 2.000) (0.00) (0.26) (1.10) (1.15)

4.706 4.867 4.667 4.578) (0.77) (0.83) (0.67) (0.82)

0.588 0.467 0.477 0.403) (0.51) (0.52) (0.51) (0.49)

20 20 46 144

Table 3Linear regression estimates for voluntary contributions.

Airport University

(1) (2) (3) (4)

High tax dummy −6.498*** −5.955***(0.96) (0.97)

Low tax dummy −3.133*** −3.181***(0.94) (0.94)

Vote high/low tax dummy 0.275 −1.945*(1.00) (1.04)

Vote low tax dummy 0.375 −1.291(1.00) (1.13)

Trip experience −0.067 −0.270***(0.08) (0.10)

Environmentalism 0.532 1.322***(0.35) (0.44)

Number of visits −0.015 0.176*(0.03) (0.09)

Age 0.963** 1.873(0.42) (2.86)

Education −0.282 0.091(0.47) (0.54)

Eurozone country 0.334 0.099(0.86) (0.84)

Constant 10.533*** 10.804*** 2.625*** 7.772(0.66) (4.06) (0.74) (5.38)

R-Squared 0.352 0.438 0.003 0.396Adj. R-squared 0.336 0.380 −0.035 0.258F 23.045*** 7.507*** 0.074 2.865**N 88 86 56 44

Notes: Coefficients with standard errors in parentheses. Two-tailed hypothesis tests:*pb0.10, **pb0.05, ***pb0.01.

8 Missing data is a potential problem when introducing the control variables. As a ro-bustness check, regressions were ran to test treatment effects on only subjects with com-

56 E. Blanco et al. / Ecological Economics 75 (2012) 52–60

with the approval from the airport authorities, in the latter case theycould be certain we were interacting with them with the approval ofthe university and moreover that the university was organizing therecreational activity in which they were participating while we con-ducted the experiments. To our understanding these are the only dif-ferences in information we indirectly provide to participants, whichwas inherent to the approach method to the different samples of par-ticipants. As already mentioned, we had a very high rejection rate ofparticipating in the airport and very low rejection rate with universitystudents. As one referee suggested, it may be possible that only highlyaltruistic people on their time were willing to participate at the air-port, and that simultaneously they were also highly altruistic withtheir money. It could also be the case that the difference between ourtwo samples is mediated by the trust participants had in the team con-ducting the experiments. While we had an authorization from the air-port authorities, it is common understanding that tourists coming toMajorca are advised to be aware of swindlers. Moreover, some peopleaccepted to participate only after we mentioned that we were not col-lecting any contact information. However, the university studentswere aware that we were invited by the University to conduct this ac-tivity and this could influence their level of trust on the team of re-searchers. These different levels of trust could also explain highrejection rates in one setting and very low rejection rates in the other.Still another explanation could be that despite the fact that both sam-ples are composed of tourists; tourists while in vacation behave inher-ently different than tourists that also have other purposes for theirvisit, such as study. In addition, it could be that a social desirabilitybias was affecting donation levels for airport subjects but for a reason,this bias was weaker for university students. Finally as observed inTable 2, the groups do have some differences in terms of age, in termsof previous number of visits to Majorca, and in terms of the proportionthat came from a Eurozone country. The significant statistical differencebetween the number of visits in our two samples may imply that thesubjects at the airport may be more familiar with the environmentalneeds of the Island, and because of that they make contributions thatwere more generous than the subjects at the university. Engel (2011)finds that socio-economic characteristics such as age or gender influ-enced people behavior in a dictator game; these differences may ac-count for differences in baseline play between those at the universityand those at the airport as well. Specifically, Engel finds that older peo-ple give more than younger people and those who participated at theairport were much older than those at the university activity.

Comparing total contributions in the voting treatments and taxtreatments (with no voting) reveals that total contributions in the vot-ing treatments are substantially smaller thanwhen no voting is permit-ted (about 14 euros in the high tax vs. slightly more than 9 euros in thevote high/low tax treatment, and 12.5 euros in the low tax treatment vs.3 euros in the low tax treatment with voting). However, this appears tobe explained by differences in behavior, in general, between the ses-sions conducted at the university and those conducted at the airport.

We now turn to individual voting decisions in the treatments wherethe subject is allowed to vote on a group-imposed mandatory tax,7

which is our focus. In the high/low tax vote treatment, 75% of the partic-ipants vote for low tax and 25% vote for high tax. Group results from thevote indicate that four out of the five groups had amajority of theirmem-bers vote for the low tax. Thus, only one group playedwith high taxwhilethe other four playedwith low tax. On the other hand for the lowvote tax,75% of the participants vote for no tax (i.e. baseline) and 25% vote for lowtax. In this treatment none of the groups reached themajority rule to im-pose a low tax, and therefore all the groups played with baseline. At firstglance, the fact that voluntary contributions in the tax treatments are lowfollowing the vote (where 75% of subjects vote for the lowest tax) is con-sistent with the explanation that participants signal the fact that they did

7 In the case of voting for high or low, the experimenter imposed the tax, but thegroup had to decide the size of the tax.

not want to contribute to the FSB. Consider, for example, the low tax vote(where every group voted for zero tax and then played the baselinegame). Voluntary contributions in the low tax vote treatment were only3 euros, compared to 7.78 euros in the baseline game without a vote.However, this explanation is not sufficient because the subjects votingon the various tax rates were all participating in the university and theyhad lower baseline contributions than airport subjects.

To analyze our data more rigorously we separately analyze the datafrom the university and airport subjects and estimate two models foreach group, one controlling for background variables, and one modelwithout such controls. These models are presented in Table 3, wherewe report the results from ordinary least squares (OLS) regressionwhere the dependent variable of the models is voluntary contributionsto the FSB. Model 1 shows the effects of each treatment for the airportsubjects and Model 2 includes controls for those subjects. Model 3 re-ports the results for university subjects and Model 4 when controllingfor other variables.8 Coefficients of each variable are reported andtheir estimated standard errors are shown in parentheses.

From the first twomodels of Table 3 the estimated treatment effectsfrom the high tax and low tax treatments show a significant reductionin voluntary contributions. However, Models 3 and 4 show that thetreatment effects for the voting treatments are not significant, exceptafter including the controls. Regarding the controls in Models 2 and 4,the coefficient for trip experience is negative and statistically significantfor the University pool. The effect of environmentalism is positive andstrong in the student sample when separating out. Average environ-mentalism, however, is approximately the same across samples. Simi-larly, number of visits has a positive and significant (although at the10% level) on voluntary donations on the university sample. Age

plete data in order to insure that differences in results once controlling for other variableswas due to this control and not due to simply dropping some observations due tomissingdata. These ancillary regressions confirmed very similar results for the estimated treat-ment effects; these results are available from the authors upon request.

Fig. 1. Average individual contributions in the vote high/low tax treatment by individual (left panel) and group-aggregated (right panel) votes. The dark gray bar represents meanvoluntary contributions while the light gray bar represents mean mandatory contributions. The total height of the bar represents average total contributions. The number aboveeach bar is the average total contribution, while the number within each bar is the mean voluntary contribution. Therefore, the mean mandatory contributions are the differencebetween the number representing mean total contributions (top number of bar) and the number representing mean mandatory contributions (number in middle of bar). Numberof observations for each category are in parentheses next to label.

57E. Blanco et al. / Ecological Economics 75 (2012) 52–60

appears significant in the airport sample and those in that sample dotend to be quite older than the university subjects, so thismight accountfor some of the differences across the populations.9 Finally, there doesnot appear to be a strong Eurozone effect for either sample.

The treatment effects that do seem significant are the tax rates im-posed exogenously by the experimenter. In cases of external imposi-tion of taxes subjects give much fewer voluntary contributions.However, it is also the case that if subjects have the same preferencesover donations to the FSB then they might substitute their voluntarycontributions for mandatory contributions. Lopez et al. (2011) exam-ine this phenomenon and find that while subjects give fewer volun-tary contributions when there is a mandatory tax, such taxes do notcompletely crowd-out the voluntary contributions. This implies thatthere is higher fundraising capacity when taxes are coupled withthe opportunities to make voluntary donations compared to thecase where it is only possible to give voluntary donations alone.

Perhaps the most important insight from Table 3 is that while theexternal imposition of the environmental tax crowds out10 somevoluntary contributions, when subjects are given the chance to voteon such a tax, the tax does not significantly crowd out voluntary con-tributions. For example, subjects that voted between a high and a lowtax (4 out of 5 groups adopted the low tax) still voluntarily gave acomparable amount to the subjects without a tax. The coefficient inTable 3 shows that they gave only 0.275 more euros, although thisis not significant at the 10% level. Voting for a low tax did not signif-icantly modify average voluntary donations. However, when an

9 There is also an added confounding factor that 12 observations get dropped in theuniversity sample when including control variables, because of missing data in at leastone of the survey observations.10 We acknowledge the fact that Andreoni (1993) states that corner solutions, as op-posed to interior solutions cannot be used to test crowding out effects because theycreate a boundary issue. Our data may suffer from some problems because of that,however the corner solutions still allow us to measure incomplete crowing out. Fur-ther, estimates of treatment effects were largely robust to using a Tobit model that ex-plicitly accounts for the boundary problem (subjects could not give fewer than0 euros). These results are available from the authors upon request.

external tax was imposed, voluntary contributions did significantlydecrease by over 3 euros (significant at the 0.01 level).

In Fig. 1 we compare the contributions for the university subjectsthat participated in either the baseline condition or the vote high/low treatment. The left panel of Fig. 1 shows the average contributionsof the individuals depending onwhether they voted for a tax of 5 or 10and compares this to those who did not face a decision (did not vote)to impose a tax (i.e. the baseline condition for university subjects).This panel shows that those who voted for a tax of 10 voluntarily con-tributed an additional euro compared to those in the baseline, eventhough on average they had an additional mandatory contribution of8 euros. This shows evidence of a crowding-in of voluntary contribu-tions among those who vote for a high tax. Moreover, those whovoted for a mandatory contribution of 5 still had slightly higher volun-tary contributions than those in the baseline condition. This impliesthat those who voted for a low tax did not have their voluntary contri-butions crowded-out. Thus, given that there is significant crowding-infor some subjects, and no crowding-out for the remaining subjects, itappears that this condition may be favorable for fundraising, especial-ly among those who would vote for high mandatory taxes. However,the positive crowding-in effect is somewhat tenuous because it isbased on the behavior of only 5 people who voted for the high tax.

The right panel of Fig. 1 shows average individual contributions basedon the group-aggregated vote outcome. Here we see that individuals inthe group that passed a 10 euro mandatory contribution to the FSB gavevery little additional voluntary contributions to the 10 euro tax. However,those in groups that voted for the 5 euro mandatory contribution volun-tarily gave one more euro than those in the baseline condition. Thus,those in a group which pass a 10 euro tax appear to have their voluntarydonations crowded-out, while those in groups which pass the 5 euromandatory contribution have some crowding-in from the vote.

Taken together, the panels in Fig. 1 imply that those who vote for a10 euro mandatory contribution, yet are left with a 5 euro mandatorycontribution are more likely to give additional voluntary contributions.Thus, even thoughwe donotfind evidence that a group vote affects vol-untary contributions on average, it is possible that an individual's ownvote indicates a greater willingness to make voluntary contributions.

58 E. Blanco et al. / Ecological Economics 75 (2012) 52–60

That is, individuals who vote for a 10 euro tax and are stuck in a groupwith a 5 euro tax may conform to their earlier vote by contributingmore. This increased contribution appears to be driven simply by givingthem the opportunity to vote. A more formal analysis of this phenome-non is presented in Table 4 below.

The models reported in Table 4 report OLS estimates of voluntarycontributions using only data from university subjects in the baselineand vote high/low tax treatment. The first model of Table 4 modelsvoluntary contributions as a function of whether the individualvoted for a 10 euro mandatory contribution (voted for 10) andwhether the group passed the 5 euro mandatory contribution rule.Model 1 indicates that these are not powerful predictors of theamount of voluntary contributions. Model 2 of Table 4 adds an addi-tional variable as the interaction between personal voting andgroup outcome. This interaction is statistically significant at the 0.05level. The coefficient on the interaction represents the additionalnumber of euros a subject gives when they personally vote for a10 euro mandatory contribution and the group passes only a 5 eurocontribution. Subjects who voted for a 10 euro mandatory contribu-tion give more than 6 additional euros than those in the baseline con-dition that did not have any opportunity to vote. Thus, in this case,voting can increase the voluntary contributions of some memberseven if the group as a whole does not approve a mandatory tax.

This result implies that voting only has an effect for the minorityin a group. This seems different to expected behavior in a convention-al public good game where a rational actor might instead perceivethat not passing the vote is a signal for low overall contribution andthus also lower own contribution. Yet, in a conventional public goodgame, only participants in a single group provide the public good.Then, the marginal per capita return for each player is imposed by de-sign. Yet, the public good in our experiment (environmental protec-tion) is not a laboratory-created public good, but a real public good,with possibly a very low marginal per capita return not only for par-ticipants in the experiment but potentially any inhabitant or visitantto the islands, who can simultaneously be contributors. This result isdriven by few observations, and might deserve further investigationin the future for similar real public goods contexts.

5. Conclusion

This paper addresses the voluntary donations to environmental pro-jects by tourists and how these donations are influenced by the capacityof tourists to decide whether to impose a tax or the magnitude of it. Ourfirst conclusion from this analysis is that tourists rarely vote to self-impose a tax (when voting between a low tax and no tax) or to have ahigh tax (when voting between a low tax and a high tax) with majorityrule. The results from the voting indicate that most groups fail to have a

Table 4Voluntary contributions and voting in the vote high/low treatment.

(1)OLS

(2)OLS

Voted for 10 0.752 −1.722(1.43) (1.74)

Vote 5 passed 1.531 0.688(1.00) (1.02)

Voted for 10×Vote 5 passed 6.145**(2.75)

Constant 2.035*** 2.389***(0.68) (0.66)

R-squared 0.073 0.198Adj. R-squared 0.017 0.123F 1.297 2.635*N 36 36

Notes: Data only from student subjects in the baseline and vote high/low treatment.Coefficients with standard errors in parentheses. Two-tailed hypothesis tests:*pb0.10, **pb0.05, ***pb0.01.

majority of members that support such a tax. Only in one of the high/low tax vote groups did the high tax pass, imposing a 10 euro compulsorycontribution to all participants in the group. Thus, in general the votingtreatments fail to impose taxes or higher taxes on group members.

Further, we explore voluntary donations in voting treatments ascompared with non-voting treatments and find that the group-aggregated vote outcome does not significantly affect voluntary con-tributions to an environmental foundation. However, in some in-stances, individual voting decisions may increase the amount ofvoluntary donations for the individual. In all cases, however, votinginstitutions do not decrease the amount voluntarily donated to theenvironmental foundation, despite the fact that such institutions arerarely implemented. Thus, voting mechanisms do not appear to ap-preciably affect average contributions but they may increase donationlevels for some types of subjects.

Our results also imply that researchers studying tourism demandmay need to think carefully about the sample they study and the rep-resentativeness of that sample to the broader tourist population. It iscommon practice, at least in Spain, to sample tourists from the airportwhen studying tourism demand. Our analysis, however, found thatairport subjects were much more willing to donate money to theFSB than a different sample of tourists temporarily studying on the is-land. Further, the university sample behaves similarly (i.e. mean do-nations are a small percent of the total endowment) to populationsfound in field conditions throughout the world under similar experi-mental protocols. This suggests that airport subjects may behavequite anomalously when under study. Whether the airport sampleor the university sample is more representative of Majorcan touristsmore generally remains an open question; however, because the be-havioral differences are so substantial across samples, care shouldbe taken when generalizing results from one sample.

Finally, some broader lessons in terms of tourism-based tax policymight be cautiously applied. Voluntary donations alone do not appearto be as effective as combinations of voluntary donations andmandato-ry taxes, in terms of the ability to generate revenue for environmentalcauses. While mandatory and externally imposed taxes do appear tocrowd-out voluntary donations they do not completely crowd-outsuch donations (Lopez et al., 2011). Furthermore, this analysis suggeststhat whenmandatory taxes or the size of the taxes can be decided (thatis, tourists are allowed to vote for a tax rate) some types of tourists mayhave increased voluntary contributions, even if the vote for mandatorytaxes does not pass and thus the policy is not implemented.

Acknowledgements

We are particularly grateful to James Walker for all the time hespent advising us and his critical comments on the experimental de-sign. We also acknowledge the support received during the data col-lection by Pere Juanico, and several faculty members of the Universityof the Balearic Islands. We received valuable suggestions at the 4thNordic Conference on Behavioral and Experimental Economics, heldin Oslo, Norway, in 2009, and from the Experimental EconomicsReading Group from Bogotá, Colombia. Financial support from theGovernment of the Balearic Islands is gratefully acknowledged. Weassume complete responsibility for the final contents of this paper.

Appendix A

Introduction

This activity is part of a research project funded by the regionalGovernment of the Balearic Islands and conducted by a partnershipbetween Florida State University, in the United States, UniversidadJaveriana, in Colombia, and the University of the Balearic Islands.

This activity is composed of two main sections: (i) an experimentabout environmental decision making, and (ii) a short survey.

Table B.1Description of variables.

Variable Description Type of variable

Total contribution The sum of voluntary contribution plus tax Continuous(0–15)

59E. Blanco et al. / Ecological Economics 75 (2012) 52–60

Once you read this paper sheet it will take you 5 minutes toparticipate.

PAYMENT: During this activity you will have an opportunity toearnmoney. The amount of money you earn depends on the decisionsthat you and other participants in the experiment make. At the end ofthe activity you will be paid privately in cash for your decisions in theexperiment.

Voluntarycontribution

The voluntary contribution made by subject Continuous(0–15)

Trip experience a An additive index of variables used to assessthe subject's satisfaction with their trip.

Ordinal (0–45)

Environmentalism b An additive index of variables used to assessthe subject's environmental preferences.

Ordinal (0–4)

Number of visits The number of visits the subject has madeto Majorca.

Ordinal (1–100)

Age c Age of subject measured on a four-categoryscale.

Ordinal (1–4)

Education d Education of subject measured on asix-category scale.

Ordinal (1–6)

Eurozone country Home country of subject officially uses theEuros as currency

Binary (0,1)

a This index is taken from a series of nine questions we asked the subjects about theirvacation experience. Subjects were asked to rank, on a scale of 1 to 5, their satisfactionwith the scenery, beach, environmental quality, cleanliness of public areas, prices,treatment as a customer, hospitality from local people, safety and security, and tourist in-formation. A factor analysis confirmed that these measures co-vary closely together on asingle underlying factor; for ease of interpretation a single additive index was formed.

b This index is taken from the following four questions we asked the subjects abouttheir environmental preferences: 1) Whether or not one of the top four reasons theycame to the island was to enjoy the landscape and nature; 2) whether they make dona-tions to causes dealing with environmental protection; 3) whether they have a close con-tact to nature (hiking, biking, etc.) in their home country; and 4) whether they visitprotected natural areas in their home country. A factor analysis confirmed that thesemea-sures co-vary closely together on a single underlying factor; for ease of interpretation asingle additive index was formed.

c The categories are: 1) 30 years or below; 2) between 31 and 45; 3) between 46 and60; and 4) 61 or older.

d The categories are: 1) No formal education; 2) pre-school or kindergarten; 3) primary

This Experiment

In this experiment you will be randomly assigned to groups of 5.However, you will never know the identity of the other members ofyour group. The decisions of one group do not affect the decisionsor earnings of other groups.

Each of the subjects in your group of 5 has been given 15€. Yourdecision task is to decide how much of your 15€ you would like tovoluntarily allocate to a local environmental organization, the Foun-dation for a Sustainable Balearics (FSB). You will mark your decisionon a decision form paper, including a participant number, which isyour identification during the activity.

The FSB is a public-private non-profit organization, which was cre-ated on the 8th of July, 2004, whose aim is to propel a strategy of sus-tainable development. Their basic objectives are (1) heighteningawareness of the residents and tourists to the environmental and her-itage values of the Islands and the importance of their preservation;(2) inform residents and visitors alike, of the balance betweenhuman activity and the environment; and (3) fund raising in orderto support different types of performances to be held in natural set-tings and initiatives which strive for sustainability.

Your earnings consist of the money you decide to keep up to 15€.At the end of the activity, we will give you your earnings in cash. Themoney you decide to contribute to the FSB will be placed in a sealedenvelope with your participant number written down. At the end ofthe day, we will handle all the envelopes to the FSB. If you wouldlike to track your contribution, you may do so by reaching ToniMaura, Projects Director FSB, at tonimaura@balears-sostenible.comor 971612425, and verify your contribution was made under yourparticipant number. At the end of the study, the FSB will issue a cer-tificate will all the contributions received.

Example:

Suppose that each member of your group voluntarily allocated4€ to the FSB so that the total allocation from all members is4€×5=20€. Each group member's total earnings (the moneythat is kept) would then be 15€−4€=11€. At the end of thesession we would give you 11€ in cash. We would then depositthe 4€ you allocated to FSB in a sealed envelope with your par-ticipant number and at the end of the day we will handle all theenvelopes to the FSB.

To summarize, you will earn: 15€ minus the amount you decideto allocate to the FSB.

If you decide to participate, please raise your hand or call the at-tention of one of the researchers. In order to start the activity weneed to have at least 10 participants. As soon as we reach that num-ber, we will come by to give you the decision form and the survey.Once you decide to participate, please don't talk to anyone exceptone of the researchers.

CONFIDENTIALITY: All the information you will give us, is strictlyconfidential. You will never be asked to reveal your identity and yourname will never be associated with any of your decisions. In order tokeep your decisions private, please do not reveal your choices to anyother participant.

Appendix B

school; 4) secondary school; 5) bachelor degree; and 6) master's or PhD.

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