Public cooperation statements

Koessler, Ann-Kathrin; Page, Lionel; Dulleck, Uwe Article — Published Version Public cooperation statements Journal of Economic Interaction and Coordination Provided in Cooperation with: Springer Nature Suggested Citation: Koessler, Ann-Kathrin; Page, Lionel; Dulleck, Uwe (2021) : Public cooperation statements, Journal of Economic Interaction and Coordination, ISSN 1860-7128, Springer, Berlin, Heidelberg, Vol. 16, Iss. 4, pp. 747-767, https://doi.org/10.1007/s11403-021-00327-4 This Version is available at: https://hdl.handle.net/10419/287319 Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. 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If the documents have been made available under an Open Content Licence (especially Creative Commons Licences), you may exercise further usage rights as specified in the indicated licence. https://creativecommons.org/licenses/by/4.0/ Journal of Economic Interaction and Coordination (2021) 16:747–767 https://doi.org/10.1007/s11403-021-00327-4 REGULAR ARTICLE Public cooperation statements Ann-Kathrin Koessler1·Lionel Page2·Uwe Dulleck3 Received: 4 December 2019 / Accepted: 23 March 2021 / Published online: 15 April 2021 © The Author(s) 2021 Abstract Communication is a well-known tool to promote cooperation and pro-social behavior. In this study, we examine whether minimal communication in form of public consent with a pre-defined cooperation statement is sufficient to strengthen cooperation in groups. Within the controlled environment of a laboratory experiment, we identify ways by which non-enforceable cooperation statements are associated with higher levels of cooperation in a public good setting. At first, the statement triggers selection; socially oriented individuals are more likely to make the cooperation statement. In addition, we can show that a behavioral change takes place once the statement is made. This change can be attributed to commitment arising from the pledge and to increased coordination between the interaction partners. Depending on the institutional context, these drivers can vary in strength. Comparing compulsory and voluntary cooperation statements, we find that both are effective in motivating higher contributions to the public good. Keywords Cooperation ·Communication ·Pledge ·Social dilemma ·Pro-social behavior ·Policy making JEL Classification A13 ·C72 ·C91 ·H41 1 Introduction Many situations in daily life are characterized by a social dilemma structure; the collective is better off if everyone cooperates, but each individual has an incentive to defect and to act upon their self-interest. Hence, a central question in the social sciences is how to stimulate cooperation in group settings. Beside punishment and monitoring, BAnn-Kathrin Koessler [email protected] 1University of Osnabrueck, Barbarastr. 12, 49076 Osnabrueck, Germany 2University of Technology Sydney, Sydney, Australia 3Queensland University of Technology, Brisbane, Australia 123 748 A. -K. Koessler et al. communication has been shown to be an effective approach to strengthen pro-social behavior and cooperation in experimental studies (Ledyard 1995; Chaudhuri 2011). Traditionally, studies which examine experimentally the impact of communication allow their participants to engage in an open discussion before play. While the messages in this communication format are typically costless and non-binding, previous findings suggest that players consider them as a serious opportunity to coordinate (Ostrom et al. 1992). Communication helps to establish a common cooperation norm and improves the understanding of the game (Kerr and Kaufman-Gilliland 1994). In consequence, pre-play communication can stimulate higher cooperation levels in the respective public good games. In reality, howsoever, open discussions between all relevant actors may be time-consuming or simply not feasible (Messick et al. 1983). To restrict communication in these settings may help to ease coordination. In this study, we examine whether actors’ public consent to a cooperation statement is sufficient to promote cooperation within groups. The cooperation statement is predetermined and non-binding, i.e., it is cheap talk, and this is known by all involved actors. Given that a procedure like this is easier to implement than a common communication forum, and at a lower cost, we believe that it is important to understand if and how these cooperation statements may affect behavior. For example, it is contextdependent whether a voluntary or compulsory statement is more suitable, but our results suggest pro-social behavior lasts longer when all players make the statement. Previous research on communication in bilateral settings provides us with first indications as to why cooperation statements may be effective. Studies which give players the possibility to communicate before play, show that this exchange increases trust and trustworthiness. Individuals exhibit an aversion to lie (Gneezy 2005; Hurkens and Kartik 2009; Lundquist et al. 2009) and when they make a promise about future cooperation, they are likely to act consistently (Festinger 1957) and execute the promised behavior (Ellingsen and Johannesson 2004; Vanberg 2008; Charness and Dufwenberg 2006). Previous studies, however, also indicate that the engagement with the commitment may vary with the form of exchange. Conrads and Reggiani (2017), for example, show that cooperation promises are more likely in real-time communication than when communication is delayed. Social psychological studies, on the other hand, point to the importance of decision autonomy in commitments. Only when individuals feel that they have freely expressed the intention to help or to cooperate, they will feel committed to the promised behavior (Kiesler 1971; Linder et al. 1967; Schlesinger 2011). Elicited or pre-formulated promises, by contrast, have none or only a small effect on the consequent behavior (Charness and Dufwenberg 2010; Belot et al. 2010). At last, public promises have a stronger commitment effect than private pledges (Joule and Beauvois 1998); and being actively engaged in a pledge, i.e., statement-making is in some form effortful, increases the binding function (Kiesler 1971; Linder et al. 1967). Regarding honesty, the effect of pre-play pledges seems to be particularly pronounced. Studies analyzing the impact of solemn oaths or honor codes on behavior show that when vows are taken, participants are more likely to reveal their true preferences (Jacquemet et al. 2013; Carlsson et al. 2013), are less likely to lie in the experiment (Mazar et al. 2008; Jacquemet et al. 2019; Beck et al. 2020) and coordinate better due to more truthful communication (Jacquemet et al. 2018). While a first study suggests that pledging a solemn oath may also have a positive spillover 123 Public cooperation statements 749 on cooperation (Hergueux et al. 2016), we, on contrast, study the effect on behavior directly: we examine whether public consent with a cooperation statement stimulates pro-social behavior in social dilemmas. At last, this links our study to the literature on leader communication in social dilemmas. In these studies, one player has the opportunity to send a free message about intended contribution levels to the group. Whether these unilateral messages influence behavior depends on their credibility; Koukoumelis et al. (2012) find that contributions to the public good increase after the message, while in Dannenberg (2015) the leader message has rarely an effect. In the latter case, followers correctly anticipate that the leader will not realize her announced contribution level and hence do not get affected by the message.1In our experiment, we analyze a similar form of minimal communication, but the cooperation statement in our study differs in two fundamental aspects. First, the message is not endogenously chosen by one of the group members, but pre-determined by an external institution, that is by us, the experimenter. This allows us to determine what signal is offered as a coordination device. Second, we elicit a consent decision about the cooperation statement from each single player, so that everyone in the group has to take a stand. With this design, we identify ways by which non-enforceable cooperation statements are empirically associated with higher levels of cooperation in a public good setting. At first, we identify whether selection takes place that is more socially oriented people make the statement. First, we determine whether selection occurs, i.e., whether people are more socially oriented in making the statement. Subsequently, using our within-subject design, we evaluate whether in addition to a potential selection effect behavioral change occurs. Subjects which make the statement contribute more after the pledge, and contribution levels are highest when all group members make the statement. We attribute this to improved coordination among the group members and analyze with a separate treatment condition whether the behavioral effects change when the cooperation statements are compulsory rather than voluntary. In our experiment, both types of statements increase cooperation and produce, on average, similar contribution levels. The remainder of the paper is organized as follows. In Sect. 2, we describe the experimental design and list the behavioral predictions. In Sect. 3, we present the experimental results. We conclude with some discussion and potential insights for practice in Sect. 4. 2 Experiment 2.1 Design For this experiment, we employed a linear public good game with four players and a voluntary contribution mechanism. The experiment consisted of two stages, and in each stage, subjects played ten rounds of the public good game in partner matching. 1The communication in Dannenberg’s study was based only on the numerical announcement of the intended contribution level and the message was not in text format. Compared to Koukoumelis finding, this may have curtailed the message’s credibility. 123 750 A. -K. Koessler et al. Table 1 Experimental design Stage 1 Stage 2 N Control Standard PGG Standard PGG 64 Voluntary Standard PGG Voluntary statement standard PGG 64 Compulsory Standard PGG Compulsory statement standard PGG 64 The first stage served as a baseline to measure heterogeneity and allows us to carry out a within-subject analysis. At the beginning of each round, each subject was endowed with 20 Experimental Currency Units, which they could consume either privately or contribute to a public good. The payoff function was the following: p=20 −zi+0.4∗n j=1zj(1) zidenotes i’s contribution level, where 0 ≤zi≤20 and 0.4∗n j=1zjpresents the income from the project. Contributions to the public good increased the collective output, but the marginal per capita return of a contribution was less than one. A profit-maximizing individual may thus keep the entire endowment and free-ride on the contributions of the other players. Free-riding, however, diminishes the total welfare for all group members. After the first ten rounds, experimental groups were re-matched2and the treatment variations were implemented. Participants were randomly allocated between three groups: Control, Voluntary and Compulsory. Table 1 summarizes the design. In both treatment groups, a statement was offered to communicate the intended contribution behavior for the following rounds. The promise was directed to the other group members and stated that the player will make significant contributions to the project, that is at least 75% of the endowment in each of the following ten rounds. We have chosen a minimum of 75%, since it is higher than the generally observed average contributions in a public good game (40–60%), but lower than the Pareto optimal contribution level of 100%. Hence, some latitude in the contribution choices was possible. In the first treatment group (Voluntary), participants simultaneously decided whether or not to make the statement. The players knew that these pledge decision would be publicized before the first contribution decision. In the second treatment group (Compulsory), players had to make the statement in order to proceed in the experiment. In both cases, it was made explicit that making the statement had no consequence on the set of possible future choices and did not limit the decisions later in the experiment. All participants who decided to pledge had to type in the following, “I promise to contribute each round at least 15 ECUs to the project.” According to research in social psychology (Linder et al. 1967;Kiesler1971), commitment is stronger when individuals engage in the act of promise making. For this reason, we 2The rematching of players was done in a way that none of the players interacted twice. With 16 participants per session, a perfect stranger matching was guaranteed and this was common knowledge. 123 Public cooperation statements 751 decided that subjects had to key in the statement.3Before the first contribution decision in Stage 2, all players in the treatment groups learned which players in their group (also) made the statement. In the second stage, Statement-Makers were consequently labeled.4 To control how beliefs influenced the contribution choice, we asked subjects after their contribution decision to indicate their expectations about the contributions of the other players (first-order beliefs) and the guess of others’ expectations with respect to their own contributions (second-order beliefs). This belief elicitation was incentivized, following the quadratic scoring rule. After all subjects stated their beliefs, feedback was given about each group member’s individual contribution.5 At the end of each stage, three rounds were randomly selected to determine the payments; one round for the contribution decision and two rounds for the accuracy of the beliefs. By this mechanism, we minimized wealth effects and prevented hedging within a stage. 2.2 Behavioral predictions and identification strategies Under the assumption of purely self-serving and money maximizing behavior, contributions are expected to be 0 in all groups and stages. Statements, if they are made, are considered as meaningless by the group members and do not affect their contribution decisions. This also applies to the repeated setting of the game. A rational decision-maker will always break the promise in the last round and try to free-ride on the contributions of the others. Applying backward induction, the statement is consequently non-credible in all rounds of the game. Empirical evidence, however, shows human behavior deviates fundamentally from these predictions. Contributions in public good games are on average between 40−60% of the endowment in the first round of an experiment and deteriorate over the repetitions of the game (Ledyard 1995; Fehr and Gächter 2000; Chaudhuri 2011). Moreover, non-institutionalized, multilateral communication enhances the contribution levels significantly (Sally 1995; Bochet et al. 2006; Balliet 2009). Koukoumelis et al. (2012)’s study provides first evidence that also one-dimensional communication may be sufficient to motivate higher contribution levels. Following these insights, public and institutionalized cooperation statements may be associated with higher contributions to the public good in our experiment. This reasoning finds also support in the bilateral promise literature. Individuals are reluctant to lie; either because the person has a preference for keeping their word (Ellingsen and Johannesson 2004; Vanberg 2008; Di Bartolomeo et al. 2019) or because the promisor does not want to go against the social norm of keeping a promise (Binmore 2006; 3Subjects who decided not to pledge had to key in a neutral text: “I am a voluntary participant in this experiment, no coercion or interference has taken place.” This text was already introduced in the baseline stage and was of similar length as the contribution statement. 4Respective screenshots and instructions can be found in the Appendix. 5Croson and Marks (2001) find that feedback about single players’ contribution compared to information about the total contribution does not change the average contributions. Also, Fehr and Gächter (2000)do not find a difference in contributions when feedback is provided at an aggregate level or by showing the entire contribution vector. 123 752 A. -K. Koessler et al. Bicchieri and Lev-On 2007). Other authors argue that the effect is more indirect: the statement raises the expectations of others, the promisor anticipates this and is motivated by guilt aversion, that is the desire to avoid (the psychological costs from) disappointing the expectations of the interaction partners (Charness and Dufwenberg 2006; Ederer and Stremitzer 2017; Battigalli et al. 2013). Both theories, howsoever, suggest that making a statement increases contributions to the public good in our experiment. In the case of the voluntary statements, higher contribution levels observed in Statement-Makers may have two origins: First, the statement is more appealing to people who generally contribute more. If they make the statement, while others do not, the decision to pledge can be interpreted as a (true) signal about one’s contributor type.6 Hypothesis 1 (selection): Participants who contributed more in Stage 1 are more likely to make the statement. The second origin for higher contributions of Statement-Makers is that a behavioral change took place and that subjects indeed increased their contributions after the pledge. In this case, commitment and coordination come into play. If making a statement triggers commitment, either due to a preference for promise-keeping or due to guilt aversion, and the interaction partners are aware of this, they may consequently also adapt their contribution behavior. To be more specific, if subjects observe other group members are making the statement, they expect higher group contributions in the future. Following conditional cooperation (Fischbacher et al. 2001), this change in beliefs motivates the subject to also contribute more to the public good. We see improved coordination, besides commitment to the promised behavior, as a source for an increase in pro-social behavior after a pledge. Hypothesis 2 (behavioral change): Participants who make the statement subsequently increase their contributions to the public good in Stage 2 compared to their contributions in Stage 1. Given our experimental design, the Voluntary treatment condition allows us to disentangle the selection aspect from the behavioral effect of the statement by comparing the behavior before and after the pledge (Stage 1 vs. Stage 2 contributions). We can evaluate whether participants who voluntarily choose to make the statement, have on average, higher contributions in Stage 1 (selection). And we can determine if participants who voluntarily made the statement, increase their contributions in Stage 2 compared to Stage 1 (behavioral change). In regard to the comparison between the two statement forms, voluntary and compulsory, previous research suggests that forced statements trigger a weaker commitment than a voluntary statement (Kiesler 1971; Schlesinger 2011). And while lying or expectation-based guilt aversion (Charness and Dufwenberg 2006; Ederer 6As one reviewer pointed out, it is possible that sophisticated low contributors may disguise themselves and use the pledge to motivate their new group members to high contributions. In our experiment, however, this strategic motive seems to play a subordinate role; as we will see later in the results section, previous high contributions are a valid predictor for statement-making. 123 Public cooperation statements 753 and Stremitzer 2017; Battigalli et al. 2013) may still be in place, it can be expected that their effect is weaker than in the Voluntary setting, since also the interaction partners know that the statement was forced. To our knowledge, we are first to examine the eventual differences in behavior in the context of multilateral decision-making. Findings from studies analyzing the effect of bilateral promise-making support the hypothesis that the effect of compulsory promises is weak(er) (Linder et al. 1967; Charness and Dufwenberg 2010; Belot et al. 2010). Hypothesis 3 (voluntary vs. compulsory): Participants who made a compulsory statement change their contribution behavior to a lesser extent than participants who made the promise voluntarily. For the second driver of a behavioral change, namely improved coordination, we expect that it will matter how uniformly the cooperation statement gets adapted. Since we have no influence on the statement decision in the Voluntary treatment group, we will control for the resulting variations in the analysis. Of particular interest will be the behavioral change in groups in which all four players voluntarily decide to make the statement. We expect to observe particularly high contribution in these groups, since a strong coordination component will be paired with a self-driven commitment. 2.3 Experimental procedure The experiment was conducted at the experimental laboratory of the Queensland University of Technology, we used the experimental software CORAL (Schaffner 2013) and the online recruitment system ORSEE (Greiner 2015). The experiment lasted for about an-hour-and-a-half. Sessions were equally distributed over the three treatment groups. Before participants could start the experiment, comprehension questions needed to be answered correctly. The average payment was 25.3 AUD (app. 18 USD). The data compromise observations of 192 individuals and 3840 decisions in total. 3 Results Starting with the average treatment effect, we examine the contribution levels in Stage 2 as opposed to Stage 1 in the control and the two treatment conditions (Table 2). Figure 1 depicts the corresponding differences in individual mean contributions. The graphical inspection suggests that when the game was played for the second time, average group contributions in the Control group were smaller. In the treatment groups, on contrast, average group contributions were higher than before. In the following, we will use regression analyses to analyze these differences and to examine ways by which the non-enforceable cooperation statements can be associated with such higher contribution levels. At first, we will analyze the behavior in the Voluntary treatment group; we will identify whether there was selection in making the statement and whether behavior in addition changed after the pledge. In a second step, we will then compare how the effect of the statement varied when the pledge 123 754 A. -K. Koessler et al. Table 2 Individual mean contributions Stage 1 and Stage 2 Contributions Stage 1 Stage 2 Number participants Control 8.70 (4.67) 7.65 (4.52) 64 Voluntary 8.57 (3.35) 10.08 (5.77) 64 Non-Takers 7.56 (2.83) 7.52 (4.98) 33 Statement-Makers 9.65 (3.56) 12.82 (5.33) 31 Compulsory 10.61∗(6.02) 13.13 (5.61) 64 Number of participants 192 Standard deviations are in parentheses. ∗Stage 1 contributions in the Compulsory group were on average higher than in the Voluntary and Control group. This was due to a strong variation across the experimental groups. In the regression analyses, we control for these initial differences and can show that they do not impair the findings presented in the following Fig. 1 Difference in mean contributions in Stage 2 compared to Stage 1 was voluntary or compulsory, and how the respective effects evolved over the course of interactions. 3.1 Voluntary statement Table 3presents the results of OLS regression models estimating the average individual contributions in Stage 1 and Stage 2 for the Control and Voluntary treatment group. The Control group’s contributions in Stage 1 serve as baseline. Model 1 analyzes at an aggregate level the change in contribution behavior after the pledging possibility. We find the same dynamic as in Fig. 1; contributions in the Voluntary treatment group increased in Stage 2 (after the pledge), as opposed to the Control group, where contributions decreased. In consequence, contributions in Stage 2 of the Voluntary treatment group are significantly higher (F=3.85, p=0.05) 123 Public cooperation statements 761 tion level. This finding points again to the benefits of improved coordination when everyone makes the statement. 4 Conclusion Our results suggest that public cooperation statements can help promote pro-social behavior in public good settings, even if the pledge is only in the form of a public consent with a given statement. In practice, we find such consent schemes with cooperation statements, for example, in professional codes of conducts. Based on our within-subject design, we were able to show that individuals get, in contrast to rational choice predictions, affected by the pledge and that the behavioral effects are not only due to selection. Making a cooperation statement leads to an increase in pro-social behavior. Furthermore, we argued that this behavioral change has two drivers, first, the self-driven commitment to fulfill the pledge, and second, the benefit of improved coordination between the interaction partners. In contrast to findings from bilateral interactions, we show that in social dilemma situations compulsory cooperation statements are not less effective in promoting cooperation than voluntary statements. On the contrary, they may even work better when the general willingness to make a voluntary pledge is low. To what extent are these results specific to the artificial situation in an experimental laboratory and what conclusions can be drawn for the real world? In our experiment, it was clearly defined what was considered a contribution to the public good and which behavior resembled compliance with the pledge. In real-world settings, this is rarely the case. Sometimes deviations can be easily identified, but in most cases, the distinction between violating against the promised cooperation and simply acting in a less socially acceptable way is blurred. Hence, the abstraction in our experiment naturally impairs the external validity of our findings. However, the purity of incentives and the clarity of the decision setting allowed us to identify two drivers that motivate behavioral change when public cooperation statements are used—intrinsic commitment to the promised behavior and improved coordination between the interaction partners. For future research, it would be interesting to probe the workings of these two drivers in the field. In general, our research suggests that public cooperation statements, although not binding, can help to promote pro-social behavior in social dilemma situations. Compared to legally binding rules and open discussion forums, public consent with pre-defined statements may be a solution that is simpler and less costly to implement and yet promotes contributions to the public good. Supplementary Information The online version contains supplementary material available at https://doi. org/10.1007/s11403-021-00327-4. Acknowledgements The authors thank Uri Gneezy, Nicholas Jaquemet, Richard Jefferson, Sarah Necker, Pedro Rey-Biel, Benno Torgler, Caroline van Bers and Israel Waichman for their valuable comments on earlier versions of this paper. The authors would also like to express their special thanks to two anonymous reviewers whose constructive feedback has contributed to improving the quality of this manuscript. Ann- 123 762 A. -K. Koessler et al. Kathrin Koessler thanks the QUT Business School for the funding of the experiments and the Alexandervon-Humboldt Foundation for the support. 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Appendix Subject pool See Tables 6,7and Fig.3 Table 6 Summary statistics Variable Mean Std. Dev. Min. Max. N Econ (%) 0.56 0.50 0 1 192 Undergrad (%) 0.85 0.23 0 1 192 Female (%) 0.46 0.50 0 1 192 Age 22.60 6.35 17 63 192 Income 171.53 16.05 50 1000 144 Finsat (%) 0.32 0.468 0 1 175 lessRelig 4.43 1.55 1 6 175 CRT 1.21 1.12 0 3 192 SRM 5.83 1.51 4 11 191 SDS 4.43 2.35 0 11 190 123 Public cooperation statements 763 Table 7 Demographics across treatment groups Treatment groups Control Voluntary Compulsory Total Econ–Fin–Bus (%) 57.8 54.7 56.3 56.3 Undergrad (%) 92.2 84.4 78.1 84.9 Female (%) 45.3 45.3 48.4 46.4 Age 22.94 23.64 22.23 22.93 Income 174.44 169.79 170.59 170.53 Finsat 0.29 0.34 0.33 0.32 lessRelig 4.40 4.63 4.27 4.43 CRT 0.95 1.34 1.33 1.21 SRM 5.67 5.86 5.97 5.83 SDS 4.27 4.46 4.57 4.43 N64 63 63 190* *Two subjects did not answer the psychological questionnaires Contributions of groups with n=4 statement-makers Fig. 3 Contributions in Stage 1 and 2, Statements. Note: This figure displays average contributions for each round in Stage 1 and Stage 2. The development of the two groups in the Voluntary treatment, in which all group-members decided to make the statement voluntarily, is plotted separately Demographic characteristics of statement-makers In the following, we shed light on the characteristics of subjects who voluntarily made the statement in the Voluntary treatment group. For this purpose, we use demographic data and information from psychological measures we elicited in a post-experimental 123 764 A. -K. Koessler et al. questionnaire. We asked subjects for their sex, age, degree, course and religiosity.8 We also asked five questions from the Socio-moral Reflection Measure Questionnaire (Basinger and Gibbs 1987; Gibbs et al. 2013), which address socio-moral values like truth-telling. The selected questions asked for participant’s attitude toward promises and lying.9We also elicited a short version of the Crowne and Marlow Social Desirability Scale (SDS). This scale is often used in Psychology and Clinical Research to measure the need for social approval.10 A person with a high SDS score is more likely to perform certain behavior due to a desire to be socially accepted or approved. Ultimately, as an estimator for strategic reasoning, we integrated the cognitive reflection test (CRT) (Frederick 2005). This test is designed to assess an individual’s ability to suppress an intuitive response, which is incorrect, and engage in further reflections that lead to the correct response. Answers were incentive compatible so that participants were paid 1 AUD for each correct answer. The CRT measure ranges from 0 to 3, indicating a person with a high CRT score is able to resist intuitively compelling responses. Table 8shows the likelihood that a participant takes the statement voluntarily in Stage 2 based on the demographic characteristics. Model 1 takes into account a participant’s study major and degree, gender and age as well as the experience with economic experiments. The variables Female, Econ and Postgraduate are dummy variables which take the value one when the participant was, respectively, female, studied Economics or enrolled in a postgraduate course. Model 2 predicts the likelihood of making the voluntary statement based on the extent to which a participant was satisfied with his or her financial situation and the degree of religiosity. Model 3 uses the psychological measurements we elicited in the experiment as explanatory variables. Model 4 combines all previous three models and Model 5 controls additionally for the experience a participant has made in the previous stage (average contribution of the other group members in Stage 1) and the own contribution behavior in Stage 1. The results show that only own contribution behavior in Stage 1 and gender have a significant and robust impact on the decision to voluntarily make a cooperation statement. When a participant was female, she was 40% less likely to make the voluntary statement (p=0.016 in Model 5). 8To have an indication how religious participants were, we asked “Apart from weddings, funerals and christenings, how often do you attend religious services these days?” The variable was coded with “More than once a week” (1), “Once a week” (2), “Once a month” (3), “Once a year” (4), “Less often than once a year” (5), “Never” (6). The observed average of 4.43 suggests that participants on average went to church once per year or less; apart from weddings, funerals and christenings. 9We asked the following questions: (1) How important is it for people to keep promises, if they can, to friends? (2) How important is it for people to keep promises, if they can, even to someone they hardly know? (3) How important is it for parents to keep promises, if they can, to their children? (4) How important is it for people to tell the truth? The variable was coded in reverse order: very important (1), important (2), not important (3). Thus, a high score in SRM indicates that the person stated that he or she perceives promise-keeping as less important. 10 The original version includes 50 items, we used a shorter version from Fischer and Fick (2003) which is proofed to be also valid and internally consistent (Barger 2002). 123 Public cooperation statements 765 Table 8 Demographic characteristics of Statement-Makers Variables Model 1 Model 2 Model 3 Model 4 Model 5 Econ −0.0611 −0.170 −0.0588 (0.138) (0.171) (0.189) Postgrad 0.187 0.383 0.535* (0.209) (0.273) (0.310) Experiment 0.153 0.219 0.259 (0.146) (0.181) (0.209) Female −0.276** −0.418*** −0.395** (0.130) (0.156) (0.163) Age −0.00695 −0.00876 −0.00993 (0.0107) (0.0162) (0.0182) Finsat −0.0876 −0.153 −0.150 (0.143) (0.169) (0.185) lessRelig 0.0537 0.0573 0.0632 (0.0446) (0.0555) (0.0579) CRT −0.0241 −0.0571 −0.0497 (0.0560) (0.0732) (0.0756) SRM 0.0607 0.0393 0.0555 (0.0388) (0.0470) (0.0503) SDS 0.0540* 0.0407 0.00774 (0.0310) (0.0375) (0.0416) Contrib_S1 0.0662** (0.0305) OthersContrib_S1 −0.00856 (0.0140) Observations 64 56 63 55 55 This table presents the marginal effects (calculated at the means of all variables) from a probit regression on the likelihood that a participant takes voluntarily the statement. Standard errors are in parentheses. ***, **, * indicate significance at the 1%, 5% and 10% levels, respectively References Balliet D (2009) Communication and cooperation in social dilemmas: a meta-analytic review. J Confl Resolut 54(1):39–57 Barger SD (2002) The Marlowe–Crowne affair: short forms, psychometric structure, and social desirability. J Personal Assess 79(2):286–305 Basinger KS, Gibbs JC (1987) Validation if the social moral reflection objective measure—a short form. Psychol Rep 61(1):139–146 Battigalli P, Charness G, Dufwenberg M (2013) Deception: the role of guilt. J Econ Behav Organ 93:227–232 Beck T, Bühren C, Frank B, Khachatryan E (2020) Can honesty oaths, peer interaction, or monitoring mitigate lying? J Bus Ethics 163(3):467–484 Belot M, Bhaskar V, van de Ven J (2010) Promises and cooperation: evidence from a TV game show. J Econ Behav Organ 73(3):396–405 Bicchieri C, Lev-On A (2007) Computer-mediated communication and cooperation in social dilemmas: an experimental analysis. Politics Philos Econ 6(2):139–168 123 766 A. -K. Koessler et al. Binmore K (2006) Why do people cooperate? Politics Philos Econ 5(1):81–96 Bochet O, Page T, Putterman L (2006) Communication and punishment in voluntary contribution experiments. J Econ Behav Organ 60(1):11–26 Carlsson F, Kataria M, Krupnick A, Lampi E, Lfgren SA, Qin P, SternerSterner T (2013) The truth, the whole truth, and nothing but the truth a multiple country test of an oath script. J Econ Behav Organ 89:105–121 Charness G, Dufwenberg M (2006) Promises and partnership. Econometrica 74(6):1579–1601 Charness G, Dufwenberg M (2010) Bare promises: an experiment. Econ Lett 107(2):281–283 Chaudhuri A (2011) Sustaining cooperation in laboratory public goods experiments: a selective survey of the literature. Exp Econ 14(1):47–83 Conrads J, Reggiani T (2017) The effect of communication channels on promise-making and promisekeeping: experimental evidence. J Econ Interact Coord 12(3):595–611 Croson R, Marks M (2001) The effect of recommended contributions in the voluntary provision of public goods. Econ Inq 39(2):238 Dannenberg A (2015) Leading by example versus leading by words in voluntary contribution experiments. Soc Choice Welf 44(1):71–85 Di Bartolomeo G, Dufwenberg M, Papa S, Passarelli F (2019) Promises, expectations & causation. Games Econ Behav 113:137–146 Ederer F, Stremitzer A (2017) Promises and expectations. Games Econ Behav 106:161–178 Ellingsen T, Johannesson M (2004) Promises, threats and fairness. Econ J 114(495):397–420 Fehr E, Gächter S (2000) Cooperation and punishment in public goods experiments. Am Econ Rev 90(4):980–994 Festinger L (1957) A theory of cognitive dissonance. Stanford University Press, Stanford Fischbacher U, Gächter S, Fehr E (2001) Are people conditionally cooperative? Evidence from a public goods experiment. Econ Lett 71(3):397–404 Fischer D, Fick C (1993) Measuring social desirability: short forms of the Marlowe–Crowne social desirability scale. Educ Psychol Meas 53(2):417–424 Frederick S (2005) Cognitive reflection and decision making. J Econ Perspect 19(4):25–42 Gibbs JC, Basinger KS, Fuller D, Fuller RL et al (2013) Moral maturity: measuring the development of sociomoral reflection. Routledge, Milton Park Gneezy U (2005) Deception: the role of consequences. Am Econ Rev 95(1):384–394 Greiner B (2015) Subject pool recruitment procedures: organizing experiments with orsee. J Econ Sci Assoc 1(1):114–125 Hergueux J, Jacquemet N, Luchini S, Shogren J (2016) Leveraging the honor code: public goods contributions under oath. Technical report, HAL Hurkens S, Kartik N (2009) Would I lie to you? On social preferences and lying aversion. Exp Econ 12(2):180–192 Jacquemet N, Joule R-V, Luchini S, Shogren JF (2013) Preference elicitation under oath. J Environ Econ Manag 65(1):110–132 Jacquemet N, Luchini S, Rosaz J, Shogren JF (2019) Truth telling under oath. Manag Sci 65(1):426–438 Jacquemet N, Luchini S, Shogren JF, Zylbersztejn A (2018) Coordination with communication under oath. Exp Econ 21(3):627–649 Joule R, Beauvois J (1998) The free will compliance: How to get people to freely do what they have to do. PUF, Paris Kerr NL, Kaufman-Gilliland CM (1994) Communication, commitment, and cooperation in social dilemma. J Personal Soc Psychol 66(3):513 Kiesler CA (1971) The psychology of commitment: experiments linking behavior to belief. Academic Press, New York Koessler A-K (2019) Setting new behavioral standards: sustainability pledges and how conformity impacts their outreach. Available at SSRN 3369557 Koessler A-K, Torgler B, Feld LP, Frey BS (2019) Commitment to pay taxes: results from field and laboratory experiments. Eur Econ Rev 115:78–98 Koukoumelis A, Levati MV, Weisser J (2012) Leading by words: a voluntary contribution experiment with one-way communication. J Econ Behav Organ 81(2):379–390 Ledyard JO (1995) Public goods: a survey of experimental research. Princeton University Press, Princeton Linder DE, Cooper J, Jones EE (1967) Decision freedom as a determinant of the role of incentive magnitude in attitude change. J Personal Soc Psychol 6(3):245 123 Public cooperation statements 767 Lundquist T, Ellingsen T, Gribbe E, Johannesson M (2009) The aversion to lying. J Econ Behav Organ 70(1):81–92 Mazar N, Amir O, Ariely D (2008) The dishonesty of honest people: a theory of self-concept maintenance. J Market Res 45(6):633–644 Messick DM, Wilke H, Brewer MB, Kramer RM, Zemke PE, Lui L (1983) Individual adaptations and structural change as solutions to social dilemmas. J Personal Soc Psychol 44(2):294–309 Ostrom E, Walker J, Gardner R (1992) Covenants with and without a sword: self-governance is possible. Am Political Sci Rev 86(02):404–417 Sally D (1995) Conversation and cooperation in social dilemmas: a meta-analysis of experiments from 1958 to 1992. Ration Soc 7(1):58–92 Schaffner M (2013) Programming for experimental economics: introducing CORAL—a lightweight framework for experimental economic experiments. QuBE Working Papers 016, QUT Business School, Brisbane, Australia Schlesinger HJ (2011) Promises, oaths, and vows: on the psychology of promising. Taylor & Francis, Milton Park Vanberg C (2008) Why do people keep their promises? An experimental test of two explanations. 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