Endogenous Move Structure and Voluntary Provision of Public Goods: Theory and Experiment

In this paper, we examine voluntary contributions to a public good, embedding Varian's (1994) voluntary contribution game in extended games that allow players to choose the timing of their contributions. We show that predicted outcomes are sensitive to the structure of the extended game, and also to the extent to which players care about payoff inequalities. We then report a laboratory experiment based on these extended games. We find that behavior is similar in the two extended games: subjects avoid the detrimental move order of Varian's model, where a person with a high value of the public good commits to a low contribution, and instead players tend to delay contributions. These results suggest that commitment opportunities may be less damaging to public good provision than previously thought.     

An Application of the English Clock Market Mechanism to Public Goods Games

This paper reports an experimental study of the public goods game in which contributions are not submitted all at once but incrementally as coordinated in real time by a clock. Individuals press a button as soon as the clock equals their willingness to contribute. By providing information about the point at which subjects stop further contributions we find evidence for conditionally cooperative behaviour: A subject's decision to stop contributing induces an immediate reaction of the other group members.     

‘Expressive’ obligations in public good games: Crowding-in and crowding-out effects

We study individual contributions in a repeated linear public good experiment in which, in each period, subjects are required to contribute a minimum amount and face a certain probability of being audited. Audited subjects who contribute less than the required amount are convicted to pay the difference between the obligation and the voluntary contribution. We investigate the ‘expressive’ force of the obligations. While at early stages subjects contribute the minimum level, with repetition contributions decline below the required amount. We observe that expressive obligations exert a rather robust crowding-out effect on voluntary contributions as compared to a linear public good game. Crowding-out is stronger when payments collected through the auditing procedure are distributed to subjects rather than when they are a deadweight loss.     

Giving little by little: Dynamic voluntary contribution games

Charitable contributions are frequently made over time. Donors are free to contribute whenever they wish and as often as they want, and are frequently updated on the level of contributions by others. A dynamic structure enables donors to condition their contribution on that of others, and, as Schelling [Schelling, Thomas C., The Strategy of Conflict Cambridge, MA: Harvard University Press, 1960.] suggested, it may establish trust thereby increasing charitable giving. Marx and Matthews [Marx, Leslie, and Steven Matthews, “A Dynamic Voluntary Contribution to a Public Project,” Review of Economic Studies, 67, 2000, 327-358.] build on Schelling's insight and show that multiple contribution rounds may secure a provision level that cannot be achieved in the static, one-shot setting, but only if there is a discrete, positive payoff jump upon completion of the project. We examine these two hypotheses experimentally using static and dynamic public good games. We find that contributions are indeed higher in the dynamic than in the static game. However, in contrast to the predictions, the increase in contributions in the dynamic game does not depend critically on the existence of a completion benefit jump or on whether players can condition their decisions on the behavior of other members of their group.     

Dissertation abstract: Contribution to a public good - Theoretical analysis and experimental evidence

The work undertook is located between Public Economic Theory and Experimental Economics. The object of the thesis consists in analysing the aggregate behavior and the individual heterogeneity in a voluntary contribution game. The thesis defended here is that overcontribution in comparison to the Nash equilibrium of the game, can not be explained neither by judgement errors, nor by the information on the individual behaviour of the members in a one given group. The level of contribution observed remains nevertheless inferior to the one simulated using the E.W.A. learning model. The dissertation is composed of three parts and six chapters. The first chapter expresses the various theoretical mechanisms of production of a public good, while the second one presents an overview of the experimental literature using voluntary contribution mechanisms. The second part carries on the introduction of an interior solution in a public good game in order to distinguish an explanation of overcontribution in terms of mistakes or strategies. While chapter three presents the most important works in literature that use an interior solution, the fourth chapter constitutes a personal contribution consisting in an experiment with an interior optimum. Our main result is that individuals contribute a constant part of their social optimum and that overcontribution is not explained by error. We test then the simple learning model R.L. using the observed data on the aggregate level. This model predicts well the observed behaviour. The third part is composed of two experiments where the environment of players is modified. We introduce in chapter five promises as cheap talk and find that they increase contributions at the aggregate level. In chapter six, various conditions of information on individual contributions are tested. The parameter tested is the level of information on “neighbours” contributions given to players. One of the treatments presents full information about individual contributions of the members of the group, while this information is incomplete in the other treatments. Our results show that information has no effect on the level of contribution. We simulate then the EWA learning model both at the aggregate and the individual levels and compare the simulated data to the experimental one. These simulations predict a level of contribution that is higher that the one observed in the experiment. JEL Classification C91, C92, H41 Dissertation Committee: Alan Kirman (Ph.D. Advisor), Université d’Aix-Marseille III Marie-Claire Villeval (Chair), GATE, Lyon, France Jordi Brandts, Universitat Autonoma Barcelona, Spain Charles Noussair, Emory University, Alanta, GA, U.S.A. Sylvie Thoron, GREQAM & Université du Var, France Marc Willinger, Université de Montpellier I, France     

Heterogeneity,impatience, and dynamic private provision of a discrete public good

We analyze dynamic private provision of a discrete public good by heterogeneous agents, who differ in terms of their levels of impatience, in a differential game framework. In contrast to the strategic complementarity result for homogeneous individuals, we show that an asymmetric completion Markov perfect equilibrium exists, where the individual contributions and the strategic behaviors depend crucially on an impatience differential: the difference in rates of time preference across groups of individuals. When this differential is insignificant, contributions of both types of individuals are strategic complements. On the other hand, when this impatience differential exceeds a threshold, the contributions of impatient individuals become strategic substitutes, whereas the contributions of patient individuals remain strategic complements. We show that group size has an interesting role to play in the strategic behavior: increasing the number of patient individuals aggravates the incentives to free‐ride by the impatient agents. We also derive a condition under which all the socially beneficial projects get completed in the equilibrium.     

Beliefs and Public Good Provision with Anonymous Contributors

We analyze a static game of public good contributions where finitely many anonymous players have heterogeneous preferences about the public good and heterogeneous beliefs about the distribution of preferences. In the unique symmetric equilibrium, the only individuals who make positive contributions are those who most value the public good and who are also the most pessimistic; that is, according to their beliefs, the proportion of players who most like the public good is smaller than it would be according to any other possible belief. We predict whether the aggregate contribution is larger or smaller than it would be in an analogous game with complete information and heterogeneous preferences, by comparing the beliefs of contributors with the true distribution of preferences. A trade‐off between preferences and beliefs arises if there is no individual who simultaneously has the highest preference type and the most pessimistic belief. In this case, there is a symmetric equilibrium, and multiple symmetric equilibria occur only if there are more than two preference types.     

Do binding agreements solve the social dilemma?

We investigate experimentally whether “binding agreements” can provide a solution to the social dilemma that arises in the presence of pure public goods. Signing a binding agreement can prevent players from free riding on the contributions to the public good. However, a well known theoretical result is that the outcome of the endogenous formation of agreements is not necessarily efficient. Our setting is a bargaining game in which agreements form sequentially. The individual level of contribution to the public good increases with the size of the coalition reaching an agreement and the global agreement is always the socially optimal structure. There are two equilibrium outcomes, the global agreement and an asymmetric structure, which consists of two coalitions of different sizes, the small one free riding on the contributions of the larger one. We run an experiment which lends force to the theoretical result that outcomes may be inefficient. However, subjects do not play Nash and the experimental outcome is, on average, even more inefficient than the theory predicts. Our analysis leads to the conclusion that different types of behaviour co-exist.     

Strategic Complementarity in the Dynamic Private Provision of a Discrete Public Good

Individual voluntary contributions to a discrete public good are shown to be strategic complements in a dynamic private provision game. This is in contrast to a public good that can take on any value in a continuum where they are strategic substitutes.     

Giving at the close: Experimental evidence on cooperation in contributing to a public good

We present a simple dynamic model of contributions to a public good. We test the model by conducting a public good game experiment and fundraising experiment among religious Jewish students for the procurement of sustainable supplies for their campus synagogue. The results of the experiments show a high level of cooperation; particularly, the results of the public good experiment show that contributions are above the predicted optimum. Nevertheless, in accordance with the economic theory, we find that the contribution path is upward sloping and contributions increase with the benefit of the public good. Our findings also suggest that the level of contributions and their path are affected by peer and gender effects.     

Finitely Repeated Voluntary Provision of a Public Good

This paper theoretically explores the voluntary provision of a public good when either one of the following holds: (i) agents’ utility is the sum of their monetary earnings and a nonmaterial component, or (ii) agents’ exhibit satisficing behavior. We show that a small degree of either nonmaterial payoffs or satisficing behavior can generate large contributions in a finitely repeated game, even if the incentive to free‐ride on others’ contributions calls for negligible public good provision in the static game. The equilibrium is characterized by a sharp decline in contributions toward the end of the game. Several comparative results regarding group size and technology are consistent with laboratory data obtained in experimental studies. The model also predicts the restart effect observed in previous experiments.     

Improving Voluntary Public Good Provision Through a Non-governmental,Endogenous Matching Mechanism: Experimental Evidence

Social norms can help to foster cooperation and to overcome the free-rider problem in the private provision of public goods. This paper focuses on the endogenous establishment of an average-oriented norm which sanctions deviations from average public good contributions. In a laboratory experiment, we analyse whether subjects are willing to implement a punishment and reward scheme at their own expense by applying the theory of non-governmental norm enforcement put forward by Buchholz et al. (J Public Econ Theory 16(6):899–916, 2014). Based on their theory, which omits a central authority but introduces an endogenously determined enforcement mechanism, we implement a two-stage public good game. In the first stage, subjects determine the strength of the sanctioning mechanism on their own. In the second stage, they decide on their personal contributions to the public good based on the established mechanism. In line with comparable pool punishment experiments, we find that subjects are apparently willing to contribute funds in order to establish a norm enforcement mechanism. Groups over-invest in the mechanism, but this over-investment decreases over time. These investments seem to be driven by the subjects’ previous individual contributions and partly by a number of strategic considerations, i.e. the previous average contribution made to the public good lowers the investment in the sanctioning mechanism. In the second stage of our experiment, higher norm enforcement parameters tend to lead to higher public good contributions. The earnings with the mechanism are on average higher than without.     

Dissertation abstract: A status theory of collective action

The “collective action problem” describes situations where each person in a group can individually profit more by withholding contributions to group goals. However, if all act in their material self-interest no public good is produced and all are worse off. I present a new solution to the collective action problem based on status. I argue that contributions to collective action increase an individual’s status in the group because contributions create perceptions of high group motivation, defined as the relative value an individual places on group versus individual welfare. Individuals are predicted to receive a variety of social and material benefits for their contributions to the group. These rewards can help explain why individuals contribute to collective action. Four laboratory studies tested the theory. In Study 1, following interaction in a 6-person public goods game, participants reported viewing higher contributors as more group motivated and higher status. Higher contributors also wielded more interpersonal influence in task interactions with participants. Participants also cooperated with higher contributors more, and allocated greater altruism to them in a Dictator game. Study 2 addressed an exchange-theoretic alternative explanation for the findings of Study 1, showing that observers of collective action who did not benefit from higher contributors’ contributions to the public good, nonetheless rated them as higher status, cooperated with them more, and gave them greater altruistic gifts. These results show that collective action contributors can earn social and material benefits even outside the group. Study 3 more directly tested the mediating role of group motivation. Contributors who sacrificed a greater proportion of resources for the collective action were rated as more group motivated and higher status than a moderate proportional contributor, even though the amounts they contributed were the same. These findings support the theory, and underscore the significance of self-sacrifice in the acquisition of status in collective action. Study 4 investigated the effects of status rewards on contributors’ behavior towards and perceptions of the group. Participants who received positive status feedback for their contributions subsequently contributed more than those who did not. Rewarded participants also identified more with the group and saw it as having greater solidarity and cohesion. I conclude by discussing theoretical implications and future research. JEL Classification C71     

Providing public goods in the absence of strong institutions

This paper proposes a simple two-stage mechanism to establish positive contributions to public goods in the absence of powerful institutions to provide the public good and to sanction free-riders. In this mechanism players commit to the public good by paying a deposit prior to the contribution stage. If there is universal commitment, deposits are immediately refunded whenever a player contributes her specified share to the public good. If there is no universal commitment, all deposits are refunded and the standard game is played. For suitable deposits, prior commitment and full ex post contributions are supported as a subgame-perfect Nash equilibrium for the resulting game. As the mechanism obviates the need for any ex post prosecution of free-riders, it is particularly suited for situations where players do not submit to a common authority as in the case of international agreements.     

Intragroup competition in public good games: The role of relative performance incentives and risk attitudes

We analyze a public good game (PGG) with intragroup competition in which, generally but not always, the dominant strategy is to not contribute; therefore, free riding is the unique Nash equilibrium, not achieving Pareto efficiency. We propose a PGG setup where subjects' contributions are rewarded with different individual returns following a rank‐order voluntary contribution mechanism. It is found that the resulting competition for a better return significantly increases contributions. This effect is sensitive to the salience of return differences rewarding higher contributions. Furthermore, the positive effect of return differences on contribution levels depends on an individual's return‐to‐risk sensitivity as elicited through an independent risk elicitation task.     

Common fate,game harmony and contributions to public goods: experimental evidence

We experimentally study the effects of common fate on voluntary contributions to linear public goods. In each period, earnings are assigned to subjects according to the outcome of a lottery. In ‘common fate’, ‘independent fate’ and ‘rival fate’ treatments, the lottery outcomes of group members are (respectively) positively correlated, stochastically independent and negatively correlated. We observe the highest contributions and strongest reciprocity under common fate. Contrary to the game harmony hypothesis, contributions are not lower under rival fate than under independent fate. Surprisingly, under rival fate, having won the lottery in one period induces higher contributions in the next period.     

Moral Opinions are Conditional on the Behavior of Others

In social dilemmas individual behavior creates external effects on others. In such situations, a person's opinions concerning right and wrong might influence his behavior. Understanding moral opinions therefore is important. This paper reports on an experiment which shows that moral opinions are conditional on the behavior of others. This is demonstrated by the finding that a large majority of subjects in a public good game experiment report personal normative beliefs that increase with the actual contributions made by group members. This finding is important for the design of policies attempting to sustain public good provisions.     

Imitation and the Incentive to Contribute Early in a Sequential Public Good Game

Whether motivated by reciprocity or conformity, imitation is common in public good contexts. We consider the incentive for an agent to contribute to a public good if he expects imitation from others. Using a sequential public good game with exogenous ordering, we show that agents early enough in the sequence who believe imitation to be sufficiently likely would want to contribute. By contributing, they expect total contributions to increase significantly. We also show that preferences determine how early an agent need be, that the observed share of imitators in experiments is sufficiently high to warrant contribution and that an increase in group size reduces the incentive to contribute.     

Cooperation and framing effects in provision point mechanisms: Experimental evidence

Andreoni (1995) showed that pure framing effects may influence contribution in Voluntary Contribution Mechanisms (VCM) by comparing a standard public goods game, called the positive frame condition (giving to the public good), with a negative frame condition (taking from the public good) where the subjects' choice to purchase a private good makes the other subjects worse off. This paper aims at testing the robustness of such framing effects in the context of Provision Point Mechanisms (PPM). Our approach is original in that it combines both framing and provision point dimensions by comparing maintaining (taking from the public good) and creating (giving to the public good) contexts using Provision Point experiments. Consistent with previous findings, we find that individuals tend to be less cooperative in the maintaining frame than in the creating frame. Our results also show that the framing effects are stronger under a PPM than under a VCM and increase with the provision point level. These results may have important consequences for the management of environmental resources.