Standard Public Goods Game Research Articles

Effects of individual and collective decision rule on cooperation in public goods game

Research on public goods game has traditionally focused on studying the effects of punishment and reward in experimental settings, commonly known as standard games. However, these standard games often examine isolated interactions among individuals, leading to varying results based on factors such as the population studied, number of participants, and geographical context. Consequently, the understanding of cooperation evolution remains imprecise.To address this limitation, we are trying to generalize these experimental studies, we employ an agent-based model in this study to simulate interactions in public goods game and explore the influence of punishment and reward on the evolution of cooperation. Unlike standard games, evolutionary games offer a more comprehensive framework to capture and analyze a broader range of strategic interactions and behaviors.In our approach, we introduce two methods for applying punishment or reward: Individual Punishment or Reward and Collective Punishment or Reward. Under the first method, actors can individually reward or punish each other based on their contributions or free-riding behavior towards the collective good. In the second method, decisions for punishment or reward are made collectively after achieving a consensus or agreement among the members of the group. We provide a model for comparing Individual Decision Rule and Collective Decision Rule under punishment and reward, to study their effects on the evolution of contributions.Consistent with recent experimental findings, our results indicate that these mechanisms lead to a significant increase in contributions compared to the outcomes observed in standard public goods game. Additionally, we demonstrate the significant role of rewards in promoting contribution within public goods game.

Preferences for honesty can support cooperation

AbstractMany collective action problems are inherently linked to honesty. By deciding to behave honestly, people contribute to solving the collective action problem. We use a laboratory experiment from two sites (n = 331 and n = 319) to test whether honest preferences can drive cooperation and whether these preferences can be differentially activated by framing. Subjects participate in an asymmetric information variant of the public goods game in one of two treatments that vary only in their wording: The Contribution Frame uses a standard public good game framing, while in the Honesty Frame, words aimed to trigger honesty are used. We measure subjects' honesty in three ways using the (i) sender–receiver task, (ii) the die‐roll task, and (iii) self‐reported honesty levels and account for other‐regarding preferences and social norms to disentangle key alternative motives. We find that all three measures of honesty preferences robustly predict contributions, as do other‐regarding preferences and empirical expectations but not normative expectations. Additionally, honesty preferences predict contributions in the Honesty Frame but not in the Contribution Frame, although the difference between these is not consistently significant. Finally, we find no differences in average cooperation across the treatments.

God games: An experimental study of uncertainty, superstition, and cooperation

This paper uses a novel lab experiment to test claims about the origins and functions of religion. We modify the standard public goods game, adding a computer-based agent that adjusts earnings in ways that might depend on players' contributions. Our treatments employ three different descriptions of the adjustment process that loosely correspond to monotheistic, atheistic, and agnostic interpretations of the computer's role. The adjustments neither mask players' contributions nor magnify their impact. Yet players in all three adjustment treatments contribute much more than those who play the standard public goods game. Players' contributions and survey responses show that adjustments induce superstitions in all treatments, with the strongest superstitions appearing in the quasi-monotheistic treatment and the weakest in the quasi-atheistic treatment. Text-based communication raises contributions and strengthens coordination. But when paired with the quasi-monotheistic description, communication also promotes counterproductive quests for winning numbers.

Reputation and punishment sustain cooperation in the optional public goods game.

Cooperative behaviour has been extensively studied as a choice between cooperation and defection. However, the possibility to not participate is also frequently available. This type of problem can be studied through the optional public goods game. The introduction of the 'Loner' strategy' allows players to withdraw from the game, which leads to a cooperator-defector-loner cycle. While pro-social punishment can help increase cooperation, anti-social punishment-where defectors punish cooperators-causes its downfall in both experimental and theoretical studies. In this paper, we introduce social norms that allow agents to condition their behaviour to the reputation of their peers. We benchmark this with respect both to the standard optional public goods game and to the variant where all types of punishment are allowed. We find that a social norm imposing a more moderate reputational penalty for opting out than for defecting increases cooperation. When, besides reputation, punishment is also possible, the two mechanisms work synergically under all social norms that do not assign to loners a strictly worse reputation than to defectors. Under this latter set-up, the high levels of cooperation are sustained by conditional strategies, which largely reduce the use of pro-social punishment and almost completely eliminate anti-social punishment. This article is part of the theme issue 'The language of cooperation: reputation and honest signalling'.

The rise and fall of donation behavior through reputation

Unlike in the standard public goods game (PGG), real-life donors (e.g. to charities) rarely receive any direct benefits from their donation behaviors to a disaster area, but donations are always prevalent. This paper studies why donation behaviors are common and the factors that can influence their propagation. The interactions among individuals are divided into two phases, including all individuals independently making decisions about whether to donate (namely donation game) and playing prisoner's dilemma with their neighbors in a structured population. We first explore the evolution of donation behaviors in the aforementioned spatial games with four competing strategies. As expected, “extreme altruists” can hardly survive in the population with “extreme egoists” unless they become “shunners”, who decide whether to cooperate in the prisoner's dilemma on the basis of the reputation of their opponents. Given the complexity of the real world, we further study the evolution of a more complex six-strategy population with additional two peculiar strategies, “hypocrites” and “realists”. We have observed more complicated phase diagrams, and multiple discontinuous phase transitions as well as a variety of spontaneously formed three-strategy cyclic states. Through the analysis of the phases and spatial dynamics, we find that these two introduced strategies will have an adverse impact on the popularization of donation behaviors in their own ways under different circumstances.

Strike one hundred to educate one: Measuring the efficacy of collective sanctions experimentally.

In this paper, we test whether sanctions applied to an entire group on account of the free-riding of one of its members can promote group cooperation. To measure the efficiency of such collective sanctions, we conducted a lab experiment based on a standard public good game. The results show that, overall, collective sanctions are ineffective. Moreover, when subjects are able to punish their peers, the level of cooperation is lower in the regime of collective sanctions than under individual sanctions. Both outcomes can be explained by a general disapproval of the collective responsibility for an individual fault: in the post-experimental survey, an absolute majority evaluated such regimes as unfair. While collective sanctions are not an effective means for boosting group compliance, there are nevertheless two insights to be gained here. First, there are differences across genders: under collective sanctions, men's level of compliance is significantly higher than under individual sanctions, while the opposite is true for women. Second, there were intriguing differences in outcomes between the different regime types. Under collective sanctions, a person who is caught tends to comply in the future, at least in the short term. By contrast, under individual sanctions, an individual wrongdoer decreases his or her level of compliance in the next period.

Transparency, asymmetric information and cooperation

We inquire experimentally whether asymmetric information in competitive settings and competition per se influence individual social behaviour. Participants perform a task and are remunerated according to two schemes, a non-competitive and a competitive one, then they play a standard public goods game. In the first scheme participants earn a flat remuneration, in the other they are ranked according to their performance and remunerated accordingly. Information about ranking and income before the game is played varies across three different treatments. We find that competition per se does not affect the amount of contribution. The time spent to choose how much to contribute is negatively correlated with the decision of cooperating fully. The main result is that full information about the relative performance in the competitive environment enhances the cooperation, while partial information reduces it.

Conditional cooperator enhances institutional punishment in public goods game

The role of incentive institutions on promoting cooperation in public goods game (PGG) has attracted much attention. Theoretical studies based on Nash equilibrium analysis predict that the punishment effect is often stronger than the reward effect. Although this result is confirmed by empirical studies, subjects do not always play these rational strategies. Recent experiments indicate that most subjects in PGGs are conditional cooperators who tend to contribute the group average. In this paper, we consider PGGs with three types of subjects, namely, cooperators, defectors, and conditional cooperators. Evolutionary game method is applied to investigate how conditional cooperators affect the effectiveness of different types of incentives. Overall, having conditional cooperators cannot lead to a higher contribution level in the standard PGG or the PGG with institutional rewards. However, they can enhance the effectiveness of institutional punishment, where a high contribution level can be maintained even for small punishments. As a consequence, in PGGs with conditional cooperators, punishment always leads to a higher contribution rate than do rewards. Numerical analysis indicates that this result is robust to errors in decision making.

Thankful or Thankless: Does the Past’s Altruism Increase the Present’s Public Good Contributions?

Two important aspects of global environmental problems are that (1) the actions of past generations affect the opportunities of the present, and (2) both in the past and the present generations, collaboration across different countries is needed to provide global public goods. In this paper, we study how these two aspects influence public good provisions by running simultaneous intercountry laboratory experiments using a modified public goods game in Denmark, Spain and Ghana. While the theoretical predictions of the modified public goods game do not differ from that of the standard public goods game, our experimental results show otherwise. Pooling across results from our Danish, Spanish and Ghanaian participants, we find that present-generation individuals contribute a higher percentage of their endowments when they have better institutions and a lower percentage of their endowments when they have higher endowments. We also find that present-generation individuals contribute less to transnational public goods only when their initial conditions have not been affected by past-generation contributions.

Coordination and Free-Riding Problems in Blood Donations

This article theoretically and experimentally examines the twin problems of free-riding and coordination failure faced by blood banks, by investigating the effects of information provision on the efficiency of blood donation. We augment a standard linear public goods game, incorporating the following features of blood donation: multiplicity of public goods (to reflect intertemporal coordination issues), current and upcoming upper bound demands (to incorporate the perishable nature of blood and the embargo period of consecutive donations), and semi-binary choices (to account for individual options to withhold donations or make donations and when). We analyze whether a provision of deterministic information on the potential blood demand (full information) would improve the efficiency of blood when compared to the provision of probabilistic information (partial information). The theory predicts that if each individual maximizes the payoff-sum of all players, then the full information provision would achieve efficiency in equilibrium. The results of laboratory experiment show that the full information provision does not improve the efficiency of donation, on an average. We find that full information improves intertemporal coordination, but it worsens the free-riding problem. Although information helps individuals to direct donations in response to the demand, it drives individuals to withhold donations to avoid potential wastage against the risk of over the upper bound. When the predicted total demand is relatively small, that is, when strategic uncertainty about others’ matters for achieving efficiency, the provision of information about intertemporal demand in upper bounds tends to lower efficiency because the donation withholding'' effect becomes dominant.

Let the others do the job: Comparing public good contribution behavior in the lab and in the field

Laboratory experiments provide convincing evidence that many people cooperate even if incentives to free-ride on the contributions of others are present. It is, however, unclear to what extent behavior observed in such a context-free environment is informative about behavior in context-rich field settings. Our study sheds light on this question by comparing students’ contributions to a standard public good game (PGG) with their contributions to a naturally occurring public good, a university course group assignment. Using a within-subject design, we find that students who contribute little in an unconditional PGG are also significantly more likely to free-ride on their peers in the group assignment. As an extension to previous studies, we also consider conditional contribution behavior. We observe that students who are classified as conditional cooperators in the online game also adjust their contributions to the behavior of others in the field. Our results, which are robust to the inclusion of a variety of contextual variables and the use of charitable giving as an alternative outcome measure, suggest that preferences revealed in the lab are informative for strategically comparable field settings. Yet, decision-making in the field is also strongly shaped by situational influences that challenge a direct comparison.

Free-rider Problem in Classroom Games - Impact of Gender and Intergroup Conditions

Behavioural experiments in the field of provision of public goods (including free rider problem) help to uncover the underlying processes and forces determining the nature of economy in the public sector. The objective of this paper is to determine the impact of gender and intergroup conditions on the extent of cooperation in standard linear public goods game using the voluntary contribution mechanism. Design of the teaching experiment is based on the methodology of Špalek (2011) with some modification. There were 80 undergraduate students of business participating in the classroom game, age range 20–22 years. Students were divided into three independent groups by 26 to 27 participants. Each group was playing independently, and individual strategies were recorded. We used the nonparametric tests (Mann‑Whitney U test and Kruskal‑Wallis Test) to analyse the differences between the gender and groups. Findings do not show statistically significant difference based on gender. On the other hand, the intergroup conditions determined by the social dynamics and discussion have significant influence on the distribution of goods. Results bring strong evidence on the importance of social and political factors influencing the pro‑social behaviour in the society.

Rewards and cooperation in social dilemma games

Rewards are identified as a mechanism to sustain cooperation in standard Public Good games, but have been found less effective in Common Pool Resource games. Both paradigms are important for environmental and resource economics as they capture the essence of real-world environmental and resource problems – the provision of pure public goods, and overextraction of common pool resources. This paper aims to understand why rewards are effective in one paradigm and not in the other. We hypothesize that this is because of an important difference between the two; the marginal per capita return is uncertain in the Common Pool Resource game because subjects can undo cooperative actions of others. This is just one of many differences between the two paradigms and hence we test our Hypothesis by introducing the option to reward in the Claim game, a game identical to the standard public good game except that it allows for both giving and taking. This feature causes the marginal per capita return to be uncertain. We find that while rewards are effective in sustaining cooperation in the Public Good game, they are much less effective in the Claim game. We identify the underlying mechanism causing this differential impact.

Threat and parochialism in intergroup relations: lab-in-the-field evidence from rural Georgia.

Competition between groups is widely considered to foster cooperation within groups. Evidence from laboratory experiments hints at the existence of a proximate mechanism by which humans increase their level of cooperation with their ingroup when faced with an external threat. Further work suggests that ingroup cooperation should go along with aggressive behaviour towards the outgroup, although these theories are at odds with others that see high investments in outgroup relations as important means of stabilizing intergroup relations. Surprisingly, few of these arguments have been tested in the field, and existing studies are also limited by the lack of a direct measure of threat perception and aggressive behaviour. This study presents lab-in-the-field results from a rural context where exposure to an ethnic outgroup varies between villages. This context makes it possible to capture levels of threat perception, aggressive behaviour and cooperation without inducing intergroup competition artificially in the laboratory. All concepts are measured behaviourally. In- and outgroup cooperation was measured with a standard public goods game, and a novel experimental protocol was developed that measures perceived threat and aggressive behaviour: the threat game. The results show that levels of perceived threat, ingroup cooperation and aggressive behaviour are higher in regions more strongly exposed to ethnic outsiders. However, exposed regions also show high levels of outgroup cooperation and a concomitant lack of elevated ingroup bias. This pattern is explained by theorizing that communities show parochial altruism when faced with an ethnic outgroup, but balance aggressive behaviour with cooperative offers to diffuse tensions and to keep open channels of mutually beneficial exchange.

Conflict technology in cooperation: The group size paradox revisited

This paper studies the implications of punishment‐induced conflict in a public goods game. It shows, under plausible assumptions, how larger group size sometimes enhances punishing behavior in social dilemmas and hence supports higher levels of cooperation. Unlike existing approaches that focus on uncoordinated punishment, I consider punishment as a coordinated activity that may be resisted by those being punished and study the implications of punishment‐induced conflict situations. Developing a conflict model of punishment and combining it with a standard public good game, I show that coordinated punishment can yield the concentration effect of punishment, leading to a larger group advantage; that is, the larger the group, the easier it becomes to organize cooperation. The key idea is that when punishers coordinate their punishment, punishers as a coalition successfullydividedefectors andpunisheach defector one by one. Surprisingly, even when coordination among punishers decays as group size increases, as long as the rate of decaying remains relatively slow the larger group advantage still obtains.

Conditional cooperation in network public goods experiments

This study investigates the pattern of contribution decisions in a network public goods game. In this game, each player’s payoff depends only on his own contribution and the contributions of his immediate neighbors in a circle network. As in the standard public goods game, we find substantial heterogeneity in behavior across subjects, including both unconditional free-riding and full cooperation, as well as conditional cooperation. We first examine the impact of different information conditions on conditional cooperation. At the aggregate level, we find that players who observe average payoff information about others contribute significantly less than those who observe average contribution information. We then investigate the extent to which conditional cooperators facilitate the spread of cooperation and free-riding behavior across the network. In groups with a single free-rider type, we show that individual contributions decay faster for players who are closer in the network to the free rider. On the other hand, in groups with a single unconditional full contributor type, players do not respond by converging to full cooperation. Instead, we find that proximity to the unconditional full contributor seems only to mitigate (or delay) the typical decline in contributions over time. These contrasting effects are consistent with the widespread claim that conditional cooperation is imperfect, or exhibits a self-serving bias.

Group-Level Selection Increases Cooperation in the Public Goods Game.

When groups compete for resources, some groups will be more successful than others, forcing out less successful groups. Group-level selection is the most extreme form of group competition, where the weaker group ceases to exist, becoming extinct. We implement group-level selection in a controlled laboratory experiment in order to study its impact on human cooperation. The experiment uses variations on the standard linear public goods game. Group-level selection operates through competition for survival: the least successful, lowest-earning groups become extinct, in the sense that they no longer are able to play the game. Additional control treatments include group comparison without extinction, and extinction of the least successful individuals across groups. We find that group-level extinction produces very high contributions to the provision of the public good, while group comparison alone or individual extinction fail to cause higher contributions. Our results provide stark evidence that group-level selection enhances within-group cooperation.

Indirect Reciprocity, Resource Sharing, and Environmental Risk: Evidence from Field Experiments in Siberia.

Integrating information from existing research, qualitative ethnographic interviews, and participant observation, we designed a field experiment that introduces idiosyncratic environmental risk and a voluntary sharing decision into a standard public goods game. Conducted with subsistence resource users in rural villages on the Kamchatka Peninsula in Northeast Siberia, we find evidence consistent with a model of indirect reciprocity and local social norms of helping the needy. When participants are allowed to develop reputations in the experiments, as is the case in most small-scale societies, we find that sharing is increasingly directed toward individuals experiencing hardship, good reputations increase aid, and the pooling of resources through voluntary sharing becomes more effective. We also find high levels of voluntary sharing without a strong commitment device; however, this form of cooperation does not increase contributions to the public good. Our results are consistent with previous experiments and theoretical models, suggesting strategic risks tied to rewards, punishments, and reputations are important. However, unlike studies that focus solely on strategic risks, we find the effects of rewards, punishments, and reputations are altered by the presence of environmental factors. Unexpected changes in resource abundance increase interdependence and may alter the costs and benefits of cooperation, relative to defection. We suggest environmental factors that increase interdependence are critically important to consider when developing and testing theories of cooperation

Leadership and Incentives

We study how leader compensation affects public goods provision. We report from a lab experiment with four treatments, where the base treatment was a standard public goods game with simultaneous contribution decisions, and the three other treatments allowed participants to volunteer to be the leader in their group and make their contribution before the others. In the three leader treatments, we manipulated the level of compensation given to the leader. Our main finding is that a moderate compensation to the leader is beneficial; it increases the average contribution relative to both a situation where the leader is not compensated and a situation without a leader. A further increase in the leader compensation, however, is detrimental to public goods provision; it attracts more free riders and creates a social crowding-out effect. Finally, we report from a survey showing that the social crowding-out effect is also present in the population at large. We argue that the main findings of the paper are important in many real-life settings where we would like to use economic incentives to encourage people to lead by example. This paper was accepted by Uri Gneezy, behavioral economics.

Second-party and third-party punishment in a public goods experiment

ABSTRACTWe experimentally investigate whether third-party punishment is more effective than second-party punishment to increase public goods contribution. In our experiment, third parties first played the standard public goods game and then made punishment decisions as independent bystanders. We find that third parties punished more frequently, severely and less antisocially, resulting in a higher contribution level than that driven by second-party punishment. The third party’s exaggerated emotion towards free riders is proposed to explain their superior punishment effectiveness.