Free Riders and Cooperators in Public Goods Experiments: Can Evolutionary Dynamics Explain their Coexistence (original) (raw)
Related papers
2003
We explore by purely experimental means a heterogeneous agents scenario in experimental public goods games, assuming the existence of at least three types of player: free riders, cooperators, and reciprocators. We identify the various types by means of four classification methods, and then play the public goods game with homogeneous groups. We observe that (1) the average contribution level is enhanced in this setting; (2) the decay phenomenon is replicated in groups of ‘pure ’ free riders, whereas in groups of cooperative and reciprocating players the contribution is high and fairly stable throughout the game.
Heterogeneous Agents in Public Goods Experiments
2005
We explore by purely experimental means a heterogeneous agents scenario in experimental public goods games, assuming the existence of at least three types of player: free riders, cooperators, and reciprocators. We identify the various types by means of four classification methods, and then play the public goods game with homogeneous groups. We observe that (1) the average contribution level is enhanced in this setting; (2) the decay phenomenon is replicated in groups of 'pure' free riders, whereas in groups of cooperative and reciprocating players the contribution is high and fairly stable throughout the game.
Motives for Giving: A Reanalysis of Two Classic Public Goods Experiments
Southern Economic Journal, 2010
In laboratory public goods experiments, subjects make decisions about how much of a fixed endowment to contribute to the production of a public good in a sequence of periods. The nature of subjects' responses to information about others' decisions can help distinguish between alternative motives for giving, such as altruism, warm glow, reciprocity and inequality aversion. In this paper we reanalyze two published experimental studies of public goods and focus on the nature individuals' responses to others' behavior. We find economically and statistically significant dynamic interactions among subjects. The dynamic patterns indicate support for reciprocity and inequality aversion motives, but little for altruism and warm glow. We also conclude that individual-level analysis of existing public goods data can provide more insightful, informative estimates of treatment effects on behavior. Finally, we cast doubt on the notion that random rematching of subjects can induce statistical or strategic independence across decision periods.
Proceedings of the National Academy of Sciences, 2010
The results of numerous economic games suggest that humans behave more cooperatively than would be expected if they were maximizing selfish interests. It has been argued that this is because individuals gain satisfaction from the success of others, and that such prosocial preferences require a novel evolutionary explanation. However, in previous games, imperfect behavior would automatically lead to an increase in cooperation, making it impossible to decouple any form of mistake or error from prosocial cooperative decisions. Here we empirically test between these alternatives by decoupling imperfect behavior from prosocial preferences in modified versions of the public goods game, in which individuals would maximize their selfish gain by completely (100%) cooperating. We found that, although this led to higher levels of cooperation, it did not lead to full cooperation, and individuals still perceived their group mates as competitors. This is inconsistent with either selfish or prosocial preferences, suggesting that the most parsimonious explanation is imperfect behavior triggered by psychological drives that can prevent both complete defection and complete cooperation. More generally, our results illustrate the caution that must be exercised when interpreting the evolutionary implications of economic experiments, especially the absolute level of cooperation in a particular treatment. altruism | economic games | inclusive fitness | psychological drives | utility T here is a large empirical literature suggesting that when humans play anonymous one-shot economic games, they cooperate more than would be expected if they were purely self-interested (1-4). A common example comes from the public goods game, in which individuals are arranged in groups of N members, and each is given some quantity of monetary units that they can contribute to a public project. The contributions of all members are summed and multiplied by b (where b > 1), then equally divided between the group members. As long as n > b, an individual will always gain a higher economic reward in the short term by restricting or withholding their own contributions to the public project, while still benefiting from the contributions made by others. Although this favors zero contribution, individuals still contribute to the public project, and although they contribute less over time, ≈10% of individuals continue to contribute in the long run (1).
Evolution of conditional cooperation in public good games
Royal Society Open Science
Cooperation declines in repeated public good games because individuals behave as conditional cooperators. This is because individuals imitate the social behaviour of successful individuals when their payoff information is available. However, in human societies, individuals cooperate in many situations involving social dilemmas. We hypothesize that humans are sensitive to both success (payoffs) and how that success was obtained, by cheating (not socially sanctioned) or good behaviour (socially sanctioned and adds to prestige or reputation), when information is available about payoffs and prestige. We propose and model a repeated public good game with heterogeneous conditional cooperators where an agent's donation in a public goods game depends on comparing the number of donations in the population in the previous round and with the agent's arbitrary chosen conditional cooperative criterion. Such individuals imitate the social behaviour of role models based on their payoffs an...
Rewards and the evolution of cooperation in public good games
Biology Letters, 2014
Properly coordinating cooperation is relevant for resolving public good problems, such as clean energy and environmental protection. However, little is known about how individuals can coordinate themselves for a certain level of cooperation in large populations of strangers. In a typical situation, a consensus-building process rarely succeeds, owing to a lack of face and standing. The evolution of cooperation in this type of situation is studied here using threshold public good games, in which cooperation prevails when it is initially sufficient, or otherwise it perishes. While punishment is a powerful tool for shaping human behaviours, institutional punishment is often too costly to start with only a few contributors, which is another coordination problem. Here, we show that whatever the initial conditions, reward funds based on voluntary contribution can evolve. The voluntary reward paves the way for effectively overcoming the coordination problem and efficiently transforms freelo...
Contests over Public Goods: Evolutionary Stability and the Free-Rider Problem
We analyze group contests for public goods by applying the solution concept of an evolutionary stable strategy (ESS). We show that a global ESS cannot exist, because a mutant free-rider can always invade group behavior succesfully. There does exist, however, a unique local ESS, which we identify with evolutionary equilibrium. It coincides with Nash equilibrium, the hitherto dominant solution concept in contest theory, if and only if groups are symmetric. For asymmetric groups it always proposes a different and arguably more sensible solution than Nash equilibrium. We explore the properties of (local) ESS in detail.
standard attempts to explain the phenomenon of decaying contribution in repeated linear public goods games are based on a ‘representative agent’ approach, with either selfish or altruist agents and an ‘error’ component. In this paper we try to test by purely experimental means the alternative hypothesis that in experimental public goods games there are at least three types of player: free riders, cooperators, and reciprocators. We try to identify the various types by means of four classification methods, and then play the public goods game with homogeneous groups. We observe that (1) the average contribution level is enhanced in this setting; (2) the decay phenomenon is replicated in groups of ‘pure’ free riders, whereas in groups of cooperative and reciprocating players the contribution is high and fairly stable throughout the game.