Threshold Public Goods Game Research Articles

Beneficial laggards: multilevel selection, cooperative polymorphism and division of labour in threshold public good games

BackgroundThe origin and stability of cooperation is a hot topic in social and behavioural sciences. A complicated conundrum exists as defectors have an advantage over cooperators, whenever cooperation is costly so consequently, not cooperating pays off. In addition, the discovery that humans and some animal populations, such as lions, are polymorphic, where cooperators and defectors stably live together -- while defectors are not being punished--, is even more puzzling. Here we offer a novel explanation based on a Threshold Public Good Game (PGG) that includes the interaction of individual and group level selection, where individuals can contribute to multiple collective actions, in our model group hunting and group defense.ResultsOur results show that there are polymorphic equilibria in Threshold PGGs; that multi-level selection does not select for the most cooperators per group but selects those close to the optimum number of cooperators (in terms of the Threshold PGG). In particular for medium cost values division of labour evolves within the group with regard to the two types of cooperative actions (hunting vs. defense). Moreover we show evidence that spatial population structure promotes cooperation in multiple PGGs. We also demonstrate that these results apply for a wide range of non-linear benefit function types.ConclusionsWe demonstrate that cooperation can be stable in Threshold PGG, even when the proportion of so called free riders is high in the population. A fundamentally new mechanism is proposed how laggards, individuals that have a high tendency to defect during one specific group action can actually contribute to the fitness of the group, by playing part in an optimal resource allocation in Threshold Public Good Games. In general, our results show that acknowledging a multilevel selection process will open up novel explanations for collective actions.

Coordinating to Protect the Global Climate: Experimental Evidence on the Role of Inequality and Commitment

Free riding and coordination difficulties are held to be the primary causes of cooperation breakdown among nonrelatives. These thwarting effects are particularly severe in the absence of effective monitoring institutions capable of sanctioning deviant behavior. Unfortunately, solutions to global environmental dilemmas, like climate change, cannot depend on coercion mechanisms, given the transnational effects of emissions. A further complication is that it yields “common but differentiated responsibilities”. Such asymmetries in wealth and carbon responsibilities among the actors, and the ensuing issues of equity, might further impede cooperation. Yet, a growing literature stresses the importance of non-economic factors in explaining human behavior; therefore, instruments that go beyond the traditional incentives might prove effective in facilitating the task. Given the empirical nature of the problem, we address it by means of a controlled laboratory experiment: a framed threshold public goods game is used to investigate the degree of cooperation and coordination achieved by groups of six participants in combating simulated catastrophic climate change. While necessarily simple for the sake of tractability, the game is designed to incorporate key real-world issues, such as inequity and the impact of emergent institutions based on nonbinding “pledge and review” mechanisms.

Emergence of social cooperation in threshold public goods games with collective risk

In real situations, people are often faced with the option of voluntary contribution to achieve a collective goal, for example, building a dam or a fence, in order to avoid an unfavorable loss. Those who do not donate, however, can free ride on others' sacrifices. As a result, cooperation is difficult to maintain, leading to an enduring collective-risk social dilemma. To address this issue, here we propose a simple yet effective theoretical model of threshold public goods game with collective risk and focus on the effect of risk on the emergence of social cooperation. To do this, we consider the population dynamics represented by replicator equation for two simplifying scenarios, respectively: one with fair sharers, who contribute the minimum average amount versus defectors and the other with altruists contributing more than average versus defectors. For both cases, we find that the dilemma is relieved in high-risk situations where cooperation is likely to persist and dominate defection in the population. Large initial endowment to individuals also encourages the risk-averse action, which means that, as compared to poor players (with small initial endowment), wealthy individuals (with large initial endowment) are more likely to cooperate in order to protect their private accounts. In addition, we show that small donation amount and small threshold (collective target) can encourage and sustain cooperation. Furthermore, for other parameters fixed, the impacts of group size act differently on the two scenarios because of distinct mechanisms: in the former case where the cost of cooperation depends on the group size, large size of group readily results in defection, while easily maintains cooperation in the latter case where the cost of cooperation is fixed irrespective of the group size. Our theoretical results of the replicator dynamics are in excellent agreement with the individual based simulation results.

Fairness and bargaining power in threshold public goods experiments

AbstractExperiments on three two‐person threshold public good provision games, namely, the simultaneous, sequential, and dictator games, are conducted to explore the motives behind giving. Players who move simultaneously are endowed with equal bargaining power, and players who move first are endowed with more bargaining power than players who move subsequently. Dictators are indubitably endowed with complete bargaining power. Since the differences between the bargaining powers of two players increase from the simultaneous to the sequential to the dictator game, comparisons among games allow us to trace whether the contribution behavior is motivated by fairness or is simply due to the strategic concern. The experimental evidence shows that the strategic concern explains the overall contribution behavior better than the motive of fairness. However, in the final round 26% of the dictators share the threshold evenly with their opponents, suggesting that some subjects do play fairly. Copyright © 2007 John Wiley & Sons, Ltd.

Cross-national gender differences in behavior in a threshold public goods game: Japan versus Canada

To investigate the effects of gender and national culture on economic behavior, we compare all-male and all-female groups from Japan and Canada in the context of a threshold public goods game with a strong free-riding equilibrium and many socially efficient threshold equilibria. Females and Canadians exhibit higher levels of conformity when compared with males and Japanese, respectively. However, such symmetric group behavior translates into significantly tighter equilibrium convergence only for Canadian females. Canadians, particularly Canadian females, are more successful at providing the public good than Japanese. The results suggest that the prevalence of different notions of self-construal may affect behavior.

Cross-National Gender Differences in Behavior in a Threshold Public Goods Game: Japan versus Canada

To investigate the effects of gender and national culture on economic behavior, we compare all-male and all-female groups from Japan and Canada in the context of a threshold public goods game with a strong free-riding equilibrium and many socially efficient threshold equilibria. Females and Canadians exhibit higher levels of conformity when compared with males and Japanese respectively. However, such symmetric group behavior translates into significantly tighter equilibrium convergence only for Canadian females. Canadians, particularly Canadian females, are more successful at providing the public good than Japanese. The results suggest that the prevalence of different notions of self-construal, may affect behavior.

Asset Markets and Equilibrium Selection in Public Goods Games with Provision Points: An Experimental Study

This paper reports the experimental results of implicit pre-play communication on the equilibrium selection in threshold public goods game experiments. The existence of an asset market in which the right to participate in a public goods game with a provision point is auctioned off among a larger group in a first stage is found to enhance significantly the contribution to the provision of the public good in a subsequent second stage. Though, contributions declined on average in the repeated public goods game when subjects were endowed with the right to play, they increased when subjects purchased the right to play. Once reached the Pareto-dominant equilibrium in the second stage, the auction price at the first stage increased to its upper limit. Confronted with the high entry cost which induced the dissipation of all possible gains from the public goods game single subjects deviated from the equilibrium strategy. Yet, robustness of the full contribution equilibrium is proved since unilateral deviations from it did neither reduce the individual contributions to the provision of the public good in the subsequent periods nor sustained a lower entry price.

Choosing between a socially efficient and free-riding equilibrium: Nurses versus economics and business students

Six groups of economics and business students and six groups of nurses each participated in a laboratory threshold public goods game. This game is consistent both with equilibria involving cooperative and an equilibrium involving non-cooperative behavior. This contrasts with other games in which economics and business students proved less cooperative than others in contexts consistent only with equilibria involving non-cooperative behavior. Nevertheless, in the threshold game, the students moved inexorably toward the strong free-riding equilibrium, cooperating far less than the nurses, who cycled around an efficient threshold equilibrium. Subject pool selection clearly affects equilibrium selection in the threshold framework.

Identifiability of Individual Contributions in a Threshold Public Goods Experiment

This paper experimentally examines how information affects behavior in a threshold public goods game. Three treatments investigate how subjects react to varying amounts of information about the contribution behavior of other group members. Results suggest that revealing anonymous information about others' contributions leads to a significant decrease in contributions and an increase in the variance of contributions. In contrast, when individual contributions are identified by subject number, average contributions increase and the variance of contributions decreases significantly.

Gender and free riding in a threshold public goods game: Experimental evidence

This paper examines experimentally the effect of gender on contributions in a threshold public good framework which permits both strong free-riding and cooperative threshold equilibria. Subjects are recruited from a randomly selected sample of students. Females initially contribute significantly more than males, but significance vanishes as the game evolves. However, female groups are significantly better able to coordinate around a selected equilibrium. Such coordination does not imply greater efficiency at avoiding wasteful contributions. It does seem related to a tendency of females to behave more like each other throughout the game. Results are compared with the continuous provision framework.