A novel version of a Voluntary Contribution Mechanism game tests how player cooperation responds to changes in incentives, i.e., payoffs that depend on performance relative to different reference groups. Cooperation is greatest when players are competing against players in other four-person...

We analyze communication about the social returns to investment in a public good. We model two agents who have private information about these returns as well as their own taste for cooperation, or social preferences. Before deciding to contribute or not, each agent submits an unverifiable...

We test whether a descriptive norm-nudge is a suitable policy tool to increase cooperation in a social dilemma when decisions are taken by teams, not individuals. 10 Each team in our experiment comes from a different fishing boat at Lake Victoria, Tanzania. The provision of a norm-nudge is...

There are situations in which competitors ally to pursue a common objective. This simultaneous presence of cooperation and competition is called coopetition and we study it theoretically and experimentally in a group contest setup. More concretely, we analyze a group contest with a new sharing...

We study the stability of voluntary cooperation in response to varying rates at which a group grows. Using a laboratory public-good game with voluntary contributions and economies of scale, we construct a situation in which expanding a group's size yields potential efficiency gains, but only if...

We analyze an experimental public goods game in which group members can endogenously determine whether they want to supplement a standard voluntary contribution mechanism with the possibility of rewarding or punishing other group members. We find a large and positive effect of endogenous...

We use an experiment to test the hypothesis that groups consisting of like-minded cooperators are able to cooperate irrespective of punishment and therefore have a lower demand for a costly punishment institution than groups of like-minded free riders, who are unable to cooperate without...

We consider how group size affects the private provision of a public good with non-refundable binary contributions. A fixed amount of the good is provided if and only if the number of contributors reaches an exogenous threshold. The threshold, the group size, and the identical, non-refundable...

Under the standard summation technology, pure public goods can be provided via the direct contributions mechanism, even in an arbitrarily large group. However, if the public good exhibits any degree of rivalry, individual consumption of the public good will fall to zero as group size grows...

Morgan (2000) has shown that lotteries are potentially an effective mechanism for the provision of public goods. In particular, he has shown that lotteries lead to a level of provision above the level provided by the voluntary contributions mechanism. In this paper, we analyze the effect of...