We study the stability of voluntary cooperation in response to varying group growth rates. Using a laboratory public-good game, we construct a situation where increasing group size yields potential efficiency gains, but only with sustained cooperation. We then study the effect of exogenously...

We study network formation with n players and link cost α 0. After the network is built, an adversary randomly deletes one link according to a certain probability distribution. Cost for player ν incorporates the expected number of players to which ν will become disconnected. We focus on...

We study how the willingness to enter long-term bilateral relationships affects cooperation even when parties have little information about each other, ex ante, and cooperation is otherwise unenforceable. We experimentally investigate a finitely-repeated Prisoner's Dilemma, allowing players to...

Higher-dimensional symmetric games become of more and more importance for applied micro- and macroeconomic research. Standard approaches to uniqueness of equilibria have the drawback that they are restrictive or not easy to evaluate analytically. In this paper I provide some general but...

Efficient growth often requires the integration of individuals from lower-performing groups, firms, or societies into higher-performing ones. Such integration may be difficult without facilitating interventions or restrictions. We explore, using a laboratory experiment, the effectiveness of two...

This paper examines whether and how cheap talk communication can facilitate within-group coordination when two unequal sized groups compete for a prize that is shared equally among members of the winning group, regardless of their (costly) contributions to the group's success. We find that...

We introduce intention-based social preferences into a Bayesian mechanism design framework. We first show that, under common knowledge of social preferences, any tension between material efficiency, incentive compatibility, and voluntary participation can be resolved. Hence, famous impossibility...

Any symmetric mixed-strategy equilibrium in a Tullock contest with intermediate values of the decisiveness parameter ("2 R ∞") has countably infinitely many mass points. All probability weight is concentrated on those mass points, which have the zero bid as their sole point of accumulation....

This paper studies a large class of imperfectly discriminating contests, referred to as elastic contests, that induce players to either overbid a standing bid or to abstain from bidding altogether. Many common forms of contest are elastic. In any equilibrium of an elastic contest, there is...

The paper generalizes Kuhn's Theorem to extensive form games in which players condition their play on the realization of ambiguous randomization devices and use a maxmin decision rule to evaluate the consequences of their decisions. It proves that ambiguous behavioral and ambiguous mixed...