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...

In repeated games, it is hard to distinguish true prosocial behavior from strategic instrumental behavior. In particular, a player does not know whether a reciprocal action is intrinsically or instrumentally motivated. In this paper, we experimentally investigate the relationship between...

In some important multi-player situations, such as efforts to supply a global public good, players can choose the game they want to play. In this paper we conduct an experimental test of the decision to choose between a “tipping” game, in which every player wants to contribute to the public...

Extensive research in economics explores generosity in monetary allocations. However, generosity often involves the allocation of non-monetary goods or experiences. Existing evidence suggests that generosity may be higher in such contexts, though no direct comparison exists. Here, we compare...