Victorious alliances often fight about the spoils of war. We consider experimentally when members of victorious alliances accept a peaceful division of the spoils, and when they fight against each other, and how the inability to commit to a peaceful division affects their effort contributions in...

We consider a voluntary contributions game, in which players may punish others after contributions are made and observed. The productivity of contributions, as captured in the marginal-per-capita return, differs among individuals, so that there are two types: high and low productivity. Every two...

We introduce "group cohesion" to study the economic relevance of social relationships in team production. We operationalize measurement of group cohesion, adapting the "oneness scale" from psychology. A series of experiments, including a pre-registered replication, reveals strong positive...