Development of human societies requires cooperation among unrelated individuals and obedience to social norms. Although punishment is widely agreed to be potentially useful in fostering cooperation, many recent results in psychology and economics highlight punishments' failures in this regard....

Using a negatively framed public good game, we study the cooperative behavior of individuals who reintegrate their group after being excluded by their peers. We manipulate the length of exclusion and whether this length is imposed exogenously or results from a vote. We show that people are...

In public good provision, privileged groups enjoy the advantage that some of its members find it optimal to supply a positive amount of the public good. However, their inherent asymmetric nature may make the enforcement of cooperative behavior through informal sanctioning harder to accomplish....

Many important intertemporal decisions are made by groups rather than individuals. What happens to collective decisions when there is internal conflict about the tradeoff between present and future has not been thoroughly investigated so far. We study experimentally the causal effect of group...

Economic and social interaction takes place between individuals with heterogeneous characteristics. We investigate experimentally the emergence and informal enforcement of different contribution norms to a public good in homogeneous and different heterogeneous groups. When punishment is not...