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 use experimental methods to investigate whether pledges of commitment can improve cooperation in endogenously formed partnerships facing a social dilemma. Treatments vary in terms of the individual's (a) opportunity to commit to their partner, (b) the cost of dissolving committed...

We use experimental methods to investigate whether pledges of commitment can improve cooperation in endogenously formed partnerships facing a social dilemma. Treatments vary in terms of the individual's (a) opportunity to commit to their partner, (b) the cost of dissolving committed...

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...