We show in a public goods experiment on three continents that conditional cooperation is a universal behavioral regularity. Yet, the number of conditional cooperators and the extent of conditional cooperation are much higher in the U.S.A. than anywhere else. -- conditional cooperation ; public...

We analyze an experimental public goods game in which group members can endogenously determine whether they want to supplement a standard voluntary contribution mechanism with the possibility of rewarding or punishing other group members. We find a large and positive effect of endogenous...

We study the effects of leadership in the provision of public goods by examining (i) the relative importance of reward and punishment as leadership devices, (ii) whether endogenous leadership is more efficient than exogenously enforced leadership, and (iii) whether leaders contributing last,...