Multiple teams and the volunteer’s dilemma

We study the volunteer’s dilemma if the set of possible volunteers is partitioned into small teams that can coordinate internally but not across teams. If coordination is costless, the aggregate equilibrium payoff is determined by the number of teams only. The team size is relevant for individual players’ payoffs. They prefer larger teams. The optimality of the team structure is also considered if the coordination cost in teams is an increasing and strictly convex function of team size. Such costs can make very large teams suboptimal. Also, such costs suggest a partitioning into teams of roughly equal size.