In two-person generosity games, the proposer’s agreement payoff is exogenously given, whereas that of the responder is endogenously determined by the proposer’s choice of the pie size. In three-person generosity games, equal agreement payoffs for two of the players are either exogenously...

When randomly assigning participants to experimental roles and the according payment prospects, participants seem to receive “manna from heaven.” In our view, this seriously questions the validity of laboratory findings. We depart from this by auctioning off player roles via the incentive...