We define social reciprocity as the act of demonstrating one's disapproval, at some personal cost, for the violation of widely-held norms (e.g., don't free ride). Social reciprocity differs from standard notions of reciprocity because social reciprocators intervene whenever a norm is violated...

Auctions are a popular way to raise money for charities, but relatively little is known, either theoretically or empirically, about the properties of charity auctions. The small theoretical literature suggests that the all-pay auction should garner more money than winner-pay auctions. We conduct...

In many environments, tournaments can elicit more effort from workers, except perhaps when workers can sabotage each other. Because it is hard to separate effort, ability and output in many real workplace settings, the empirical evidence on the incentive effect of tournaments is thin. There is...