The theoretical literature on collusion in auctions suggests that the first-price mechanism can deter the formation of bidding rings. In equilibrium, collusive negotiations are either successful or are avoided altogether, hence such analysis neglects the effects of failed collusion attempts. In...

In first- and second-price private value auctions with sequential bidding, second movers may discover the first movers' bid. Equilibrium behavior in the first-price auction is mostly unaffected but there are multiple equilibria in the second-price auction. Consequently, comparative statics...

In experiments, people behave more cooperatively when they are aware of an external threat, while in the field, we observe surprisingly high levels of within - group cooperation in conflict situations such as civil wars. We provide an explanation for these phenomena. We introduce a model in...

Absentmindedness is a special case of imperfect recall which according to Piccione and Rubinstein (1997a) leads to time inconsistencies. Aumann, Hart and Perry (1997a) question their argument and show how dynamic inconsistencies can be resolved. The present paper explores this issue from a...

We report on an experiment using video technology to manipulate pre-play communication protocols in the lab and to study purely social effects of communication on donations and discrimination between potential receivers. The experimental design eliminates strategic factors by allowing two...

We experimentally test the social motives behind individual participation in intergroup conflict by manipulating the framing and symmetry of conflict. We find that behavior in conflict depends on whether one is harmed by actions perpetrated by the out-group, but not on one’s own influence on...

"Waste not want not" expresses our culture's aversion to waste. "I could have gotten the same thing for less" is a sentiment that can diminish pleasure in a transaction. We study people's willingness to "pay" to avoid this spoiler. In one scenario, participants imagined they were looking for a...

In experiments, people behave more cooperatively when they are aware of an external threat, while in the field, we observe surprisingly high levels of cooperation and altruism within groups in conflict situations such as civil wars. We provide an explanation for these phenomena. We introduce a...