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...