Comparative Statics and Welfare in Heterogeneous All-Pay Auctions: Bribes, Caps, and Performance Thresholds

Comparative statics for all-pay auctions with two heterogeneous and privately informed bidders are analyzed. General results are provided for when one bidder becomes stochastically weaker. The comparative statics are fully characterized for truncations. Moreover, we show that expected revenue may increase when one bidder weakens. In the second part of the paper we consider a dynamic contest in which beliefs change endogenously: the first bidder may preempt the auction by paying a bribe. An all-pay auction is held if the bribe is not paid, in which case the second bidder revises his beliefs. With the option to bribe, expected payoff decreases for a set of types of at least one bidder, possibly the bidder ostensibly advantaged by the preemption option. However, the expected revenue and the ex ante payoff of both bidders may improve.