CHARITY AUCTIONS∗

In a charity auction the public-goods nature of auction revenue affects bidding incentives. We compare equilibrium bidding and revenue in first-price, secondprice, and all-pay charity auctions. Bidding revenue typically varies by selling format. First-price auctions are less lucrative than second-price and all-pay auctions, and with sufficiently many bidders the all-pay auction has the highest bidding revenue. However, revenue equivalence applies when the auctioneer can set a reserve price and fees plus threaten to cancel the auction. If the auctioneer cannot threaten cancellation, a reserve and bidding fee can augment revenue but again revenue varies by auction format