Auctions with Signaling Concerns

We study a symmetric private value model with signaling, in which the auction outcome is used by an outside observer to infer the bidders’ types. We elicit conditions under which an essentially unique D1 equilibrium bidding function exists in four auction formats. We establish the revenue equivalence does not hold between these auction designs. This is because signaling affects differently the bidders’ incentives to overbid their types given the payment rule and in the presence – or not – of an increasing price clock. We show this boost more revenues in the second-price auction than in the English auction, and more in the English auction than the first-price and all-pay auctions. Applications are art auction houses and charity auctions.