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Fragility and robust design of optimal auctions

We consider the fragility problem of optimal auctions under a general class of preference relations and type spaces. We show that in generic settings feasibility of optimal auctions relies on the principals exact knowledge of the preference relations of the bidders. In the absence of such exact knowledge, a self-interested bidder will find it profitable to either misreport her private information or not participate at the auction. This phenomenon is a manifestation of fragility. Given this limitation we design auctions that are robust to model misspecification by leveraging tools from robust optimization, while maintaining computational tractability.