Incentives in core-selecting auctions with single-minded bidders

This paper considers some package auctions with known single-minded bidders. A single-minded bidder is interested in a unique bundle of goods and bids only for that bundle. We examine each bidder's incentive in Ausubel and Milgrom's (2002) ascending proxy auction and every bidder-optimal core-selecting auction. We provide a simple condition for each bidder to report his valuation truthfully, which can be expressed in a single sentence--any "rival" of my "rivals" is my "rival." The Vickrey outcome lies in the core if and only if this condition holds for every bidder; however, it is rarely satisfied.Package auction Core-selecting auction Ascending proxy auction Single-minded bidder