The condominium problem; auctions for substitutes

This paper considers the problem of designing selling procedures for substitutes (like condominium units). Oral, ascending auctions for the right to choose are efficient. This is a common type of auction used for the sale of real estate. Efficiency is not optimal from the seller’s viewpoint. An optimal procedure distorts the right-to-choose auction to favor in late rounds bidders whose preferred object has already been sold. This optimal auction is complex. A revenue improving departure from efficiency can be achieved by simply auctioning all the rights to choose before any of them is exerted.Received: 5 February 2003, Accepted: 15 February 2005, JEL Classification: D44I acknowledge very helpful comments by Joe Harrington, Ken Hendricks, and anonymous referees. Financial aid from the European Commission through the TMR Program (contract FMRX-CT98-0203) and the Spanish MCyT (Grants SEC 2002-02506 and SEC 2003-08080) is also gratefully acknowledged.