Optimal sequential auctions

Sequential sealed rst-price and open ascending bid auctions are studied. We examine which auction rule achieves the low procurement cost. We show that the answer to this policy question depends on whether the items are com- plements or substitutes. With substitutes, the rst-price auction is preferred, while with complementarities, the open ascending bid auction is preferred. We also illustrate the procurement cost minimizing auction and the auction rule preferred by the bidders. With substitutes, bidders prefer the open ascending bid auction, while with complements bidders prefer the rst-price auction.