Dynamic Auctions in Procurement

We study the theory and practical implementation of dynamic procurement auctions. We consider the procurement of many related items. With many related items, price discovery is important not only to reduce the winner’s curse, but more importantly, to simplify the bidder’s decision problem and to facilitate the revelation of preferences in the bids. Three auction formats are considered: simultaneous descending auctions are preferred if the items are not divisible, simultaneous clock auctions are desirable for procuring many divisible goods, and the clock-proxy auction is best if complementarities among items are strong and varied across the suppliers. We examine the properties of these auctions and discuss important practical considerations in applying them.