Simultaneous Auctions with Synergies

Motivated by recent auctions of licenses for the radio frequency spec trum, we consider situations where multiple objects are auctioned simultaneousl y by means of a second-price, sealed-bid auction. For some buyers, called globa l bidders, the value of multiple objects exceeds the sum of the objects' values separately. Others, called local bidders, are interested in only one object. I n a simple independent private values setting, we (a) characterize an equilibri um that is symmetric among the global bidders; (b) show that the addition of bi dders often leads to less aggressive bidding; and (c) compare the revenues obta ined from the simultaneous auction to those from its sequential counterpart.