James J. Anton and Dennis A. Yao
The Quarterly Journal of Economics 75: 681-707, May 1992
Abstract: We analyze split award procurement auctions in which a buyer divides full production between two suppliers or awards all production to a single supplier, and suppliers have private cost information. An intriguing feature of split awards is that the equilibrium bids are implicitly coordinated. Because a split award price is the sum of offered split prices, each supplier can unilaterally veto a split award by bidding very high for the split. The need to coordinate is reflected in a split price that does not vary with private information. We also explore conditions under which split award auctions may be preferred to winner-take-all auctions.