Bilateral Trading as an Efficient Auction over Time
A market composed of pairwise trading under incomplete information is modeled in order to analyze how resources are allocated among competing uses when information about trade gains is incomplete. Contrary to the results from studying a single such trade, sufficient homogeneity across potential trades guarantees that efficiency obtains. This is analogous to simple first-price auctions with homogeneous bidders, where bidders have a common bid function and, as a result, the high bidder also places the highest value on the auctioned object. With enough symmetry, the decentralized bilateral trades in the present model occur as if they were made in a first-price auction that occurs through time. The robustness of the efficiency result to heterogeneities among agents and to nontrivial search intensity decisions is then considered.