Consider a bilateral trade problem in which the buyer's valuation v and the seller's cost c are private information. Speci...cally, the buyer's valuation and the seller's cost are uniformly distributed on the unit square. After learning their respective valuations, the seller gets to make a single take-it-or-leave-it oer to the buyer. If the buyer accepts the oer, trade occurs at the seller's demand price, and if the buyer rejects the oer no trade occurs