Partnerships, lemons and efficient trade

We analyze the possibility of efficient trade with informationally interdependent valuations and with a dispersed ownership. A crucial role is played by the sign of the derivatives that measure how valuation functions depend on others’ signals. If valuations are increasing functions of other agents’ signals, it is more difficult to achieve efficient trade with interdependent values than with private values (where the respective derivatives are zero.) In contrast, if valuations are decreasing functions of other agents’ signals, it is easier to achieve efficient trade with interdependent values. Our results unify and generalize the insights of Cramton et al. [1987], Myerson and Satterthwaite [1983], and Akerlof [1970]