This paper identifies several social choice correspondences which are or are not fully implementable in economic environments when agents are incompletely informed about the environment. We show that in contrast to results in the case of complete information, neither efficient allocations nor core allocations define implementable social choice correspondences. We also identify conditions under which the Rational Expectations Equilibrium correspondence is implementable. We extend the concepts of fair allocations and Lindahl allocations to economies with incomplete information, and show that envy-free allocations and Lindahl allocations are implementable under some conditions while fair allocations are not.

In this paper, we analyze optimal contracts in an infinitely repeated agency model in which both the principal and agent discount the future. We show that there is a stationary representation of the optimal contract when the agent's conditional discounted expected utility is used as a state variable. This representation reduces the multi-period problem to a static variational problem which can be analyzed using standard variational techniques. This reduction is used to obtain several properties of the contract.