I study the properties of optimal long-term contracts in an environment in which the agent's type evolves stochastically over time. The model stylizes a buyer-seller relationship but the results apply quite naturally to many contractual situations including regulation and optimal...

We show that, in environments with independent private values and transferable utility, a privately informed principal can implement a contract that is ex-ante optimal for her. As an application, we consider a bilateral exchange environment (Myerson and Satterthwaite, 1983) in which the...