The Theory of Moral Hazard and Unobservable Behaviour: Part I
研究代理人行为不可观测时，委托人如何设计合同来近似最优结果，并指出用代理人一阶条件作为约束可能失效，给出更一般的拉格朗日条件。
Principal-agent models are studied, in which outcomes conditional on the agent's action are uncertain, and the agent's behaviour therefore unobservable. For a model with bounded agent's utility, conditions are given under which the first-best equilibrium can be approximated arbitrarily closely by contracts relating payment to observable outcomes. For general models, it is shown that the solution may not always be obtained by using the agent's first-order conditions as constraint. General conditions of Lagrangean type are given for problems in which contracts are finite-dimensional.