Two New Conditions Supporting the First-Order Approach to Multisignal Principal-Agent Problems
提出了两个新的多信号推广条件，用于证明道德风险委托代理问题中的一阶方法，并比较了这两种方法的优劣。
This paper presents simple new multi-signal generalizations of the two classic meth-ods used to justify the first-order approach to moral hazard principal-agent problems, and compares these two approaches with each other. The paper first discusses limita-tions of previous generalizations. It then uses a state-space formulation to obtain a new multi-signal generalization of the Jewitt (1988) conditions. Next, using the Mirrlees formulation, the paper obtains new multi-signal generalizations of the CDFC approach of Rogerson (1985) and Sinclair-Desgagne ́ (1994). Vector calculus methods are used to derive easy-to-check local conditions for our generalization of the CDFC. Finally, we argue that the Jewitt conditions may generalize more flexibly than the CDFC to the multi-signal case. This is because, with many signals, the principal can become very well informed about the agent’s action and, even in the one-signal case, the CDFC must fail when the signal becomes very accurate.