Generalized agency and limited liability.

Summary This thesis considers generalized agency problems: situations in which the principal faces both an adverse selection and a moral hazard problem. There are two reasons why the principal uses an agent: the agent may have private information that the principal does not observe and the agent may have the power to make decisions that the principal does not directly control. Although most of the literature on incentives treats adverse selection and moral hazard situations separately, these two important features are at work together in a wide variety of economic environments. This thesis is part of a body of work that analyzes how the two types of informational asymmetry interact from two different perspectives. On the one hand, we know that the results on the characterization and existence of optimal contracts, derived from the literature dealing separately with adverse selection and moral hazard, are not directly transposable to a generalized agency framework. The first objective of this thesis is to define a set of sufficient conditions that validate the use of the first order approach. On the other hand, considering the presence of a pre- and post-contractual opportunism problem, the second objective of this thesis is to analyze the way the principal constructs the contract, so as to limit the consequences of both types of informational asymmetry.