We consider multiple-principal multiple-agent models of moral hazard: principals compete through mechanisms in the presence of agents who take unobservable actions. In this context, we provide a rationale for restricting principals to make use of simple mechanisms, which correspond to direct...

A the present paper we show that messages may improve efficiency even in model of complete information. Messages are useful two main reasons. First, if the principal is not allowed to use stochastic mechanisms, mechanisms with messages can induced mixed strategies and hence indirectly a...

We provide two examples in a pure moral hazard setting with two principals and two agents. Example 1 shows that a strongly robust equilibrium in simple (direct) mechanisms can no longer be sustained as an equilibrium when a principal can deviate to an indirect communication scheme. Conversely,...

In this note we consider a basic property of common agency models: pure strategy equilibria of games where principals compete in direct mechanisms are robust to the possibility that principals might deviate and use more complex indirect mechanisms to design their contracts. We show that this...

In multiple principal, multiple agent models of moral hazard, we provide conditions under which the outcomes of equilibria in direct mechanisms are preserved when principals can offer indirect communication schemes. We discuss the role of random allocations and recommendations and relate the...

In multiple-principal multiple-agent models of moral hazard, we provide sufficient conditions for the outcomes of pure-strategy equilibria in direct mechanisms to be preserved when principals can offer indirect communication schemes. The conditions include strong robustness in the direct...

We consider multiple-principal multiple-agent models of moral hazard: principals compete through mechanisms in the presence of agents who take unobservable actions. In this context, we provide a rationale for restricting principals to make use of simple mechanisms, which correspond to direct...

In the present note, we show that a weak restriction on out of equilibrium beliefs allows to extend the Revelation Principle to exclusive agency games, even if we consider mixed strategy equilibria. Next, we argue that this result does not extend to games with several agents, even if we restrict...