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,...

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 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...

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...