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...

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...