Unmediated talk under incomplete information

Résumé

We show the role of unmediated plain conversation as both an information transmission and a coordination device for the class of two-player incomplete information games. Concretely, we proove that any communication equilibrium payoff of such games can be reached as a Nash equilibrium payoff of the game extended by a two phase (exante and interim) unmediated communication protocol. This protocol is constructed by using communicative one-way functions, which are, in turn, designed with the help of modern cryptographic tools. A familiar context in which our results could be applied is bilateral trading with incomplete information.