Ambiguous Persuasion: An Ex-Ante Formulation

Abstract

Consider a persuasion game where both the sender and receiver are ambiguity averse with maxmin expected utility (MEU) preferences and the sender can choose to design an ambiguous information structure. This paper studies the game with an ex-ante formulation: The sender first commits to a (possibly ambiguous) information structure and then the receiver best responds by choosing an ex-ante message-contingent action plan. Under this formulation, I show it is never strictly beneficial for the sender to use an ambiguous information structure as opposed to a standard (unambiguous) information structure. This result is shown to be robust to the receiver having non-MEU Uncertainty Averse preferences but not to the sender having non-MEU preferences.Comment: 19 page