Persuasion with Coarse Communication (opens in new tab)

In many expert-decision maker settings, information is richer than the language used to convey it. Motivated by this communication friction, we study Bayesian persuasion when the sender is constrained to use $k$ messages. We show that the sender's value is given by a $k$-point analogue of concavification, which we call $k$-concavification. An optimal information structure can be chosen with affinely independent posterior support, allowing the ...