Mediated (Anti)Persuasive Communication

Can an information intermediary mitigate the harmful effect of persuasive communication? How does her success depend on her private information? We modify Kamenica and Gentzkow’s (2011) Bayesian persuasion framework to accommodate a privately-informed intermediary representing the receiver’s interests. We construct a novel statistic, the Autarky Value of the Intermediary’s Private Information (AVIPI), which measures how much expected utility the receiver gains over direct communication if the intermediary only trusts her private information. Our main result shows that a strictly positive AVIPI is necessary and sufficient to mitigate persuasive communication. Finally, we study the sender-intermediary interaction and welfare consequences in different classes of equilibria