Bayesian Explanations for Persuasion

The central puzzle of persuasion is why a receiver would ever listen to a sender who they know is trying to change their beliefs or behavior. This paper provides a common formal framework for five approaches to solving this puzzle: (1) some messages are easier to send for those with favorable information (costly signaling), (2) the sender and receiver have partially aligned interests (cheap talk), (3) the sender messages can be checked (verifiable information), (4) the sender cares about perceptions of his competence/honesty (reputation concerns), and (5) the sender can “commit” to a messaging strategy (Bayesian Persuasion). To explore the relative value of these approaches, I discuss which provide insight into prominent empirical findings on campaigns, partisan media/propaganda, and lobbying. While models focusing on commitment have rapidly become one of the most common (if not the most common) theoretical approach to studying persuasion in political science and economics in the past decade, they are not particularly well-suited to explaining these phenomena.