Working Paper: CEPR ID: DP12482
Authors: Ricardo Alonso; Odilon Camara
Abstract: We consider a persuasion model in which a sender influences the actions of a receiver by selecting an experiment (public signal) from a set of feasible experiments. We ask: does the sender benefit from becoming an expert — observing a private signal prior to her selection? We provide necessary and sufficient conditions for a sender to never gain by becoming informed. Our key condition (sequential redundancy) shows that the informativeness of public experiments can substitute for the sender’s expertise. We then provide conditions for private information to strictly benefit or strictly hurt the sender. Expertise is beneficial when the sender values the ability to change her experimental choice according to her private information. When the sender does not gain from expertise, she is strictly hurt when di↵erent types cannot pool on an optimal experiment.
Keywords: Information Design; Bayesian Persuasion; Experts
JEL Codes: D83
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| private signal (Y70) | receiver's decision-making process (D79) |
| public experiments (C90) | sender's benefits from expertise (D83) |
| private signals are sequentially redundant (C69) | sender cannot benefit from becoming informed (D82) |
| sender observes private signal (Y70) | sender's chances of influencing receiver's actions (G41) |
| sender's choice of experiment based on private information (D82) | sender's benefits from expertise (D83) |
| sender cannot pool on optimal experiment (C90) | expertise can strictly hurt sender (D82) |