Using Cheap Talk to Polarize or Unify a Group of Decision Makers

We develop a model of strategic information transmission from an expert with informational superiority to decision makers who vote on a proposal. We show that an expert's simple cheap talk strategy can be surprisingly effective in persuading decision makers by polarizing or unifying their opinions. After observing the expert's cheap talk message, decision makers may ignore their private information and vote according to the expert's interest, even though they know the expert has her own bias. In other words, the expert's cheap talk prevents a voting procedure from aggregating decision makers' private information. We also discuss how our main results extend to a model of Bayesian persuasion