Persuasion and Information Aggregation in Elections

This paper studies a large majority election with voters who have heterogeneous, private preferences and exogenous private signals. We show that a Bayesian persuader can implement any state-contingent outcome in some equilibrium by providing additional information. In this setting, without the persuader's information, a version of the Condorcet Jury Theorem holds. Persuasion does not require detailed knowledge of the voters' private information and preferences: the same additional information is effective across environments. The results require almost no commitment power by the persuader. Finally, the persuasion mechanism is effective also in small committees with as few as 15 members.