Voting to persuade

We consider a model of collective persuasion, in which members of an advisory committee with private continuous signals vote on a policy change. A decision maker then decides whether to adopt the change upon observing each vote. Information transmission between the committee and the decision maker is possible if and only if there exists an informative equilibrium in which the decision maker only adopts the policy change after a unanimous vote. Similarly, full information aggregation is achievable if and only if such an equilibrium exists when the size of the committee is large enough. We further discuss why our continuous-signal model produces results different from discrete-signal models.