Deliberation, disclosure of information, and voting

A set of voters consults a set of experts before voting over two alternatives. Agents have private biases over which alternative they prefer ex ante, but may be swayed by information about relative values of the alternatives. Experts observe private signals about the relative values of the alternatives and can choose to either reveal that information or conceal it, but they cannot lie. We examine how disclosure and voting behaviors vary with the intensity and heterogeneity of the preference biases, the informativeness of signals, and the structure of the voting rule. The voting rule that maximizes information disclosure can be a supermajority rule favoring one of the two alternatives, and in some cases unanimity rule can dominate simple majority rule both in terms of information revelation and total utility maximization, even in a fully symmetric society. The voting rule that maximizes information disclosure need not coincide with the voting rule that maximizes total utility. We also show that in a large enough society, full information revelation is approximated via any voting rule, and with sufficient symmetry simple majority rule is approximately ex ante efficient.