Information aggregation and communication in committees

In this paper, we attempt to explain the underlying strategic incentives confronting individuals when they must make a collective decision over a set of alternatives and each has information that is decision-relevant for others. A significant literature has emerged in formal political theory over the past several years that focuses on such problems, paying particular attention, first, to the extent to which voting can be expected to aggregate committee members' information and, second, to the role of communication among committee members prior to voting. Inter alia, this literature reveals a surprisingly subtle interaction between the voting rules used to make decisions and the incentives for committee members to share information prior to voting

Deliberation, Preference Uncertainty and Voting Rules

A deliberative committee is a group of at least two individuals who first debate about what alternative to choose prior to these same individuals voting to determine the choice. We argue, first, that uncertainty about individuals’ private preferences is necessary for full information sharing and, second, demonstrate in a very general setting that the condition under which unanimity can support full information revelation in debate amounts to it being common knowledge that all committee members invariably share identical preferences over the alternatives. It follows that if ever there exists an equilibrium with fully revealing debate under unanimity rule, there exists an equilibrium with fully revealing debate under any voting rule. Moreover, the converse is not true of majority rule if there is uncertainty about individuals’ preferences