Sequential Deliberation

We present a dynamic model of sequential information acquisition by a heterogeneous committee. At each date agents decide whether to continue deliberation, generating costly information, or stop and take a binding vote yielding a decision. For homogeneous committees, the model is a reinterpretation of the classic Wald (1947) sequential testing of statistical hypotheses. In heterogeneous committees, the resources spent on deliberation depend on the committee’s preference profile and on the rules governing the deliberation and decision-making processes. Three main insights emerge from our analysis and match an array of stylized facts on jury decision making. First, more heterogeneity of preferences, more consensual deliberation rules, or more unanimous decision voting rules, lead to greater duration of deliberation and more accurate decisions. Second, balanced committees unanimously prefer to delegate deliberation power to a moderate chairman rather than be governed by a deliberation rule such as unanimity. Last, voting rules at the decision stage are inconsequential when either information collection is cheap or deliberation rules are consensual.