Should juries deliberate?

Abstract

What form should jury decision-making take? In particular, should juries be permitted—even encouraged or required—to make their decisions by means of free, unstructured deliberation? In this paper, I argue that juries should not engage in such deliberations on the way to reaching a verdict. In particular, I argue that jury deliberation is problematic on both theoretical and empirical grounds. On the theoretical front, deliberation destroys the independence of jurors’ judgments that is needed for certain theoretical results (in particular, the Condorcet Jury Theorem) to be applicable. On the empirical front, there is evidence from both legal and non-legal contexts that unstructured group deliberation leads to group judgments that are worse in a number of respects than judgments generated by non-deliberative methods of judgment aggregation. Finally, I examine some possible alternatives to unstructured deliberation, including the constrained, structured deliberation embodied in the DELPHI method, voting (without deliberation), and averaging of probabilistic judgments