Collective Deliberation Under Non-common Prior: Theory and Experimentation

Abstract

The well-known jury paradox - the more demanding the hurdle for conviction is, the more likely it is that a jury will convict an innocent defendant - heavily relies on Bayesian Updating. However, with ambiguous information (e.g., a forensic test with accuracy of 60%, or more), Bayesian updating becomes invalid, challenging the existence of this paradox. To advance our understanding of collective decision-making, we study deliberations under ambiguity both theoretically and experimentally, informing the institutional design of collective deliberation, for small to large group decision-making.