Local Evidence and Diversity in Minipublics

A policymaker selects a minipublic—a group of citizens from a demographically diverse citizenry with access to local evidence about the impact of a policy. Citizens face uncertainty about the policymaker’s eventual policy bias, which is shown to discourage the most marginally informative minipublic citizens from discovering their evidence. We fully characterize the optimal minipublic composition. Relative to the most demographically representative minipublic, the optimal minipublic overrepresents demographics at the margins of the citizenry while underrepresenting those around the median citizen. The representativeness of the optimal minipublic varies nonmonotonically with uncertainty. Our findings bear practical implications for minipublic design.