RESOLUTE AND CORRELATED BAYESIANS

This paper suggests a new normative approach for combining beliefs. We call it the evidence-first method. Instead of aggregating credences alone, as the prevailing approaches, we focus instead on eliciting a group’s full probability distribution on the basis of the evidence available to its members. This is an altogether different way of combining beliefs. The method has four main benefits: (1) it captures the weight, or resilience, of a group’s belief; (2) it is sensitive to correlation among its individuals; (3) it is commutative under updating; and (4) it can be seen as a generalization of weighted averaging and likelihood ratio approaches. More broadly, it encourages an overall rethinking of the belief combination problem away from aggregating bare credences and toward appropriately combining evidence.

Duke Scholars

Author Robert L. Winkler Fuqua School of Business