Markus K. Brunnermeier
Edwards S. Sanford Professor of Economics
Princeton University, 26 Prospect Avenue, Princeton, NJ 08540, USA (email)
Princeton University, 26 Prospect Avenue, Princeton, NJ 08540, USA (email)
This paper proposes a welfare criterion for economies in which agents have heterogeneously distorted beliefs. Instead of taking a stand on whose belief is correct, our criterion asserts an allocation to be belief-neutral inefficient if it is inefficient under any convex combination of agents' beliefs. While this criterion gives an incomplete ranking of social allocations, it can identify negative-sum speculation in a broad range of prominent models with distorted beliefs.