Optimal economic institutions under rational overconfidence,with applications to the choice of exchange rate regime

We study the optimal choice of exchange rate regime when agents have beliefs that are mutually inconsistent. A general framework for identifying optimal policies in such situations is proposed and then used to compare fixed and floating exchange rate regimes. Agents are assumed to have diverse rational beliefs (rather than rational expectations), implying the prevalence of (rational) overconfidence. We argue that in such a situation, in comparing economic institutions, one should employ the concept of ex‐post optimality rather than that of Pareto optimality. Fixing the exchange rate is ex‐post optimal because it eliminates mistaken actions (based on mistaken beliefs).