Optimal Macroprudential and Monetary Policy in a Currency Union

I solve for optimal macroprudential and monetary policies for members of a currency union in an open economy model with nominal price rigidities, demand for safe as- sets, and collateral constraints. Monetary policy is conducted by a single central bank, which sets a common interest rate. Macroprudential policy is set at a country level through the choice of reserve requirements. I emphasize two main results. First, with asymmetric countries and sticky prices, the optimal macroprudential policy has a country-specific stabilization role beyond optimal regulation of financial sectors. This result holds even if optimal fiscal transfers are allowed among the union members. Second, there is a role for global coordination of country-specific macroprudential policies. This is true even when countries have no monopoly power over prices of internationally traded goods or assets. These results build the case for coordinated macroprudential policies that go beyond achieving financial stability objectives.