Optimal monetary and fiscal policy in a currency union with frictional goods markets

We develop an open economy model of a currency union with frictional goods markets and endogenous search decisions to study optimal monetary and fiscal policy. Households finance consumption with a common currency and can search for locally produced goods across regions that differ in their market characteristics. Equilibrium is generically inefficient due to regional spillovers from endogenous search decisions. While monetary policy alone cannot correct this distortion, fiscal policy can help improve allocations by taxing or subsidizing production at the regional level. When households of only one region can search, optimal policy entails a deviation from the Friedman rule and a production subsidy (tax) if there is underinvestment (overinvestment) in search decisions. Optimal policy when households from both region search requires the Friedman rule and zero production taxes in both regions.