Imperfect international risk sharing and exchange rate volatility matter for how monetary policy should optimally be conducted in an open economy through affecting policymakers terms of trade considerations. I study these motives for a classical and long-standing question in international monetary economics: the size of potential gains from international policy coordination. In a relatively standard model I allow for various degrees of risk sharing by considering different assumptions on international financial markets, and a large region for the crucial parameter of the trade elasticity. When incomplete markets give rise to high volatility of international prices and poor risk sharingsuch as in Corsetti, Dedola, and Leduc (2008)gains from policy coordination are an order of magnitude larger than previous studies, working under the assumptions of complete markets, suggest.
