We study optimal monetary policy during times of global scarcity of tradable goods. The optimal monetary response entails a surge in inflation, which helps rebalance production toward the tradable sector. While the inflation costs are fully borne domestically, however, the gains in terms of higher supply of tradable goods partly spill over to the rest of the world. National central banks may thus fall into a coordination trap and implement an excessively tight monetary policy causing an unnecessarily sharp global contraction.

This paper describes a paradox of global thrift. Consider a world in which interest rates are low and monetary policy is constrained by the zero lower bound. Now imagine that governments implement prudential financial and fiscal policies to stabilize the economy. We show that these policies, while effective from the perspective of individual countries, might backfire if applied on a global scale. In fact, prudential policies generate a rise in the global supply of savings and a drop in global aggregate demand. Weaker global aggregate demand depresses output in countries at the zero lower bound. Due to this effect, noncooperative financial and fiscal policies might lead to a fall in global output and welfare.