New Keynesian theory identifies a set of principles central to the design and implementation of monetary policy. These principles rely on the ability of a central bank to manage expectations precisely, with policy prescriptions typically derived under the assumption of perfect information and...

We study zero interest-rate policy in response to a large negative demand shock when long-run expectations can fall over time. Because falling expectations make monetary policy less effective by raising real interest rates, the optimal forward guidance policy makes large front-loaded promises to...

This paper develops a theory of expectations-driven business cycles based on learning. Agents have incomplete knowledge about how market prices are determined and shifts in expectations of future prices affect dynamics. In a real business cycle model, the theoretical framework amplifies and...

Survey data on expectations of a range of macroeconomic variables exhibit low-frequency drift. In a New Keynesian model consistent with these empirical properties, optimal policy in general delivers a positive inflation rate in the long run. Two special cases deliver classic outcomes under...