The Phillips curve has been much flatter in the past twenty years than in the preceding decades. We consider two hypotheses. One is that prices at the microeconomic level are stickier than they used to be---in the context of the canonical Calvo model, firms are adjusting prices less often. The...

New Keynesian models with sticky prices and rational expectations have a difficult time explaining why reducing inflation usually requires a recession. An explanation for the costliness of reducing inflation is that inflation expectations are less than perfectly rational. To explore this...