Inflation equals the product of two terms: an extensive margin (the fraction of items with price changes) and an intensive margin (the average size of those price changes). The variance of inflation over time can be decomposed into contributions from each margin. The extensive margin figures...

Real rigidities that limit the responsiveness of real marginal cost to output are a key ingredient of sticky price models necessary to account for the dynamics of output and inflation. We argue here, in the spirit of Bils and Kahn (2000), that the behavior of marginal cost over the cycle is...