Inventories, Markups, and Real Rigidities in Menu Cost Models Staff Working Paper 2009-6 Oleksiy Kryvtsov, Virgiliu Midrigan 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 directly related to that of inventories, data on which is readily available. Content Type(s): Staff research, Staff working papers Topic(s): Business fluctuations and cycles, Monetary policy transmission JEL Code(s): E, E3, E31, F, F1, F12