Microeconomic Inventory Behavior and Aggregate Inventory Dynamics

Abstract

The slow adjustment of inventory stocks to changes in sales has been a puzzle for the inventory literature since at least Auerbach and Feldstein (1976). Recent evidence suggests that estimated firm-level adjustment speeds of inventory stocks are significantly higher than estimates based on aggregate data. This paper investigates the circumstances under which such bias occurs using an industry equilibrium model where, consistently with empirical evidence, some firms smooth production while others bunch it. The model can account for the significant downward bias documented empirically when a subset of firms displays countercyclical mark-up movements.