Inventories and the Business Cycle: An Equilibrium Analysis of (S,S) Policies

37 Pages Posted: 13 Nov 2003 Last revised: 17 Jul 2022

See all articles by Aubhik Khan

Aubhik Khan

Ohio State University (OSU)

Julia K. Thomas

University of Minnesota - Twin Cities - Department of Economics; National Bureau of Economic Research (NBER)

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Date Written: November 2003

Abstract

We develop an equilibrium business cycle model where nonconvex delivery costs lead producers of final goods to follow generalized (S,s) inventory policies with respect to intermediate goods. When calibrated to match the average inventory-to-sales ratio in postwar U.S. data, our model reproduces two-thirds of the cyclical variability of inventory investment. Moreover, inventory accumulation is strongly procyclical, and production is more volatile than sales, as in the data. The comovement between inventory investment and final sales is often interpreted as evidence that inventories amplify aggregate fluctuations. Our model contradicts this view. Despite the positive correlation between sales and inventory investment, we find that inventory accumulation has minimal consequence for the cyclical variability of GDP. In equilibrium, procyclical inventory investment diverts resources from the production of final goods; thus, it dampens cyclical changes in final sales, leaving GDP volatility essentially unaltered. Moreover, although business cycles arise solely from shocks to productivity and markets are perfectly competitive in our model, it nonetheless yields a countercyclical inventory-to-sales ratio.

Suggested Citation

Khan, Aubhik and Thomas, Julia K., Inventories and the Business Cycle: An Equilibrium Analysis of (S,S) Policies (November 2003). NBER Working Paper No. w10078, Available at SSRN: https://ssrn.com/abstract=467546

Aubhik Khan

Ohio State University (OSU) ( email )

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Julia K. Thomas (Contact Author)

University of Minnesota - Twin Cities - Department of Economics ( email )

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