Empirically, sales are I(1). Starting from this fact, we derive three startling results. First, the variance of production is equal to the variance of sales in the long run. Second, this result holds regardless of the strength of production smoothing, stockout avoidance, or cost shocks. Third,...

Economic theory predicts a negative relationship between inventories and the real interest rate, but previous empirical studies (mostly based on the older stock adjustment model) have found little evidence of such a relationship. We derive parametric tests for the role of the interest rate in...

This paper presents a model that provides an explanation, based on regime switching in the real interest rate and learning, of why tests based on stock adjustment models, Euler equations, or decision rules—which emphasize short-run fluctuations in inventories and the interest rate—are...

Empirically, ADF tests fail to reject the null hypothesis that sales are I(1). We build a model of inventory behavior that incorporates permanent sales shocks. Analytically, the model with I(1) sales implies that the variance ratio (of log production to log sales) is one in the long run,...

We derive parametric tests for the role of the interest rate in specifications based on the firm's optimization problem. These Euler equation and decision rule tests mirror earlier evidence, finding little role for the interest rate. We present a simple and intuitively appealing explanation,...