Contrary to popular belief, the linear quadratic inventory model does
not imply that, in response to demand shocks, output is always less va
riable than sales. When demand shocks are not anticipated, and without
this assumption it is hard to see why firms should hold inventories i
n the first place, it is shown that output can be more variable than s
ales, even when the only shocks are demand shocks, and the inventory t
arget is not a rising function of sales. The variance of output will t
ypically exceed that of sales when the firm's marginal cost curve is f
airly flat.