Demand uncertainty is thought to in uence irreversible capacity decisions. Suppose local demand can be sourced from domestic (rigid) production or from (fl exible) imports. This paper shows that the optimal domestic capacity is either increasing or decreasing with demand uncertainty depending on the relative level of the costs of domestic production and imports. This relationship is tested with data on the U.S. cement industry, where, because cement is costly to transport over land, the diff erence in marginal cost between domestic production and imports varies across local U.S. markets. Industry data for 1999 to 2010 are consistent with the predictions of the model. The introduction of two technologies to the production set one rigid and one exible is crucial in understanding the relationship between capacity choice and uncertainty in this industry because there is no relationship at the aggregated U.S. data. The analysis presented in the paper reveals that the relationship is negative for coastal districts, and signi cantly more positive in landlocked districts.
