The link between output changes and factor-mix adjustments in general equilibrium is examined for each of nine industries using pooled data from 12 developed countries over the years 1970-85. Specifications of the Stolper-Samuelson theorem and the specific-factors model of production are built on the assumptions and structure of theory with each industry isolated in turn. In their simplest version with only capital and labor input, these competitive general-equilibrium models explain a good deal of the observed variations in industrial factor mixes. The specific-factors model performs better. Copyright 1997 by Blackwell Publishing Ltd.