This paper examines the effect of skill-biased technological change as measured by computerization on the recent widening of U. S. educational wage differentials. An analysis of aggregate changes in the relative supplies and wages of workers by education from 1940 to 1996 indicates strong and persistent growth in relative demand favoring college graduates. Rapid skill upgrading within detailed industries accounts for most of the growth in the relative demand for college workers, particularly since 1970. Analyses of four data sets indicate that the rate of skill upgrading has been greater in more computer-intensive industries.

Current concern with the impact of new technologies on the wage structure motivates this study. We offer evidence that technology-skill and capital-skill (relative) complementarities existed in manufacturing early in this century and were related to the adoption of electric motors and particular production methods. Industries, from 1909 to 1929, with more capital per worker and a greater proportion of motive energy coming from purchased electricity employed relatively more educated blue-collar workers in 1940 and paid their production workers substantially more. We also find a strong positive association between changes in capital intensity and the nonproduction worker wage bill from 1909–1919 implying capital-skill complementarity as large as in recent years.