Goldin and Katz (1998) examine the origins of technology-skill and capital-skill complementarity in manufacturing from 1909 to 1929. They find that these complementarities were associated with continuous-process and batch methods and the adoption of electric motors. Industries using more capital and electricity employed more educated blue-collar workers and paid them more. Capital-skill complementarity is also evident in the wage-bill for non-production workers. The authors link these findings to the high-school movement (1910–1940), suggesting that the increased supply of skilled labor may have reduced inequality with technological change. They argue that technology-skill and capital-skill complementarity emerged as batch and continuous-process methods spread and electrification became widespread. The shift from artisanal shops to factories increased capital-output ratios and decreased the demand for skilled labor, but the shift to continuous-process methods increased the relative demand for skilled labor. The adoption of electric motors and unit-drive machines further reinforced this trend. The authors also find that the relative demand for skilled labor increased in industries using more electricity and capital. They conclude that the 1910s were a critical period for the development of capital-skill complementarity in American industry, as new goods and processes were introduced, often requiring more skilled labor. The findings suggest that capital-skill complementarity has been a persistent feature of the labor market, with the effects becoming more pronounced in recent decades.Goldin and Katz (1998) examine the origins of technology-skill and capital-skill complementarity in manufacturing from 1909 to 1929. They find that these complementarities were associated with continuous-process and batch methods and the adoption of electric motors. Industries using more capital and electricity employed more educated blue-collar workers and paid them more. Capital-skill complementarity is also evident in the wage-bill for non-production workers. The authors link these findings to the high-school movement (1910–1940), suggesting that the increased supply of skilled labor may have reduced inequality with technological change. They argue that technology-skill and capital-skill complementarity emerged as batch and continuous-process methods spread and electrification became widespread. The shift from artisanal shops to factories increased capital-output ratios and decreased the demand for skilled labor, but the shift to continuous-process methods increased the relative demand for skilled labor. The adoption of electric motors and unit-drive machines further reinforced this trend. The authors also find that the relative demand for skilled labor increased in industries using more electricity and capital. They conclude that the 1910s were a critical period for the development of capital-skill complementarity in American industry, as new goods and processes were introduced, often requiring more skilled labor. The findings suggest that capital-skill complementarity has been a persistent feature of the labor market, with the effects becoming more pronounced in recent decades.