The economics of cotton harvest mechanization in the United States, 1920--1970.

摘要

The hallmark of economic development is the long run transfer of labor from agriculture to the industrial and service sectors. This dissertation investigates the mechanization of the cotton harvest, one of the most dramatic episodes of technological change in United States history. Millions of workers from California to the Carolinas handpicked all American cotton in 1945 but by 1970 the crop was harvested by machine.;In order to evaluate the pattern and cause of cotton harvester diffusion I created a time series data set of the ratio of the machine-to-hand cost of harvesting a pound of cotton lint for 12 major cotton-producing states from 1949 to 1964. These data correlate well with the pattern of harvest mechanization and indicate that both failing capital costs and rising hand costs drove diffusion (not just cheaper machines as had been thought).;While sharecroppers and tenants picked southern cotton, I establish that a combination of day-haul laborers, migrants, and foreign workers did so from Texas to California (not just migrants as has been claimed). Western reliance upon spot labor markets allowed adoption of profitable labor-saving devices. Southerners were prevented from using spot labor markets by the combination of high heat and high humidity that deteriorated cotton value. To avoid such losses plantation owners employed a year-around workforce and housed them adjacent to the fields so they could be mobilized during the limited harvest hours available. Growers in the semi-arid west faced a much less complicated cotton harvest problem. This weather-based explanation also accounts for the spatial distribution of plantations within the south and especially the concentration of plantations in the Yazoo-Mississippi Delta.;Finally, I document and quantify the role of the Bracero Program that allowed Mexican laborers to work temporarily in the United States, primarily in cotton fields. During the 1950s braceros comprised 17 percent of the national cotton harvest labor force.;Currently farmers mechanically harvest only 20 percent of the world's cotton. This study of the patterns and consequences of cotton harvest mechanization provides insight for policy makers in countries where this type of future technological change will elicit enormous rural-to-urban migration and capital-for-labor substitution.