Changes in Mechanical and Plant Technology: The Corn Belt, 1910–1940
研究了1910–1940年间美国玉米带三项重要技术变革（拖拉机替代马匹、杂交玉米种子推广、机械摘穗剥皮机发展）的背景、现有假设及采用带来的每亩成本节约或额外收入，并指出关于玉米改良研究的经济理性及“干井效应”的假设可能需要修正。
During the period 1910–1940 some changes were occurring in the production practices of the Corn Belt. Three of the most important were the substitution of the tractor for horse power, the introduction of hybrid seed corn, and the development of viable mechanical picker-huskers for harvesting corn. This paper examines the background of those innovations, evaluates current assumptions about them, presents data concerning the relative per acre savings or additional income involved in adoption, and notes the possibility that assumptions about the economic rationality involved in corn improvement research, as well as the implications of the “dry hole effect,” may require some revision.