Collaborative Research: The Differential Impact of Parasitic Diseases on Agricultural Productivity of Blacks and Whites in the Early Twentieth-Century South

该项目研究了寄生虫病对20世纪初美国南部不同祖先遗产人口生产力的影响。 这项研究具有历史意义，因为它量化了地方性寄生虫病与两个历史上重要的人口，非洲裔美国人（黑人）和欧洲裔美国人（白人）的经济福祉之间的关系。 该项目有助于解释美国南部的经济发展，并解决有关19世纪南方奴隶制生产力的问题。 研究的重点是疾病的地理特征以及黑人和白人对特定地方病，主要是寄生钩虫和疟疾的不同生物易感性。 该研究收集了洛克菲勒档案中心关于20世纪初南方11个州所有可用县寄生虫病流行情况的档案数据。 该项目利用现有的疾病流行率和各种气候、地理、病因学因素以及其他疾病相关数据，估计（估算）缺乏明确疾病数据的南部各县的疾病流行率。 这项研究采用了明确的和插补的疾病患病率沿着与农业投入和产出的数据，为968个南部县，估计在县级经济生产力（农业产出）之间的差异黑人和白色农业劳动力。 生产力的计量经济学估计控制了其他相关变量，并纠正了各种统计问题。该项目更广泛的意义在于，它为估计寄生虫病在当今世界的影响提供了数据。 地方性钩虫和疟疾在解释20世纪早期南方黑人和白色农业劳动力的经济生产力方面的作用有助于理解这些疾病对今天经济的影响。 钩虫目前感染了世界人口的20%至33%;疟疾感染了3亿至5亿人，每年造成200万至300万人死亡。 这些疾病的经济影响并不十分精确，但20世纪初的估计表明，钩虫使劳动生产率从20%降低到70%。 疟疾的经济影响目前正在研究之中。 对钩虫影响的一个假设但似乎合理的估计说明了这些疾病可能造成的巨大损失。 使用20%的钩虫感染率意味着全世界约有12亿人感染。 如果钩虫感染了人均收入相当于800美元的人。S.钩虫每年造成的经济损失高达1440亿美元（世界上最贫穷国家的人口），年生产率仅下降15%。 以4%的利率计算，这意味着世界上最贫困人口的财富将永久减少3.6万亿美元。 这种计算是不精确的。 但它表明，在大多数发展中国家，控制地方性寄生虫病可能是消除贫困的有效途径。 该项目对钩虫和疟疾造成的经济生产力损失的估计为估计这些疾病的同期影响确立了更精确的界限。

This project examines the impact of parasitic diseases on the productivity of populations of different ancestral heritages in the early 20th-century American South. The research has historical significance because it quantifies the relationship between endemic parasitic diseases and the economic well-being of two historically important populations, African-Americans (blacks) and European-Americans (whites). The project helps explain the economic development of the American South and address questions concerning the productivity of 19th-century southern slavery. The research focuses on the geographical distinctiveness of diseases and the differential biological susceptibilities of blacks and whites to particular endemic diseases, primarily to parasitic hookworm and malaria. The research gathers archival data from the Rockefeller Archive Center on the prevalence of parasitic diseases in the early 20th-century for all available counties for eleven southern states. The project uses the available disease prevalence rates with various climatic, geographical, etiological factors, and other disease-related data to estimate (impute) disease prevalence rates for those southern counties that lack explicit disease data. The research employs the explicit and imputed disease prevalence rates along with agricultural input and output data for 968 southern counties to estimate differences in county-level economic productivity (agricultural output) between black and white agricultural labor. The econometric estimations of productivity control for other pertinent variables and correct for various statistical concerns.The broader significance of the project is that it provides data for estimating the impact of parasitic diseases in the world today. The role of endemic hookworm and malaria in explaining early 20th-century economic productivity of southern black and white agricultural labor assists in understanding the economic impact of these diseases today. Hookworm currently infects between 20 and 33 percent of the world's population; malaria infects 300 to 500 million people and kills 2 to 3 million per year. The economic impact of these diseases is not known with much precision, but early 20th-century estimates suggest hookworm reduced labor productivity from 20 to 70 percent. Malaria's economic impact is just now being studied. A hypothetical but plausible estimate for the impact of hookworm alone illustrates the possible magnitude of the costs of these diseases. Using the 20 percent hookworm infection rate means that about 1.2 billion people worldwide are infected. If hookworm infects people with a per capita income equivalent of $800 U. S. dollars (people in the world's poorest nations) and reduces annual productivity just 15 percent, the economic losses due to hookworm alone are $144 billion per year. Capitalized at an interest rate of 4 percent, this represents a permanent wealth reduction of $3.6 trillion for the world's poorest peoples. This calculation is imprecise. But it suggests that throughout much of the developing world the control of endemic parasitic diseases may be an effective way to combat poverty. This project's estimation of the lost economic productivity attributable to hookworm and malaria establishes more precise boundaries for estimating the contemporaneous effects of these diseases.