"The Cliometrics literature on slave efficiency has generally focused on static questions. We take a decidedly more dynamic approach. Drawing on the records of 142 plantations with 509 crops years, we show that the average daily cotton picking rate increased about four-fold between 1801 and...

"Between 1800 and 1860, the United States became the preeminent world supplier of cotton as output increased sixty-fold. Technological changes, including the introduction of improved cotton varieties, contributed significantly to this growth. Measured output per worker in the cotton sector rose...