From Edward Baptist’s, The Half Has Never Been Told: Slavery and the Making of American Capitalism.
What enslavers used was a system of measurement and negative incentives. Actually, one should avoid such euphimisms. Enslavers used measurement to calibrate torture in order to force cotton pickers to figure out how to increase their own productivity and thus push through the picking bottleneck. The continuous process of innovation thus generated was the ultimate cause of the massive increase in the production of high-quality, cheap cotton; an absolutely necessary increase if the Western world was to burst out of the 10,000 year Malthusian cycle of agriculture. This system confounds our expectations, because, like abolitionists, we want to believe that the free labor system is not only more moral than systems of coercion, but more efficient. Faith in that a priori is very useful. It means we never have to resolve existential contradictions between productivity and freedom. And slave labor surely was wasteful and unproductive. Its captives knew it wasted the days and years and centuries extorted from them. They would never get those days back. Yet those who actually endured those days knew the secret that, over time, drove cotton-picking to continually higher levels of efficiency. (pp. 130-31 [my emphasis])
Now read Jim Downs’s incredibly thoughtful response to Baptist’s central thesis and the controversy surrounding the review of his book at The Economist.