From Plantations to Prisons: The Legacy of Slavery on Black Incarceration in the US.

Black males constitute 6.5% of the US population but account for 40% of the prison population. The extent to which these disparities reflect differences in criminal conduct and socio-economic background, as opposed to differential treatment is a long-standing question. However, little is known about the roots of this disparity. This paper uses US decennial censuses for the period 1850 to 1940 to show that the race gap in incarceration can be traced back to the abolition of slavery in 1865. In particular, I exploit the variation in the prevalence of slavery across counties in southern states to estimate the short- and long-run impact of slavery on black incarceration rates.   I document a substantial increase in black incarceration immediately after the abolition of slavery, with no comparable effect on whites, and that this black-white incarceration gap continued to grow. These baseline OLS results are not driven by omitted variables given their robustness to: (i) observable controls, which proxy for racial attitudes and socioeconomic and geographic characteristics, (ii) analyses of neighboring counties that are more likely to be comparable on unobservable dimensions, and (iii) an IV analysis that instruments for slavery intensity with cotton suitability.

Using novel historical data on prison work camps from the Department of Labor, I provide evidence that the high levels of black incarceration in the US started, at least in part, due to labor scarcity in which convict labor was used to replace slave labor.  This mechanism is further supported in analyses of three natural experiments — land grant allocations, Boll Weevil cotton pests, and the Mississippi River floods — that reduced the demand for labor; these reverse shocks are associated with lower black incarceration rates.