Incarceration and mortality in the United States.

The ongoing COVID-19 pandemic has spotlighted the role of America's overcrowded prisons as vectors of ill health, but robust analyses of the degree to which high rates of incarceration impact population-level health outcomes remain scarce. In this paper, we use county-level panel data from 2927 counties across 43 states between 1983 and 2014 and a novel instrumental variable technique to study the causal effect of penal expansion on age-standardised cause-specific and all-cause mortality rates. We find that higher rates of incarceration have substantively large effects on deaths from communicable, maternal, neonatal, and nutritional diseases in the short and medium term, whilst deaths from non-communicable disease and from all causes combined are impacted in the short, medium, and long run. These findings are further corroborated by a between-unit analysis using coarsened exact matching and a simulation-based regression approach to predicting geographically anchored mortality differences.