Dan Black is a labor economist at the University of Chicago Harris School of Public Policy and NORC. He works on labor market dynamics, poverty, and disability program participation. He is best known in the DI literature for Black, Daniel, and Sanders (2002), which uses the coal boom and bust in Appalachian states as a natural experiment to provide the first clean causal evidence that permanent labor market conditions — not transitory earnings fluctuations — drive DI and SSI participation. The paper's OLS≈0 / IV strong result resolved a longstanding puzzle about near-zero income elasticities of disability program take-up.