Lead Exposure, Socioeconomic Status, and Cognitive Disparities

Do socioeconomic status and family circumstances mediate the adverse effects of childhood lead poisoning? Or put more precisely, holding early-life lead exposure constant, do individuals from disadvantaged backgrounds exhibit more serious cognitive and behavioral deficits than individuals from more privileged backgrounds? Using a unique data set that links U.S. army recruits to early life circumstances and random lead exposure among the urban population, we show that the answer to both of these questions is yes. Our estimating strategy exploits a non-monotonic relationship between the pH of drinking water and the water’s lead content. Understanding how early-life conditions mitigate or worsen the adverse consequences of environmental insults, particularly those arising from lead, contributes to our understanding of the economics of human capital formation and the continuity of human capital stocks across generations.