PEI Faculty Seminar Series Video: Lead Exposure and the Black-White Test Score Gap

Igor Heifetz ・ High Meadows Environmental Institute

We consider a new source of racial disparities in test scores: African American students’ disproportionate exposure to environmental toxins, and, in particular, lead. Using a unique individual-level dataset of children’s preschool lead levels linked with future educational outcomes for children in Rhode Island, we document significant declines in racial disparities in child lead levels since 1997, due in part to state policies aimed at reducing lead hazards in homes. Exploiting the change in child lead levels as a result of the policy, we generate causal estimates of the impact of preschool lead levels on reading and math test scores through grade eight in an IV framework. We find that a 5 ug/dl increase in child lead levels (the threshold at which the CDC recommends intervention) reduces test scores by 6 points or 43 percent of a standard deviation. The effects are stronger in the lower tail of the test score distribution and do not appear to fade over time. We calculate that the decline in racial disparities in lead explains roughly half of the decline in racial disparities in test scores witnessed over the past decade in RI.

Janet Currie, Henry Putnam Professor of Economics and Public Affairs, Woodrow Wilson School. Chair, Department of Economics. Director, Center for Health and Wellbeing