Environmental Policy as Social Policy? The Impact of Childhood Lead Exposure on Crime

Abstract

Childhood lead exposure can lead to psychological traits that are strongly associated with aggressive and criminal behavior. In the late 1970s in the United States, lead was removed from gasoline under the Clean Air Act. I use the state-specific reductions in lead exposure that resulted from this removal to identify the effect of childhood lead exposure on crime rates. The elasticity of violent crime with respect to childhood lead exposure is estimated to be 0.8, and this result is robust to numerous sensitivity tests. Mixed evidence supports an effect of lead exposure on murder rates, and little evidence indicates an effect of lead on property crime. Overall, I find that the reduction in childhood lead exposure in the late 1970s and early 1980s was responsible for significant declines in violent crime in the 1990s and may cause further declines in the future. Moreover, the social value of the reductions in violent crime far exceeds the cost of the removal of lead from gasoline.

Lead Exposure and Behavior: Effects on Antisocial and Risky Behavior Among Children and Adolescents

“…Second, social scientists struggle to explain trends in mental health and social behaviors, including learning disabilities, adolescent violence, teen 58. Reyes (2007). pregnancy, and substance abuse.…”

“…Ethyl Corporation (1976-1984, National Institute for Petroleum Energy Research and BETC (). The measurement of gasoline lead is discussed at length in Reyes (2007).…”

“…Sources: Gibbs (1990Gibbs ( , 1993Gibbs ( , 1996 and Gibbs personal communication. 45. See Reyes (2007) for a detailed discussion of the merits of different ways of measuring lead. question.…”

Lead exposure and child maltreatment as models for how to conceptualize early‐in‐life risk factors for violence

“…A second piece of evidence that lead has causal effects on aggression comes from quasi-experimental studies. Using national data, Reyes (2007) showed that violent crime rates dropped by 56% from the early to the late 1990s, a decade during which the population of young adults shifted from those whose childhoods predated the passage of the Clean Air Act (1963) to those who benefited from reductions in airborne lead produced by this legislation. Moreover, states that showed the largest declines in leaded gasoline levels also showed the largest reductions in crime (Reyes, 2007).…”

Introduction to special issue on quasi-causal methods

“…Take, for example, a 2007 retrospective study that used variation in adoption of lead reduction policies across U.S. states to establish a causal connection between childhood lead exposure and subsequent state crime levels (Wolpaw Reyes 2007). Clearly, this study capitalized and relied on variations in policy implementation that were outside of the researcher's control.…”