Suchergebnisse

Childhood lead exposure can lead to psychological deficits 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. Using the sharp state-specific reductions in lead exposure resulting from this removal, this article finds that the reduction in childhood lead exposure in the late 1970s and early 1980s is responsible for significant declines in violent crime in the 1990s, and may cause further declines into the future. The elasticity of violent crime with respect to lead is estimated to be approximately 0.8.

In many academic settings, undergraduate economics majors are asked to do an independent project or thesis in their final year. Because doing research is very different from learning economics in a classroom, students are frequently unprepared for this endeavor. This article describes a seminar course intended to ease this transition by preparing students to embark on such a project. The first goal of the course is to assist students in developing a sound economic research project. The second goal is to help them develop the research skills to execute their project. In essence, the course is an abbreviated and accelerated version of some of the learning that takes place alongside the standard curriculum in graduate school. The article describes a course that has been designed for a liberal arts setting, and also discusses other possible variations.

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.