I saw this via Kevin Drum about a week ago and meant to put a post up because it is both stunning and fascinating. Mark Kleiman has a book out on criminal justice and punishment by the name of When Brute Force Fails. The reviews have been fantastic, but it is the discussion of the effects of reduction in lead exposure on the crime rate that caught my eye:
Given the decrease in lead exposure among children since the 1980s and the estimated effects of lead on crime, reduced lead exposure could easily explain a very large proportion — certainly more than half — of the crime decrease of the 1994-2004 period. A careful statistical study relating local changes in lead exposure to local crime rates estimates the fraction of the crime decline due to lead reduction as greater than 90%.
Jeebus; that is pretty eye opening. Granted, there are a lot of nits that could be picked as to whether this is a direct or correlative relationship and, even if it is direct, to what extent it is so; however, it is a hell of a discussion point.
A 2007 Washington Post article described one of the studies behind Kleiman’s assertion:
The theory offered by the economist, Rick Nevin, is that lead poisoning accounts for much of the variation in violent crime in the United States. It offers a unifying new neurochemical theory for fluctuations in the crime rate, and it is based on studies linking children’s exposure to lead with violent behavior later in their lives.
What makes Nevin’s work persuasive is that he has shown an identical, decades-long association between lead poisoning and crime rates in nine countries.
“It is stunning how strong the association is,” Nevin said in an interview. “Sixty-five to ninety percent or more of the substantial variation in violent crime in all these countries was explained by lead.”
Through much of the 20th century, lead in U.S. paint and gasoline fumes poisoned toddlers as they put contaminated hands in their mouths. The consequences on crime, Nevin found, occurred when poisoning victims became adolescents. Nevin does not say that lead is the only factor behind crime, but he says it is the biggest factor.
As an added bonus, the Post article uses Nevin’s study to mock Rudy Giuliani’s constant claim that he is Read more