What may have Pb to the drop in violent crime?

This is a very compelling story in Mother Jones by Kevin Drum about how the leaded gasoline that was used in automobiles from the late 1930's until the early 1970's may very well have contributed to a large amount of violent crime over decades here in the USA and around the world.  The data is striking.  It appears that Freakonomics was wrong on the subject of why there was such a widespread drop in violent crimes starting around 1990.  read the whole thing..

    Mother Jones:  America's Real Criminal Element: Lead

"... But as Nevin was working on that assignment, his client suggested they might be missing something. A recent study had suggested a link between childhood lead exposure and juvenile delinquency later on. Maybe reducing lead exposure had an effect on violent crime too?

That tip took Nevin in a different direction. The biggest source of lead in the postwar era, it turns out, wasn't paint. It was leaded gasoline. And if you chart the rise and fall of atmospheric lead caused by the rise and fall of leaded gasoline consumption, you get a pretty simple upside-down U: Lead emissions from tailpipes rose steadily from the early '40s through the early '70s, nearly quadrupling over that period. Then, as unleaded gasoline began to replace leaded gasoline, emissions plummeted.

U pattern. The only thing different was the time period: Crime rates rose dramatically in the '60s through the '80s, and then began dropping steadily starting in the early '90s. The two curves looked eerily identical, but were offset by about 20 years.

    


After making the connection between lead exposure and violent crime, Drum questions why is it that no one who studies or works in the business of fighting crime seems to be interested.

Nevin calls it "exasperating" that crime researchers haven't seriously engaged with lead, and Reyes told me that although the public health community was interested in her paper, criminologists have largely been AWOL. When I asked Sammy Zahran about the reaction to his paper with Howard Mielke on correlations between lead and crime at the city level, he just sighed. "I don't think criminologists have even read it," he said. ..

Why not? Mark Kleiman, a public policy professor at the University of California-Los Angeles who has studied promising methods of controlling crime, suggests that because criminologists are basically sociologists, they look for sociological explanations, not medical ones. My own sense is that interest groups probably play a crucial role: Political conservatives want to blame the social upheaval of the '60s for the rise in crime that followed. Police unions have reasons for crediting its decline to an increase in the number of cops. Prison guards like the idea that increased incarceration is the answer. Drug warriors want the story to be about drug policy. If the actual answer turns out to be lead poisoning, they all lose a big pillar of support for their pet issue. And while lead abatement could be big business for contractors and builders, for some reason their trade groups have never taken it seriously.

He goes on to point out that for roughly $20 billion per year for 20 years we could all but eliminate much of the lead that remains in windows in old houses and soil in mostly urban areas and how getting the lead out  would generate ten times that much in savings from the lower crime levels and higher IQ levels that would result.

That is how you invest in the future of a nation. Not by producing, selling and squirreling away firearms and precious metals.  Invest in the children by getting rid of the lead left from the past that shackles them for life.