http://www.forbes.com/sites/alexknap...rime-epidemic/

How Lead Caused America's Violent Crime Epidemic

All of it points to one simple idea: violent crime rose as a result of lead poisoning because of leaded gasoline. It declined because of lead abatement policies.

There are three basic reasons why this theory should be believed.
Identified in the article

This quote is relevant to the Effects Based Operations crowd and their faith in measuring observables:

In particular, it’s important because this is precisely the kind of problem that people are uncomfortable about believing. It’s hard for us to see the link between cause and effect when there’s a 20+ year gap between one and the other. Additionally, none of us like thinking that our autonomy as human beings can be destroyed by forces beyond our control that we can’t even see.

But such time lags between cause and effect do exist.
Lot of interesting links at the article below. The article that kicked this off was in Mother Earth News

http://www.motherjones.com/kevin-dru...crime-linkfest

Lead and Crime: A Linkfest

Baselines vs. crime waves. Lots of things contribute to baseline levels of crime. But lead is uniquely able to explain why there was such a huge rise of crime above the baseline during the 60s, 70s, and 80s, followed by an equally huge reduction back to the baseline in the 90s and aughts.

Big cities vs. small cities. Surprisingly, it turns out that once you reduce exposure to gasoline lead, big cities aren't really all that much more dangerous than small ones after all
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