Crime & Leadishment

[marcusmarcusrc]

An interesting paper was brought to my attention today... remember the whole freakonomics thing about linking abortion rates to violent crime reductions 20 years later? Well, apparently, there may be another factor at work in the crime rate decreases of the past 2 decades: lead abatement.

http://www.nber.org/papers/w13097.pdf

Now, I admit that I am probably predisposed to think this is a good paper because it matches my preconceived notions of "EPA good! Pollution bad!" And I haven't really dug into the numbers. If you want the key results, I'd suggest reading the abstract and then skipping all the way to Table 6 on pg. 59 (the panel results data) and Figure 5 (pg. 70).



Violent crime has a positive relationship (p<0.05) to lead levels and per capita beer consumption and (p<0.10) concealed weapons laws. It has a negative relationship (p<0.05) to abortion and (p<0.10) to police presence per capita.

Property crime: positive (p<0.05): unemployment, concealed weapons, beer consumption. negative (p<0.05) abortion, poverty rate.

Murder: positive (p<0.05): unemployment. negative (p<0.05): abortion, police per capita, and (p<0.10) for poverty.

My thoughts:
Lead: There is a clear mechanism for action, and, for violent crime, what look like good statistics. However, I wonder why lead wouldn't have an effect on property crime or murder? (and the relationship for property crime is, if anything, negative).
Abortion: Looks like the freakonomics hypothesis continues to be statistically significant.
Per capita beer consumption: Reminds me of the rationale for the Temperance Movement.
Unemployment: Not surprising.
Police per capita: Not surprising (though one could imagine that higher crime areas would hire more police, which could dampen this correlation)
Poverty: very surprising, but perhaps due to covariation with unemployment? (and this leads to the question of how many of these variables are related to each other, and how well the statistical methodology handles that: given that the author focused on lead, I'm not sure how much to weigh any of the relationships for the other variables)
Concealed weapons: Interesting... I know that there is research on both sides of this argument.

Discuss?

Comments

[remcat.livejournal.com]

Hmmmm maybe lead damage leads to poor inhibition, thus the violent crime? Violent crime seems more like an impulse control thing. I have a hard time imagining lots of people planning to beat someone senseless after mugging them, but an easy time imagining people planning to break in to a house.

Also, isn't it true that most murders are personal? That is to say, the killer is most cases knows the victim and has a personal reason to kill them? I think it follows that stressful lives (unemployment) might trigger off a murder...

[puffy-wuffy.livejournal.com]

I think property crime and murder are usually somewhat premeditated: so its possible that these are 'unleaded' crimes that are dependent on variables like "is there stuff to steal?" and "do I hate that person?" instead of "hit stuff!"