Economics and Crime

I've always had an interest in economics, and one of the current fads in that field -- apparently, an attempt to rid itself of its reputation as "the dismal science" -- is to apply economic formulations to other areas of the social sciences.  Right now, I'm reading a book called The Myth of the Rational Voter, by Bryan Caplan, an economist at George Mason University.  As is widely known, the level of political knowledge among the American public is abysmal:  a majority can't name a single branch of government; nearly half don't know that states have two senators, and three out of four don't know the length of a Senate term.  More than half can't identify their congressman, and forty percent can't identify either of their senators.

Caplan refines and develops the economic theory for this:  a person's desire to become informed on a particular subject hinges on his expectation of a benefit from acquiring that knowledge.  If I carefully research a stock before buying it, I'm likely to be rewarded by making money.  (Hasn't happened yet, but that's what all the books say.)  What's my reward for carefully researching presidential candidates, though, especially given that there's no chance of my vote making a difference in who wins the election?  I could have spent hundreds of hours in 2004 deciding whether to vote for George Bush or John Kerry, and it wouldn't have made any difference:  George Bush still would have won, regardless of how I voted.  Since there's no penalty for my being politically ignorant (and no reward for being politically knowledgeable), it's more rational to invest my time in other pursuits.

If there's such a thing as a rational voter, then it makes sense to study the idea of the rational killer, too.  Despite widespread acceptance of the belief that capital punishment has no deterrent effect, several recent studies have concluded the contrary.  One, by Naci Mocan, a professor of economics at the University of Colorado, found that each execution prevented five homicides; other studies have produced results claiming that each execution saves as many as eighteen lives.

To be sure, the validity of the new studies is still hotly disputed:  links to the studies can be found here, and links to critiques of them can be found here.  If there is some validity to the them, however, it throws a monkey wrench into the moral debate on capital punishment.  That argument has so far centered on whether the death penalty is morally acceptable.  As some people, including University of Chicago Law Professor Cass Sunstein, an opponent of capital punishment, have pointed out, if the death penalty does in fact deter homicides, it might be morally required

And, of course, economic studies have ventured into the broader area of explanations for crime in general.  A few years back, the authors of Freakonomics advanced the view that the decline of crime in the 80's and 90's was the result of the legalization of abortion.  Now Doug Berman's Sentencing Law & Policy blog points us to a news story about another theory -- the decline was due to the government attempts to eliminate lead poisoning: 

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.

It's not quite as goofy as it sounds, although admittedly it does sound goofy.  Just to be on the safe side, I've decided to modify my client questionnaire for criminal cases.  Question 42 now reads,

As a child, I preferred to eat (circle one):  potato chips        paint chips

I'll let you know what I find out.  Hell, I might even use the results to write a paper in an economics journal.

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