Responses to Comments

When he invited me to post about crime and punishment, Eugene suggested that I might want to finish up with a response to comments.   That seems like a good idea.  So let me offer two general remarks, and some specific responses:

In general:

A.  I can’t read Eugene’s mind, but I suspect that he invited me to guest-blog (despite our basic disagreements) for the same reason that I regularly follow  this blog and other libertarian and conservative information channels.  The basic lesson of Bayesian analysis is that you can learn only from information that disconfirms some part of your current belief set.  But of course the natural tendency of the mind is to minimize cognitive dissonance by accepting confirming evidence and rejecting disconfirming evidence, and that tendency is emphasized when beliefs get to be badges of group membership.

This is a deeply unhealthy tendency, and it tends to defeat one of the basic evolutionary strategies of homo sapiens, which Karl Popper summed up as “letting our beliefs die in our place.”  Unfortunately, it has been on full display in the comment threads to my posts, which consisted (when the comments related to the posts at all rather than merely ranting about unrelated topics) mostly of vigorous attempts to prove that the thoughts offered in the posts were worthless or wicked, and the poster an ill-intentioned idiot.

Eugene no doubt thought he was doing his readers a favor by offering them some reading that might challenge their precoceptions.  There is little evidence in the comment thread that the VC readership shares that view, but it’s possible to hope that the comments are not a representative sample of reader reaction.

B.  The suggestion that various non-punitive programs might control crime, and that doing so was preferable, ceteris paribus, to controlling crime by inflicting damage on offenders, met with an especially furious response, mostly centered on the phrase “liberal social engineering.”  But the project of putting 1% of the adult population behind bars – an incarceration rate five times as high as any other advanced democracy, and five times as high as the U.S. ever had before 1975 – is itself a massive, massively risky, and expensive  social-engineering project, and no less massive, risky, or expensive for never having been thought through.   It also involves a completely unprecedented expansion of the power of the state over the individual.

If all taxation is theft, then the $200 billion required to support the current policing, adjudication, and corrections systems is just as much “stolen” as the much smaller sums that might be usefully expended on improving parental performance by poor young first-time mothers, removing lead from the environment, or improving classroom discipline.  If people who call themselves fiscal conservatives understood that a sentence of life without parole imposed on an 18-year-old represented a present-value expenditure of $1 million, the enthusiasm for “throwing away the key” might be diminished.  (An execution, including the due process required – but not sufficient – to prevent the execution of the innocent, costs more.)

In my view, crime at current levels is such a social problem that even substantial increase in the $200 billion criminal-justice budget would be justified by even modest decreases in crime.  If we can spend an extra $10 billion a year to have reduced crime and reduced incarceration, so much the better.

Now for the specifics:

1.  Evidence about the capacity of nurse-family partnerships to reduce offending by more than 50% (based on a randomized controlled trial) is here.

2.  Evidence about the impact of lead on crime takes two forms:  individual-level studies, and econometric studies. The results are consistent, and the effect sizes are large. Moreover, the biology is understood: lead, even at low levels, damages cognitive function, and lower-level cognitive functioning reduces deterrability, thus increasing crime. Moreover, lead does specific damage to impulse control.

Therefore, lead causes crime, and removing lead reduces crime.  It does so more cost-effectively than increasing incarceration, and it has side-benefits rather than side-costs.

3. I have no doubt that a minimum legal drinking age of 21 reduces drinking among minors, and that relaxing that rule would increase drinking (and drinking-related problems) in that population. It also generates massive disobedience and the mass acquisition of false ID.   Increased alcohol taxes are effective in reducing drinking, and especially in reducing heavy, problem drinking (since an extra tax of a dime a drink wouldn’t much bother someone who averages a drink a day). The biggest impacts are on heavy drinking by minors, whose incomes tend to be limited.  A combination of relaxing the age restriction and raising the price could reduce heavy drinking while avoiding the criminalization of mass behavior.