Sex offender registries contain a disturbing amount of information about sex offenders. The Washington DC, registry, for example, provides photos of sex offenders and will map their homes and workplaces down to the block level. The CA registry includes photos and maps unique home addresses. In some states, neighbors are notified by telephone when a registered sex offender moves into the neighborhood.

Sex offenders are often also highly restricted on where they can work and live–so much so, that in some states they have been effectively banished. In CA, sex offenders must be monitored via GPS for life. Many states allow sex offenders to be kept in prison past their sentences, based only on a judge’s opinion that the sex offender might commit a future crime. Bear in mind that teenagers having sex with other teenagers, hiring or trying to hire a prostitute and even streaking can make a person fall under the sex offender statutes. Moreover, contrary to popular belief, sex offenders have low recidivism rates, much lower than for most other crimes.

Why the obsessive focus on sex crimes? I see it as coming from deep and primitive feelings and fears about sex, after all we don’t have homicide registries. At least not yet. Sex offender registries, however, may be the thin end of the wedge. How long will it be before we require monitoring of all convicted criminals? Will we soon wear augmented reality spectacles that list the criminal history of individuals as they pass by on the street (and perhaps also their credit ranking?). Is this really a good idea? At the very least, it’s important to know whether these laws deter crime and if so whether they are cost effective. Two new papers in the Journal of Law and Economics examine these issues.

J.J. Prescott and Jonah Rockoff find that registries can have a modest deterrent effect on crime but that notification laws can increase recidivism. Notification laws and other such punishments can increase recidivism because they make it much harder for registered offenders to find a job and reintegrate into society.

I especially like Amanda Agan’s paper Sex Offender Registries: Fear without Function?. Agan writes:

I find little evidence to support the effectiveness of sex offender registries, either in practice or in potential. Rates of sex offense do not decline after the introduction of a registry or public access to a registry via the Internet, nor do sex offenders appear to recidivate less when released into states with registries. The data from Washington, D.C., indicate that census blocks with more offenders do not experience statistically significantly higher rates of sexual abuse, which implies that there is little information one can infer from knowing that a sex offender lives on one’s block.

Agan’s paper is unusual in that it uses three different datasets and a variety of empirical strategies. It also makes clever use of geocoded crime data and the aforementioned sex offender home and work addresses from the DC registry.

Full Disclosure: Agan’s paper was written, under my direction, when she was an undergraduate at George Mason University. Amanda is now nearing her graduation from the PhD economics program at the University of Chicago.