I don’t think any other group is as loathed by society as sex offenders–and rightfully so. But how to punish them? Sex offender registries? Are they actually effective at reducing crime? Do they actually increase the risk of crime (putting aside any issues of blame–the offender, and not the registry commits the crime). From Marginal Revolutions:
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.