A new paper in the American Economic Journal: Economic Policy by Bisschop, Kastoryano, and van der Klaauw looks at the opening and closing of prostitution zones (tippelzones) in 25 Dutch cities.

Our empirical results show that opening a tippelzone reduces sexual abuse and rape. These results are mainly driven by a 30–40 percent reduction in the first two years after opening the tippelzone. For tippelzones with a licensing system, we additionally find long-term decreases in sexual assaults and a 25 percent decrease in drug-related crime, which persists in the medium to long run.

Cunningham and Shah studied decriminalization of indoor prostitution in Rhode Island and found very similar results.

We exploit the fact that a Rhode Island District Court judge unexpectedly decriminalized indoor prostitution in 2003 to provide the first causal estimates of the impact of decriminalization on the composition of the sex market, rape offenses, and sexually transmitted infection outcomes. Not surprisingly, we find that decriminalization increased the size of the indoor market. However, we also find that decriminalization caused both forcible rape offenses and gonorrhea incidence to decline for the overall population. Our synthetic control model finds 824 fewer reported rape offenses (31 percent decrease) and 1,035 fewer cases of female gonorrhea (39 percent decrease) from 2004 to 2009.

read the rest here.