As with most drugs, I'm on the side of regulation. And this is the case in my country (Uruguay), where sex workers are now largely organized and can pay taxes and retire just like any other job. (pimps are illegal)
I find the idea of reducing human trafficking through full criminalization to be questionable from the point of view of personal freedoms (voluntary choice) and its results, with the biggest problem being the consequences for all sex workers themselves, the alleged victims from this point of view. These people can't freely ask the police for help when mistreated, can't apply for any social benefit, have to suffer through social discrimination in general, and can end up in jail. Prostitution won't disappear any time soon no matter how much you criminalize it, and an illegal sex worker will always be far more exposed to exploitation, diseases and violence than a legal one. The activity and the people involved can be better monitored and treated when they're on the side of the law.
Corruption will exist either way, so I don't think that's an argument against regulation. Any cultural or economic element that may incentivize it can be fought in its own ground, besides all this.
PS: In case someone is interested and hasn't seen it yet, here's Penn and Teller's Bullshit! episode on the matter. (NSFW)
