The underground economy around prostitution thriving in most communities is extremely difficult to quantify.
Sex workers and their clients rarely generate receipts. (The fact that they sometimes do is a story for another time.) Pimps pulling in thousands of dollars in cash in a typical week rarely pay no taxes on that income. (Yeah, another time.) And now that the market lives and thrives on the Internet rather than the street, it has become more laborious for law enforcement to determine financial transactions within the paid-sex industry.
These are just some of the reasons whey we have no reliable data on human trafficking.
In fact, since John D. Rockefeller published "Commercialized Prostitution in New York City," over 100 years ago, there has been no solid data on exactly how large the underground commercial sex economy is, especially within individual cities . . . . until now.
Recently, the Urban Institute published an exhaustive inquiry into the subject in eight U.S. cities, in a report funded by the research arm of the Department of Justice. Broadly, the study concludes that local illegal sex markets are extensive, lucrative and perhaps more sophisticated than you think – and that the Internet has transformed them.
Read the important article at http://www.examiner.com/article/after-100-years-the-truth-about-human-trafficking