When my colleagues and I received a National Institute of Justice grant in 2010 to undertake a major scientific study of the underground commercial sex economy, I knew it would be challenging, in part due to the diversity of people involved in the sex trade, the complexity of their experiences, and the public debates on the legality/illegality of the commercial sex trade. Since we released our 350-page report last Wednesday, the response has been commensurately large and, in some cases, heated.

I appreciate the feedback we’ve received about some of the questions our report does and does not address, as well as about how we employed specific methods and chose the terminology used throughout the report. Below, I clarify some critical points about our study.

Sex trafficking and sex work are not synonymous. There is indeed an inherent danger in conflating sex trafficking with sex work. They are not the same, and understanding the distinction is important. We were very aware of this distinction when conducting this study and were careful when deciding what terminology to use. We define our terminology in chapters 1 and 2, including what we mean by “pimp,” “sex work,” “sex trafficking,” and “underground.”

• Pimp: someone who facilitates prostitution and profits in some way from doing so. Pimping often—but not always—involves fraud, coercion, or force.
• Sex work: a term used to refer to all types of lawful and unlawful commercial sex activity. Critically, a sex worker can engage in sex work both legally and illegally, and voluntarily or through force, fraud, or coercion.
• Sex trafficking: the use of force, fraud, or coercion to engage another person in sex work, with the exception of minors where force, fraud, and coercion does not need to be present (their status as a minor automatically classifies them as a trafficking victim according to federal law).
• Underground: any type of sex work that is illegal. Stripping, dancing, and adult pornography are legal (above ground) sex work activities.

Throughout our report, we take special care to define and use these terms appropriately. Our report’s goal is to fill key knowledge gaps related to the underground commercial sex economy.

We attempt to fill a major gap in understanding the underground commercial sex trade. Some expressed concern that, because we interviewed more pimps, we didn’t fairly or adequately address the perspective of sex workers themselves. While we dedicate an entire chapter (chapter 8) to the perspective of sex workers (we interviewed 36 sex workers, compared with 73 pimps), there are two primary reasons for dedicating several chapters to the pimps’ perspective.

First, while quality research and advocacy work has documented the sex trade from sex workers’ perspectives, comparatively little is known about the size of the sex trade, how it operates from a business perspective, and how its networks intersect from the perspectives of pimps and others who facilitate the trade. Thus, one of the main goals of our study was to bridge that critical gap in understanding.

Second, gathering data from both pimps and sex workers allowed us to develop the first scientifically rigorous estimates of the size of the underground commercial sex economy. As with all social science research, there were limitations to our methodology, but we’ve created a model that others can expand, refine, and improve. It’s the first time such a scientific model has existed for this underground but real aspect of our economy.

In empirical research, limitations do not imply bias. One reason there is so little understanding—especially rigorous empirical understanding—of the underground commercial sex economy is that it is, by definition, underground. It is quite difficult to find and speak openly with the people involved.

But, in our extensive documentation, we list the limitations of our sample, as well as our attempts to include as many perspectives as possible. Indeed, we spoke with men, women, trans-women, pimps, sex workers, law enforcement, and other key stakeholders.

What’s more, we developed a rigorous empirical methodology (described in chapter 3); analyzed a number of different official, public data sets; and used qualitative and quantitative methods to triangulate our findings as thoroughly as possible.

Though our estimates are just that—estimates—they are scientific and rigorous. As resources and data availability permit, our innovative model can be expanded and improved to provide clearer and more precise figures.

Lastly, no matter where you fall in the debate on this issue, we encourage you to read the report and engage with others in an informed and civil discussion.