Estimating the trafficked population: Public health research methodologies may be the answer

Authors: Fedina, Lisa & DeForge, Bruce

Abstract: Inevitably, there are a great number of methodological challenges and limitations to estimating the extent of human trafficking, which are largely due to definitional issues and the hidden nature of the trafficked population. To date, most national and global estimates of the problem have been discredited for using flawed, nontransparent, or nonexistent research methods; however, researchers have previously suggested that methodologies from public health, including those used to estimate hidden and transient populations, might also be useful to estimate the trafficked population. Specifically, research design, sampling strategies, and measures commonly used to estimate hidden populations in public-health research may hold promise for future human-trafficking studies, reducing bias and resulting in more narrow and precise range estimates of victims. This article presents examples of studies using public-health research methods to estimate various hidden and stigmatized populations (e.g., injection drug-users, homeless and runaway youth) and proposes a set of strategies that might be considered for future prevalence studies on human trafficking. Recent prevalence studies on human trafficking that have successfully implemented public-health research methods, such as Respondent-Driven Sampling and Venue-Based Sampling, are also discussed.

Keywords: estimates, measurement, methodology, prevalence, sampling