Estimating the Number and Prevalence of Forced Labor Victims Among Domestic Workers in Casablanca, Morocco: A Comparison of Mark-Recapture and Vincent Link-Tracing Sampling Strategies

Author: Cole, Katrina; Sahai, Ridhi; Vincent, Kyle; Rezwan, Mayumi; Iyer, Mithila; Kysia, Kareem; Wang, Xichen & Zhang, Sheldon

Abstract: This study was one of seven projects funded under the Prevalence Reduction Innovation Forum (PRIF) Program at the University of Georgia to advance knowledge on human trafficking prevalence estimation strategies. In this study, we evaluated two strategies for studying hard-to-reach populations – mark-recapture (MR) and Vincent link-tracing sampling (VLTS) – to estimate the prevalence of forced labor among domestic workers within a well-defined geographical area in Casablanca, Morocco. We found the VLTS strategy generally produced higher estimates of trafficking than an MR strategy The VLTS strategy estimated 34.15% (95% CI [0.30, 0.38]) of the target population are potential victims of domestic servitude, while the MR strategy estimated 28.73% (95% CI [0.26, 0.32]) of the population. The implications of these findings for future prevalence estimation are discussed.

Keywords: domestic servitude, forced labor, human trafficking, mark-recapture, prevalence estimationr, espondent-driven sampling