Sheldon is a practicing sociologist and has been active in research on human trafficking and transnational human smuggling activities for more than two decades. Prior to his relocation to the East Coast, Sheldon was also active in research and evaluation on various correctional intervention programs, ranging from juvenile boot camps to intensive probation supervision to wrap-around community reentry programs for justice-involved individuals in California.

He has extensive expertise in planning varied evaluation strategies specific to target populations or contextualized problems, and designing and conducting large scale social surveys. Currently Sheldon spends much of his time evaluating and devising strategies to improve prevalence estimation, survey design, sampling methodologies, and measurement development on human trafficking related topics. He has gained much national and international prominence in designing and conducting large-scale survey projects to estimate the prevalence of human trafficking/forced labor in the U.S. and overseas, including Brazil, Costa Rica, Ghana, India, Kenya, Morocco, South Africa, Thailand, Tunisia, Tanzania, and Vietnam.

Sheldon’s projects have been funded by government agencies and private foundations in the U.S. and abroad. He has written and lectured extensively on topics ranging from human trafficking to migrant smuggling and organized crime. He has been twice invited to the White House to participate in national gatherings of policymakers, advocacy groups, and researchers on combatting human trafficking.  He is a member of the organizing committee for a National Academy of Sciences forum on the latest methodologies for estimating the prevalence of modern slavery. He has authored and co-authored 14 books and edited volumes and more than 150 scholarly journal articles, book chapters, and technical reports.