Measuring Human Trafficking
The challenges in estimating human trafficking are similar to those of estimating forced labour.
At the global level, UNODC’s Global Report “provides an overview of patterns and flows of trafficking in persons at global, regional and national levels, based primarily on trafficking cases detected between 2012 and 2014.”
“As for any crime, there is an unknown “‘dark figure'” of criminal activity that is never officially detected. As such, the figures … do not and cannot reflect the real extent of the crime of trafficking in persons, but rather, a sub-population of victims and offenders that can be used to infer some information on patterns and flows of this crime.”
“The quantitative and qualitative information that form the basis of the Global Report was collected by UNODC in two ways: through a dedicated questionnaire distributed to governments and by the collection of official information available in the public domain (national police reports, Ministry of Justice reports, national trafficking in persons reports, etc.). Countries that are not covered by the data collection did not respond to the questionnaire, and UNODC was also not able to locate official national data on trafficking in persons.”
“The analysis presented in the Global Report draws upon data on detected victims and cases which mostly reflect the ability of local authorities to detect and report trafficking cases rather than the full extent of the crime. Conclusions … should be read with this limitation in mind.”
Estimating Human Trafficking: MSE
Multiple Systems Estimation (MSE) is an innovative statistical approach to estimate the size of hidden populations. Adapted from a method widely used in the biological science, known as “capture-recapture” method, MSE uses the overlap in lists of victims to estimate the size of the victim population. It has been used in the UK (by the UK Home Office), the Netherlands (UNODC) and is now being applied in other countries, to estimate the number of victims of modern slavery and human trafficking. These new estimates suggest that earlier estimates were too low.
Data Collection: Government Victim Assistance
As data collection becomes an increasingly common practice in the public sector, more and more data are available from diverse government entities. One way data collection and consolidation have been scaled up to add to what we know about human trafficking prevalence is through establishing National Referral Mechanisms.
A National Referral Mechanism (NRM) is a cooperative framework through which state actors fulfil their obligations to protect and promote the human rights of trafficked persons, coordinating their efforts in a strategic partnership with civil society. Recently, NRMs have served as essential sources of information for governments to collect data necessary to estimate the total number individuals victimized by human trafficking.
Data Collection: International and Non-Governmental Organizations
Civil society organizations (CSOs) focused on human trafficking victim assistance can serve as crucial sources of data through their ability to reach a population that is notoriously difficult to sample.
Liberty Asia: Organizations like Liberty Asia have helped NGOs that assist survivors by establishing systems to collect and store victim data that can be used to tell a story about which types of industries are doing the exploiting and where individuals are being trafficked from, among other things.
IOM Counter Trafficking Data Collaborative (CTDC): The International Organization for Migration (IOM), Polaris and Liberty Asia have launched a global data repository on human trafficking, with data contributed by counter-trafficking partner organizations around the world.
Not only does the CTDC serve as a central repository for this critical information, it also publishes normed and harmonized data from various organizations using a unified schema. This global dataset facilitates an unparalleled level of cross-border, trans-agency analysis and provides the counter-trafficking movement with a deeper understanding of this complex issue. Equipped with this information, decision makers will be empowered to create more targeted and effective intervention strategies.
Data Collection: Prosecution Data
UNODC compiles a global dataset on detected and prosecuted traffickers, which serves as the basis in their Global Report for country profiles. This information is beginning to paint a picture of trends over time, and case-specific information can assist investigators and prosecutors.