Human trafficking

Human trafficking

Human trafficking

The crime of human trafficking is complex and dynamic, taking place in a wide variety of contexts and difficult to detect. One of the greatest challenges in developing targeted counter-trafficking responses and measuring their impact is the lack of reliable, high-quality data related to the scale of human trafficking and the profile of victims.

The need for improved international response to human trafficking and commitment to its eradication is illustrated by its prominent inclusion in the targets of the United Nations (UN) Sustainable Development Goals (SDGs) and the Global Compact for Safe, Orderly, and Regular Migration (GCM). Eradicating human trafficking is addressed specifically in goals 5.2, 8.7 and 16.2. The GCM’s 10th Objective also calls for specific measures to prevent and combat trafficking in persons in the context of international migration.


The Protocol to Prevent, Suppress and Punish Trafficking in Persons defines human trafficking or trafficking in persons:

“Trafficking in Persons”… mean[s] the recruitment, transportation, transfer, harbouring or receipt of persons, by means of the threat or use of force or other forms of coercion, of abduction, of fraud, of deception, of the abuse of power or of a position of vulnerability or of the giving or receiving of payments or benefits to achieve the consent of a person having control over another person, for the purpose of exploitation. Exploitation shall include, at a minimum, the exploitation of the prostitution of others or other forms of sexual exploitation, forced labour or services, slavery or practices similar to slavery, servitude or the removal of organs. (Article 3, paragraph (a)).

The Protocol further elaborates that the consent of a trafficked person may be rendered irrelevant when obtained through improper means:

The consent of a victim of trafficking in persons to the intended exploitation set forth in subparagraph (a) of this article shall be irrelevant where any of the means set forth in subparagraph (a) have been used; (Article 3, paragraph (b)).

In the case of trafficked children, the Protocol elaborates that the vulnerable status of children makes it impossible for them to consent regardless of whether any improper means were used or not:

The recruitment, transportation, transfer, harbouring or receipt of a child for the purpose of exploitation shall be considered “trafficking in persons” even if this does not involve any of the means set forth in subparagraph (a) of this article; (Article 3, paragraph (c)).
“Child” shall mean any person under eighteen. (Article 3, paragraph (d)).

Recent trends

Since the early 2000s, the proportion of identified cases of trafficking for sexual exploitation has in general declined, while the share of identified cases of trafficking for forced labour has generally increased, as identification of such cases has improved. However, there are regional differences in the rates of both trafficking for sexual exploitation and forced labour. For example, data from UNODC and CTDC show that trafficking for forced labour has a higher rate in Africa and the Middle East than trafficking for sexual exploitation, while the opposite is true for regions such as Europe and Northern America.1 This is partly reflected in the CTDC data above, where an increase of available case data from Northern America from 2015 onwards increased the proportion of victims trafficked for sexual exploitation in the dataset.   


A large proportion of victims identified are female, as human trafficking had previously tended to be seen as a crime which affects mostly females who are trafficked for sexual exploitation. Over time, a higher percentage of men have been identified as it has been acknowledged that men can also be vulnerable to many forms of human trafficking, including sexual exploitation, and the identification of such cases has improved. The proportion of children relative to adults for males and females is about the same.

CTDC data also show differences in the routes undertaken by victims of trafficking. Nearly 80 per cent of international human trafficking journeys cross through official border control points, such as airports and land border control points. Victims of labour exploitation are more likely to be trafficked through official border control points, while victims of trafficking for sexual exploitation account for more cases crossing borders via locations that don’t have official border control points. This includes irregular routes, such as those across the sea or cross-country. Children are also more likely than adults to be trafficked via routes that don’t have official border control points.


Half of the victims identified by CTDC partners are under 26. Nearly a quarter of them are children. In fact, the largest age group in the whole distribution is 15 to 17 years old.

Data sources

The main sources of data on human trafficking globally are based on information provided by identified victims. These are usually collected by a range of different actors, including law enforcement, the judiciary, and non-governmental organizations providing protection and assistance to victims.

Several UN agencies and international non-governmental organizations (NGOs) have collaborated to produce data sources on the profiles of victims of human trafficking, the prevalence of human trafficking, and on related phenomena such as forced labour and forced marriage.
Operational case data and victim profiles

In the course of protecting and providing services to victims, counter-trafficking actors frequently collect individual-level, operational case data. IOM has been providing direct assistance to victims of human trafficking since the mid-1990s and assists approximately 8,000 victims each year globally. Through its case management activities, the Organization has developed the largest database of victim of trafficking case data in the world, with information on over 55,000 individual cases.

Operational data from counter-trafficking organizations are often highly sensitive and pertain to individuals, which raises a range of privacy and civil liberty concerns where the risk of identifying data subjects can be high and the consequences severe. While many organizations and governments around the world collect data on cases of human trafficking, disaggregated data has not been easily accessible to external stakeholders or has not been frequently shared between relevant actors in the past due to the sensitivity of its content, and data protection and confidentiality considerations.

To overcome these challenges, in 2017, IOM made its own data publicly available online through the Counter Trafficking Data Collaborative (CTDC), along with combined data from other leading counter-trafficking organizations with significant case-level datasets.

The Counter Trafficking Data Collaborative

The Counter Trafficking Data Collaborative (CTDC) is the first global data hub on human trafficking, with data contributed by organizations from around the world. The resulting dataset is the largest of its kind globally, with information on over 108,000 individual cases of human trafficking visualized throughout the site, including through an interactive global map. An anonymized version of this dataset is publicly available to download. By putting such data in the public domain, the goal of CTDC is to break down information-sharing barriers and equip the counter-trafficking community with up to date, reliable data on human trafficking. As new data from contributing partners are added, CTDC will continue to expand in scope, featuring new datasets from diverse counter-trafficking actors and disseminating standards on sharing trafficking-case data.

IOM’s Counter Trafficking Data Collaborative has made great progress in overcoming data obstacles, but more work is needed throughout the counter-trafficking community to agree on common standards and methods of data sharing and applicability. Disaggregated case-level data are the most detailed source of information on human trafficking and should thus play a vital part of any meaningful analysis on the phenomenon.

National reporting mechanisms

Another key source of trafficking information is official reports on administrative data compiled by governments (or other central reporting bodies) on human trafficking cases within their national jurisdictions.

UNODC surveys governments on trafficking victims identified in their respective countries for the Global Report on Trafficking in Persons, using a common questionnaire with a standard set of indicators, and then aggregates the results.  The most recent global report was produced in 2018. In 2016, this exercise produced data on more than 24,000 identified victims of trafficking from 97 governments, a peak compared to the previous years. Data are largely published in the form of total numbers disaggregated by variables such as sex, age, and type of exploitation, wherever possible. In addition to government surveys, UNODC collects official information such as police reports that are available in the public domain, and some information from inter-governmental organisations and NGOs.

Estimating prevalence of human trafficking

There are currently no global or regional estimates of the prevalence of human trafficking.

Some national estimates have been developed, including using human trafficking administrative data:

Multiple Systems Estimation is the methodology used to estimate the total (unidentified and identified) victims of trafficking at country level. This is based on the analysis of the overlap of multiple lists of human trafficking cases provided by different actors in the counter-trafficking field, such as NGOs, law enforcement, other authorities and international organizations. MSE depends upon the existence of various databases of identified victims of human trafficking in the country of implementation. A number of other technical assumptions should also be met. For example, it must be possible for more than one entity recording administrative data to be able to independently identify a victim of trafficking. Researchers developing the method have estimated that it could potentially be used in approximately 50 countries around the world. Initial estimates have already been conducted in several countries, including the UK and the Netherlands.

Relatively few examples of estimates of related forms of exploitation exist:

  • 2017 Global Estimates of Modern Slavery – This is a global estimate of the prevalence of the human-trafficking-related crimes of forced labour and forced marriage, produced by the International Labour Organisation (ILO) and the Walk Free Foundation (WFF), in collaboration with IOM. The 2017 report estimates that 40 million people were victims of modern slavery in any given day in 2016. Out of these, approximately 25 million people were in forced labour and another 15 million people were in a forced marriage. Data from IOM’s human trafficking database on sexual exploitation and child exploitation were used for the estimates.
  • Estimating forced labour, forced recruitment and abductions in displacement contexts. IOM is developing a series of comparable estimates on prevalence of forced labour, forced marriage, forced recruitment into armed groups and abductions among Internally Displaced People (IDPs) and their families, in partnership with ILO and WFF. This is a pilot research initiative in three countries with large numbers of IDPs and where IOM has substantial humanitarian operations and suitable sampling frames. The report with the findings, methodology and recommendations will be published in 2020.


Trafficking in humanitarian settings and large-scale migration flows

Humanitarian crises such as those associated with conflicts or natural disasters may exacerbate pre-existing trafficking trends and give rise to new ones. While some forms of trafficking could be a direct result of crises, such as exploitative sexual services demanded by armed groups or the forced recruitment of child soldiers, others are less evident, with traffickers thriving on the widespread human, material, social and economic losses caused by crises and the inability of families and communities to protect themselves and their children.

IOM works to combat trafficking and protect trafficked persons in humanitarian settings. To address the acute need for data for evidence-based programming in these location, IOM has been using its Displacement Tracking Matrix to regularly collect data on risks and issues relevant to human trafficking and exploitation in crises. In addition, IOM with partners is also working to produce prevalence estimates on issues related to human trafficking.

Locations of recent regular data collection with human trafficking indicators include Cox’s Bazar in Bangladesh, North-East Nigeria, Ukraine, Central and South American countries. The data gathered during these operations can be used to better understand risks to trafficking, vulnerability to exploitation, gaps in assistance and to identify areas of further research.

IOM, through DTM, also produces primary data on the migrants’ vulnerability to human trafficking, abuse, exploitation and violence on different migration routes, for example on the main migration routes to Europe. Data with trafficking indicators are collected in countries like Italy, Libya, or Greece. Further similar data collection is planned in countries from Central and West Africa, and in Eastern Africa.

IOM produced a report with UNICEF on the specific experiences of children and youth migrating via the Mediterranean migration routes to Europe. In a separate report, IOM identified predictors of vulnerability to human trafficking and exploitation for migrants taking these routes. There is limited reliable data on human trafficking and exploitation in displacement contexts.

Data strengths & limitations

Operational case data and victim profiles

The availability of data on identified victims of trafficking depends on a range of factors, for example on whether counter trafficking organizations are operational or able to consistently collect or share data in any given country/location. Therefore, data coverage is not always comprehensive. Presence of large quantities of human trafficking data may not necessarily indicate higher prevalence, and a paucity of data in certain contexts may be due a lack of effective counter-trafficking responses.  Identified cases are better understood as a sample of the unidentified population of victims. This sample may be biased if some types of trafficking cases are more likely to be identified (or referred) than others. Even if this is the case, the extent of the bias is rarely known, since the unidentified population is, by definition, unknown. Nevertheless, where available, these data are indispensable, as they provide detailed insight into the profiles and experiences of the victims, the forms of human trafficking, and information on perpetrators.

National reporting mechanisms

While data from National Reporting Mechanisms are not detailed and generally only available as high-level aggregates, limiting their use, they have the widest geographical coverage and therefore provide useful baseline information on human trafficking at the global level. Furthermore, in the absence of publicly available disaggregated data, official reports may be the only source of data on identified victims available in a given country or region.

Estimating prevalence of human trafficking

National estimates of trafficking prevalence have been produced in several countries. However, they are commonly based on modelling of existing administrative data from identified cases and should therefore only be considered as basic baseline estimates. Historically, producing estimates of the prevalence of trafficking based on the collection of new primary data, for example through surveys, has been difficult. This is due to trafficking’s complicated legal definition and the ethical challenges of addressing sensitive questions to household survey respondents. Not all countries can be sampled due to resource constraints, security reasons, or the presence of large-scale humanitarian emergencies. There are also ethical considerations and further challenges related to large-scale household surveys in terms of the sensitivity of certain questions (for example, questions related to sexual exploitation or violence) and the difficulty of collecting data about children. This makes the case data mentioned above all the more valuable, both to gain insights on these specific profiles and to support estimations.

Trafficking in humanitarian settings and large-scale migration flows

Finally, humanitarian settings are often highly pressurised and fast changing environments, where conducting rigorous and ethical data collection can be challenging. For example, access to affected populations for data collectors can rapidly change, and services relevant for assistance of victims of human trafficking might not initially exist in crisis-affected locations.  Therefore, the methods of data collection need to avoid causing harm, and they need to be time-sensitive and adaptable. Sampling best practices can also be challenging to implement in some environments.

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