ILO's New Estimate of the Number of Slaves Worldwide: 20.9 Million

Posted by Stephen M. Bauer June 13, 2012

ILO's New Estimate of the Number of Slaves Worldwide: 20.9 Million

On June 1, the United Nations’ International Labor Organization (ILO) published a revised estimate of the number of slaves worldwide--20.9 million. Accurate data on slavery is essential for developing effective institutional policies for its eradication. The ILO’s statistics on global slavery are considered the most authoritative estimate. They are used not only by the U.N. but by the U.S. Department of State, as well as most foreign governments and anti-trafficking NGOs.

In 2005, the ILO had published the results of their initial attempt to estimate the number slaves in the world--12.5 million. Having revised the number upward in 2012, the ILO cautions to not conclude that the total has increased. The 2005 figure was considered only an estimate of the minimum number of slaves. The 2012 study was based on a more sophisticated methodology, plus more and better data sources. The new total is not considered a minimum estimate, but it is still considered a conservative estimate.

The report breaks down the number of slaves according to various categories: geographic region, age, gender, form of slavery--sexual or labor, and how many were enslaved while migrating for work or otherwise crossing borders. The study shows that Asia and the Pacific region have the largest number of slaves—11.7 million. More males than females are enslaved in labor slavery, but both women and children are much more vulnerable to sexual slavery. Fifty-five percent of female slaves are used in sex slavery. Twenty-six percent of all slaves are children. Ninety-eight percent of sex slaves are female. Half of all enslavements lasted for 6 months or less, with an average enslavement of 18 months.

Migration has been a well known risk factor for human trafficking, but estimates based on movement were not included in the 2005 study. The 2012 study shows that of slaves who crossed borders, 74% are used for sexual exploitation. Bear in mind that slaves who have crossed borders may have been enslaved first, and then forced to cross a border, or they may have crossed a border voluntarily and been enslaved afterwards.

The study was conducted using a statistical sampling methodology called capture-recapture. This is a technique that was developed for estimating counts of elusive populations—like the number of fish in a pond or the number of homeless people in a city. It involves taking two different samples from a population, measuring the overlap between the two samples, applying some mathematics and extrapolating.

In this study, the two samples were taken by two different teams that worked independently from each other. The team members were given two days of training and testing in identifying the conditions that constitute slavery. The two teams were given offices in areas that were separate from each other, and they were instructed to not communicate with each other. The raw data that they collected was taken from media reports, NGOs, government bodies including the police, academic reports, ILO reports, and worker unions. Specialists at the ILO verified that each case of enslavement met the ILO definition of slavery. The overall survey was subject to peer review by an independent panel of academic researchers and several government agencies. Among the members of the peer review panel was Nomi Network Advisory Board member Siddharth Kara.

Apparently, few nations attempt to survey or estimate the number of human trafficking victims within their borders. Among the ILO's sources of data on human trafficking victims were ten governments, of which only four had conducted national surveys. While the 2012 ILO study was a great deal more comprehensive than the one in 2005, the ILO is hoping to get more countries to survey human trafficking activity, in order to compile more accurate estimates in the future. Beate Andrees, of Geneva, Switzerland, is the head of the ILO’s Special Action Programme to Combat Forced Labour and was the project manager for the study. In an interview with Al Jazeera, in response to a question about trends in global slavery, she said, “Well, the truth is we don’t really know what the trends are because the data is still very weak. We have seen, as compared to 2005 when we published our first figures, that indeed the number is much higher than we thought back in 2005. And that’s shocking—it’s an urgent call for action. We also see that the Africa region is actually more affected than we thought a few years ago. This is probably due to that we have much better data now from Africa, so we have a better understanding of the problem in this region.”

Let us not forget the human faces behind the statistics. Beate Andrees says, “Most victims don’t dare to denounce their exploiters. They are in a very difficult situation, under threat. Very often the coercion is subtle, but those who are affected don’t know where to turn for help.”

A Summary of the Results

Classification	Category	Number of Slaves, Millions	Percent of Total Slaves	Slaves per 1,000

Total	Worldwide	20.9	100%	3

Migrants	Migrant Workers	9.1	44%
	Non-Migrant Workers	11.8	56%

Form of Slavery	Labor	14.2	68%
	Sexual	4.5	22%
	State Imposed Labor	2.2	10%

Age	Adults	15.4	74%
	Children	5.5	26%

Age, Sex Slaves	Adults	3.555	79%
	Children	0.945	21%

Gender	Female	11.4	55%
	Male	9.5	45%

Sex Slaves	Male	0.09	2%
	Female	4.41	98%

Regions	Asia and Pacific	11.7	56%	3.3
	Africa	3.7	18%	4
	Latin America and Carib,	1.8	9%	3.1
	East/South/Cent Eur.; CIS	1.6	7%	4.2
	Dev'd Nations includ. EU	1.5	7%	1.5
	Middle East	0.6	3%	3.4

A Summary of the Results by Migration Status

Category	Percent Cross Border	Percent Internal Migration	Percent None
Sex Slaves in Private Economy	74.0	19.0	7.0
Labor Slaves in Private Economy	18.5	15.2	66.3
State Imposed Forced Labor	0.0	6.0	94.0
Total	29.0	15.0	56.0