Attempting to measure modern slavery is not for the faint hearted. You're essentially trying to measure something that is hidden, poorly understood and massively under-reported.
Nevertheless, the global slavery index approach is to take an estimate based on the best available information, as Free the Slaves co-founder Kevin Bales outlined in a piece for the network in October.
The index estimates the size of modern slavery country by country, regionally and globally. It estimates that there are 29.8 million people in some form of modern slavery globally, whether this is a forced marriage or enslavement of workers in brick kilns. Estimates depend in large part on information derived from secondary sources, but also draws upon the limited survey data that is currently available, as well as expert assessment.
Having read Neil Howard's recent piece on the trouble with the global slavery index, we firmly agree with him that there are risks of trying to measure the size of the modern slavery problem through reliance on secondary sources. Primary research that seeks to understand not only the scale of the problem but also its nature – such as Howard's research in Benin – is sorely needed.
In publishing the index, we recognise the limitations of our data and methodology. We also encourage researchers like Howard to challenge our numbers and methods and help us make the data as accurate and useful as possible.
We are not here for the moral high ground – we are here to make the research better and the numbers more accurate, so we can better understand the problem and find meaningful solutions. We are working to improve our research methodology, with more ramdom sample surveys, strict quality checking processes for secondary sources and stronger analysis of government responses.
Howard's points about the impact of agricultural subsidies and trade policy will be taken on board by the team. These are positive contributions to a field that desperately needs information about the size and nature of the problem. As we have always said, we will continuously welcome the opportunity to engage with other researchers and experts in the field. We will be transparent with our data and encourage others to do the same.
Executive director of global research, Walk Free Foundation
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