Research and analysis

Modern Slavery: an application of multiple systems estimation

This paper reports on an exploratory analysis of the scale of modern slavery in the UK, using the statistical technique of multiple systems estimation.



This analysis has been conducted by the Home Office Chief Scientific Adviser, Professor Bernard Silverman, to establish a better understanding of the scale of modern slavery in the UK.

The analysis builds on the 2013 NCA Strategic Assessment, which collates data from a wide range of sources to identify potential victims of human trafficking, but inevitably its coverage can be only partial.

By analysing the overlaps between cases that come to attention through various sources, a multiple systems estimation approach can be used to estimate the “dark figure” of cases that have not come to attention.

This approach gives an estimate of between 10 thousand and 13 thousand, in total, of potential victims in the UK in 2013. This includes both the cases already known to the Strategic Assessment as well as the “dark figure”.

We have recently published a new modern slavery strategy that sets out our comprehensive cross-government approach to fighting modern slavery

Published 29 November 2014