For the past twenty years much forward movement in the field of anti-trafficking
and anti-slavery has been blocked by conflicts over definitions, and the lack of a
shared approach to measuring the scale of the problem.
The findings and recommendations in this report bring the perspective and participation of contemporary
survivors of trafficking and slavery to bear on these issues of definition and measurement. The idea of
defining a criminal act which does not include the perspective of victims of that crime seems inadequate.
We believe that active survivor participation improves the quality and depth of the research and its
There are two dimensions to the
Modern Slavery: Meaning and Measurement
project reflected in this
report. First, through the collecting of first-hand contemporary survivor narratives, and an analysis of
how formerly enslaved people who became antislavery leaders during past abolitionist movements
understood and used definitions of slavery, the findings bring new depth and integrity to legal,
operational and popular definitions.
Second, the findings address the measurement of modern slavery, re-testing the application of Multiple
Systems Estimation (MSE) techniques to the hidden population of slavery and trafficking victims and
exploring ways in which its uptake and use can be promulgated to inform better policy-making and
Kevin Bales CMG, Prof. of Contemporary Slavery and Research Director at The Rights Lab, University of
Modern slavery, and its conduit activity human trafficking, are well known as enterprises in which trans-
national organised crime is active. Yet, the response, in law, policy, and voluntary action, to this crime is
confounded by two fundamental challenges: 1. an inability to achieve a clear and agreed definition of
the crime itself (especially across national jurisdictions); and 2. an inability to achieve valid and reliable
measurement of its incidence.