Estimating the extent of Modern Slavery

This report provides a brief critical review of the ways in which national and global estimates of the extent of modern slavery have been calculated and offers a new model which can be used to calculate both regional and national estimates. One of the objectives in developing the model was to use a parsimonious method, which was based on direct indicators of victimisation. Additionally, rather than using statistical inferences to compute unknown figures, proportional estimates were garnered from empirical research on other forms of interpersonal crime that have commonalities with modern day slavery. In this report the model is used to provide an estimate of the extent of modern slavery in the Thames Valley region. Two estimates are produced here. One which over time will enable assessment of the criminal justice response to modern slavery and the other which will be beneficial in terms of service and resource planning for organisations working with victims. To overcome the difficulties in producing estimates a potential survey instrument is offered to capture primary data.