Comparative Judgement Modeling to Map Forced Marriage at Local Levels

Forcing someone into a marriage against their will is a human rights violation. In 2021, the county of Nottinghamshire, UK, launched a strategy to tackle forced marriage and violence against women and girls. However, there is no high resolution spatial information of where victims are located in the county, so it is not possible to develop targeted interventions to support victims. Comparative judgement studies are being used to measure human rights abuses, but are currently limited to applications where no local level application is needed and there are a large number of judges. We develop a new comparative judgement model that provides a more flexible spatial modelling structure and a mechanism to schedule comparisons more effectively. The methods reduce the data collection burden on individual participants and make a comparative judgement study feasible with a small number of participants. Underpinning these methods is a P\'olya-Gamma latent variable representation that improves on the scalability and efficiency of previous comparative judgement models. We map the risk of forced marriage across Nottinghamshire and support the county's strategy for tackling violence against women and girls.