Over the past decade, global concern about human trafficking has prompted massive investment into anti-trafficking interventions by intergovernmental organizations, states and civil society. While early interventions took place in a performance evaluation vacuum, there have been growing calls for greater transparency and accountability within the anti-trafficking sector, including through rigorous impact evaluation. Such calls are fully justified. The human rights imperatives that underpin anti- trafficking work and the significant investment of public resources demand that interventions demonstrate accountability, results and beneficial impact. However, in practice this is more complicated and there has been relatively little analysis of the practical issues and challenges that arise in efforts to evaluate anti-trafficking work. In the specialized area of criminal justice responses to trafficking, such analysis is virtually non-existent, despite the increasing attention and resources that are being directed to this aspect of the anti-trafficking response. Impact and effectiveness evaluation in the context of international development is both complicated and contested. Multiple theories and elaborate methodologies abound, and these can present a daunting impediment to those seeking practical guidance on the essential problem of determining “what works”. This paper seeks to cut through some of the complexities by focusing attention on several areas that are directly implicated in measuring anti-trafficking interventions in the criminal justice sector. It is the result of a comprehensive review of relevant literature and recent evaluation reports as well as interviews with key players in the field.
