There is increasing pressure in international development to demonstrate that aid spending has an impact. This includes spending on policy research. While there is much debate about appropriate methods and evidence for demonstrating impact, ‘a more recent development is the movement to include practice-based evidence alongside more traditional scientific evidence in the accumulation of knowledge about what works, when, and why?’ (Forss, Marra and Schwartz 2011: 5).
The concept of practice-based evidence accepts that the world is a complicated, messy place that cannot be easily controlled. Those promoting its use suggest that it can provide additional insight about impact. Impact evaluation is an assessment of both the intended and unintended outcomes of a given intervention, where ‘the proper analysis of impact requires a counterfactual of what those outcomes would have been in the absence of the intervention’ (OECD 2001).
This paper explores the challenge of using practice-based evidence gathered with civil society organisations – and agencies that support them – to learn more about the impact of policy-related work. Specifically, it uses the work undertaken in the Sexuality, Poverty and Law programme at the Institute of Development Studies, and focuses on one case study that looked at sex workers’ experiences of economic empowerment programmes in Ethiopia. The purpose is not to assess the case study or particular interventions, but to better understand what policy impact might look like.