Impact evaluations provide empirical evidence showing whether development interventions result in measurable impact and greater aid effectiveness. Impact evaluations answer the fundamental question: what would have happened to beneficiaries if they had not received the intervention? It assesses the impact that can be attributed to a particular project, program, or policy. Assessing the impact requires comparing the units (e.g., individuals, households, and/or enterprises) that receive an intervention with the counterfactual scenario in which similar units do not receive an intervention.
While there is a large body of empirical work on the effects of economic growth and human capital development on poverty reduction, there is little evidence on the development effectiveness of individual projects and programs. A more systematic measurement of project/program outcomes through impact evaluation supports evidence-based policymaking and helps development partners design and implement further assistance more effectively. ADB recognizes that impact evaluation will help ADB and its developing member countries (DMCs) to assess the consequences of development initiatives and help allocate limited resources more efficiently, guide the design of more effective interventions, and enable evidence-based policy dialogue.
In line with the agenda on managing for development results and to mainstream impact evaluation in the project cycle, ADB approved in 2010 a technical assistance on Implementing Impact Evaluation at ADB (TA 7680).
A technical assistance project on developing impact evaluation methodologies, approaches, and capacities in selected DMCs is in progress. This project involves a series of impact evaluation studies over an extended period in various DMCs. The subprojects will facilitate learning by DMCs from experiences on the effectiveness of interventions, thereby effecting technology and/or knowledge transfer between and among DMCs and ADB.