Implementing Impact Evaluation at ADB

Impact evaluations provide empirical evidence showing whether development interventions result in measurable impact and greater aid effectiveness.

Impact evaluations provide empirical evidence regarding the outcomes or results attributable to development projects. Evidence on what works and does not work is important in improving accountability and learning from the development interventions. Before-after comparisons or comparisons between areas with and without projects often lead to false conclusions about project effects, because the differences observed are due to many other factors than the project alone. Impact evaluation offers a set of tools to separate the consequences of projects from other drivers of change, in order to understand what changes are truly attributable to projects. Impact evaluation has a variety of applications: from understanding which approach to an intervention is most effective, to ascertaining causal relationships that will effectively reduce poverty. All impact evaluation techniques are premised on the concept of a “counterfactual”, which is either identified as a randomly selected “control group” and is approximated econometrically.

Implementing impact evaluation at ADB

Although impact evaluation is a growing field, there remains little evidence about the contribution of individual infrastructure projects and programs, which receive a majority of ADB’s finance, to development goals. Moreover, there are many choices and assumptions that underpin the designs of projects in all sectors, of which few are empirically tested. More systematic measurement of project/program outcomes through impact evaluation supports evidence-based policymaking and helps development partners design and implement projects more effectively. ADB recognizes that impact evaluation will help ADB and its developing member countries (DMCs) allocate limited resources more efficiently, guide the design of more effective interventions and enable evidence-based policy.

In line with its priority on managing for development results and mainstreaming impact evaluation in the project cycle, ADB approved the following technical assistance projects.

Ongoing and pipeline IE studies under TA 7680 and TA 8332





Viet Nam


Sri Lanka

Papua New Guinea

Progress of ongoing studies under TA 7680 and TA 8332


Other ongoing ADB IE studies

Completed ADB IE studies


Potential IE partners


This page was generated from on 29 March 2015