What is impact analysis?
|Datum:||02 december 2018|
|Auteur:||dr. Hanna Fromell|
To justify the continuation or adjustment of a development program or a policy, evaluations are commonly used to answer whether the intended outcomes are reached. Such outcomes can for example be an improvement of health, increase in productivity, or raise of income.
Impact evaluations represent a branch of evaluation methods that in recent years have gained widespread acceptance and been advocated for by key agencies such as the World Bank and the UN. The strength of impact evaluations are largely their ability to determine a causal relationship between a specific program and its intended outcomes. This allows for addressing transparency, accountability and lesson learning; all which are of key interest to stakeholders. By comparing a program to a counterfactual, while addressing potential selection bias and contamination problems, impact evaluations can estimate the average effect due to the program on the welfare of program participants. Where sample sizes are large enough and detailed data is available, the question of whom among the participants benefits more and whom that benefits less can be addressed. Impact evaluations can also be used to perform cost-effectiveness analysis that allow for comparison of which of several program alternatives achieves intended outcomes at the lowest cost. Impact evaluations are preferably initiated before the start of the program since the problem of selection bias can be overcome via a randomized design. However, a series of techniques can be used to determine causal relationships also after program start, such as quasi-experimental design or a pipeline approach.