Evaluating Aid Impact

This paper outlines recent developments with a methodological review of approaches to
impact evaluation, drawing on studies from a number of agencies. The paper argues
that, whilst technical rigour is important, it is at least as important to not lose sight of
policy relevance, which is achieved by avoiding ‘black box’ approaches. Section 2
discusses basic concepts and principles in impact evaluation, and section 3 the
approaches to measuring impact. Both sections draw on experiences of a number of
official agencies in evaluating aid impact, most notably the Independent Evaluation
Group (IEG, formerly Operations Evaluation Department, OED) of the World Bank.
Section 4 concludes, arguing that, properly done, impact evaluation not only provides
evidence as to whether aid works but also how to make it work better.