Assessing the contribution of donor agencies to aid effectiveness: The impact of World Bank preparation on project outcomes

This paper assesses the impact of World Bank project preparation on project outcomes. Using a stochastic frontier model, I generate a measure of World Bank project preparation duration based on variation in political economy factors that are otherwise exogenous to project outcomes. Panel analysis of project data finds that projects with longer preparation periods are significantly more likely to have satisfactory outcome ratings. This result is robust across a range of specifications but the effects are conditional on the degree of economic vulnerability. The impact of World Bank preparation is greater in countries experiencing debt problems. The impact of donor preparation identifies a positive contribution of development aid that is not subject to the usual fungibility critique.