The World Bank has been criticized ever since its creation in 1944. Liberals and conservatives alike have charged the Bank with many sins: from being an unmanageable inefficient bureaucracy with a bloated staff of more than 10 000, to having a mission that is ideologically confused. One of the commonest complaints is that billions of dollars are thrown at aid projects with little if any evidence of efficacy. To counteract these charges the Bank has invested heavily in public relations, but it has so far avoided asking the question: does its approach really work?