Abstract: | This article analyses evidence for each of the expected benefits of budget support in turn, and finds the biggest improvements in the pro‐poor nature of public expenditure and public financial management. More modest improvements are noted in the predictability of aid and the burden of transaction costs, while less is known about the real effects on domestic accountability. Underlying them all is an assessment that programmes are incapable of ‘buying’ reforms. Drawing on the analysis, seven areas are highlighted where budget support design can be strengthened vis‐à‐vis its original rationale. |