While there are strong theoretical arguments for ways in which public spending influences growth, robust empirical links have been difficult to establish. More recently, many of the methodological problems that plagued the earlier literature have been overcome and interesting policy lessons drawn. The number of studies of developing countries using these new approaches is still limited, due to data scarcity and other comparability issues, but overall findings from the new literature are relevant for developing country policy makers and also open new venues for future research. The objective of this note is to present these new empirical results together with the methodological improvements that support them, and to outline some of the issues that need deeper analysis and empirical study, particularly in developing countries.