Although there is intense policy interest in improving educational outcomes around the world, there is much greater uncertainty about how to accomplish this. The primary governmental decisions often relate to the resources that are devoted to schooling, but the research indicates little consistent relationship between resources to schools and student achievement. Much of the research considers how resources affect student achievement as measured by standardized test scores. These scores are strongly related to individual incomes and to national economic performance, making them a good proxy for longer run economic impacts. But, the evidence - whether from aggregate school outcomes, econometric investigations, or a variety of experimental or quasiexperimental approaches - suggests that pure resource policies that do not change incentives are unlikely to be effective. Importantly, the results appear similar across both developed and developing countries.