Many people would argue that U.S. elementary and secondary public schools need to improve, and they would like to see U.S. students perform better in international comparisons. In addition, many people would like to do more to close the achievement gaps within the U.S. between lower-income and minority students and their counterparts. These concerns are shared by parents, employers, policymakers and society more generally. There is less agreement on the root causes of the problems and how best to tackle them. For example, while some would argue that insufficient funding is the primary factor, others would say that this is not supported by the evidence, since per pupil spending has increased faster than achievement, as reflected in scores on the National Assessment of Educational Progress (NAEP).