Public school funding in the United States is not a product of intelligent design. Funding programs have grown willy-nilly based on political entrepreneurship, interest group pressure, and intergovernmental competition. Consequently, now that Americans feel the need to educate all children to high standards, no one knows for sure how money is used or how it might be used more effectively. This article shows that Americans can learn how to make more effective use of the money available for public schools. But to do so, states and localities must keep careful track of how money is spent; how children are taught and by whom; and what programs, schools, and teachers are most and less productive. Foundations should sponsor rigorous development and testing of new instructional programs, and every level of government should permit experimentation with alternative uses of funds, reproduce effective schools and programs, and abandon ineffective ones.