In a society of limited resources and increasing demand, education systems need to focus on efficiency as well as outcomes. In the business world, this is often referred to as return on investment (ROI). How do education outcomes relate to spending? Which education systems get the greatest results for dollars spent? The data suggest that spending alone does not necessarily result in improved outcomes. An increasing amount of evidence reinforces the conclusion that funding alone has no direct relationship to school success. The lack of a direct link between per-pupil spending and education outcomes is apparent at all levels of macro analysis: international, national, state, and local district. In 2015, the United States ranked third in per-pupil spending among the 34 countries in the Organisation for Economic Co-operation and Development (OECD), yet among these nations ranks 25th in science, 22nd in reading, and 38th in mathematics. Per-pupil funding at the national level has increased in real dollars with virtually no improvement in National Assessment of Educational Progress (NAEP) academic scores. Individual state and district per-pupil funding vary dramatically, with no correspondence to student performance.