On the 2015 Program for International Student Assessment’s math tests for 15-year-olds, Canada ranked 9th, while the United States ranked 39th. Continuing “business as usual” puts the U.S. well below the average math-skill level in developed countries, faring only slightly better than countries such as Croatia and Greece—two nations with low PISA scores and struggling economies. By historic patterns, if the U.S. were to close just half the gap between U.S. students’ PISA scores and Canada’s, it would raise the average U.S. gross domestic product 7 percent across the 21st century—more than enough to pay for projected fiscal problems with Medicare and Social Security benefits. Such monetary improvements would be more than 10 times larger than the economic losses from the 2008 recession. To learn more about how the U.S. can improve schools—and economic outcomes—read Eric Hanushek’s “What Do Test Scores Really Mean for the Economy?” on EdNext.org.