"The United States' failure to educate its students leaves them unprepared to compete and threatens the country's ability to thrive in a global economy." Such was the dire warning recently issued by a task force sponsored by the Council on Foreign Relations. Chaired by former New York City schools chancellor Joel I. Klein and former U.S. secretary of state Condoleezza Rice, the task force said that the country "will not be able to keep pace--much less lead--globally unless it moves to fix the problems it has allowed to fester for too long. The report's views are well supported by the available evidence. In a 2010 report, only 6 percent of U.S. students were found to be performing at the advanced level in mathematics, a percentage lower than those attained by 30 other countries. Nor is the problem limited to top-performing students. Only 32 percent of 8th-graders in the United States are proficient in mathematics, placing the United States 32nd when ranked among the participating international jurisdictions. Although these facts are discouraging, the United States has made substantial additional financial commitments to K-12 education and introduced a variety of school reforms. Have these policies begun to help the United States close the international gap? To find out the extent of U.S. progress toward closure of the international education gap, the authors provide estimates of learning gains over the period between 1995 and 2009 for the United States and 48 other countries from much of the developed and some of the newly developing parts of the world. They also examine changes in student performance in 41 states within the United States between 1992 and 2011, allowing them to compare these states with each other. Their findings come from assessments of performance in math, science, and reading of representative samples in particular political jurisdictions of students who at the time of testing were in 4th or 8th grade or were roughly ages 9-10 or 14-15. The gains within the United States have been middling, not stellar. While 24 countries trail the U.S. rate of improvement, another 24 countries appear to be improving at a faster rate. Nor is U.S. progress sufficiently rapid to allow it to catch up with the leaders of the industrialized world. Student performance in nine countries declined over the same 14-year time period. Test-score declines were registered in Sweden, Bulgaria, Thailand, the Slovak and Czech Republics, Romania, Norway, Ireland, and France. The remaining 15 countries were showing rates of improvement that were somewhat lower than those of the United States. Progress was far from uniform across the United States, however. Indeed, the variation across states was about as large as the variation among the countries of the world. The states making the largest gains are improving at a rate two to three times the rate in states with the smallest gains. States that were further behind in 1992 tend to make larger gains than initially higher-performing states. However, their initial level of performance explains only about a quarter of the variation among the states. Also, variation in state increases in per-pupil expenditure is not significantly correlated with the variation in learning gains. States with the largest gains in average student performance also tend to see the greatest reduction in the percentage of students performing below the basic level. They also are the ones that experience the largest percent shift of nonproficient students to the level of proficiency set by NAEP (National Assessment of Educational Progress). However, there are some exceptions to this overall pattern. At the 8th-grade level, the gains by educationally disadvantaged students in Texas were larger relative to other states, given the percentage of nonproficient students who attained NAEP proficiency. Conversely, nonproficient students in Utah, Nebraska, Pennsylvania, Maine, Wisconsin, and Minnesota were more likely (relative to other states) to cross the proficiency bar, given the gains being made by the most educationally disadvantaged students. Otherwise, an educational tide within a state that lifted an average boat lifted all boats fairly uniformly. Appended are: (1) Estimating Trends across Countries and across U.S. States; and (2) Alternative Estimations of Trends. (Contains 14 figures, 2 tables, and 32 footnotes.