This is a cached copy of the WSJ report (which is no longer available online). Published 11 September 2013. Data from 50 countries over half a century reveal how even a small education gain can mean a big economic payoff. Americans are aware of public education's many failures—the elevated high-school dropout rates, the need for remedial work among entering college students. One metric in particular stands out: Only 32% of U.S. high-school students are proficient in math on the National Assessment of Educational Progress. When the NAEP results are put on the scale of the Program on International Student Assessment (PISA), the world's best source of information on student achievement, the comparable proficiency rates in math are 45% in Germany, 49% in Canada, and 63% in Singapore, the highest performing independent nation. The subpar performance of U.S. students has wide ramifications—and not just for individuals. On an individual level, of course, the connection between education and income is obvious. Those with a college degree can expect to earn over 60% more in the course of their lifetime than those with a high-school diploma, according to U.S. Census data. But there is a nexus between educational achievement and national prosperity as well.According to our calculations, raising student test scores in this country up to the level in Canada would dramatically increase economic growth. We estimate that the additional growth…