The real reason American high-schoolers have such dismal test scores.

If you believe in test scores—and education policymakers seem to believe in little else these days—American high-school students are a pathetic bunch. Witness the results of National Assessment of Educational Progress (or NAEP)—the "nation's report card"—which were released last month. While younger students broke records in both math and reading, 17-year olds' scores as a whole showed no improvement from the early 1970s.