the third grade, children who once were enrolled in. Head Start perform no better 011IQ tests than those who were not. Currie, of the National Bu- reau of Economic Research, and Thomas, of Yale University's Eco- nomic Growth Center, sought to take a broader measure of Head Start's effect-on success in school, on various comprehen- sion tests, and on health. They found, surprisingly, that Head Start does make a difference but that its effects vary race.
Using data from the National Longitudinal...