ABSTRACT
Trends in socioeconomic achievement gaps—the achievement disparities between children from high- and low-income families or between children from families with high or low levels of parental educational attainment—have received attention. To compare the size of the achievement gap across studies, the author reports test-score differences between groups in standard-deviation units, adjusted for the estimated reliability of each test. Possible explanation for the rising income achievement gap is that high-income families not only have more income than low-income families but also have access to a range of other family and social resources. The gap between the rich and the poor has widened significantly, particularly among families with children. The evidence thus far indicates that the relationship between a family's position in the income distribution and their children's academic achievement has grown substantially stronger during the last half-century. Some studies of peer effects find evidence that the academic-achievement level of one's classmates may impact one's own achievement.
