Has the gap in average standardized test scores between students from high- and low-income families widened, narrowed, or remained stable over the last 3 decades? The question is important both because the achievement gap is measure of how (un)equally educational opportunities are distributed in the US, and because the disparity in educational…

Richard Murnane observes that the American ideal of equality of educational opportunity has for years been more the rhetoric than the reality of the nation's political life. Children living in poverty, he notes, tend to be concentrated in low-performing schools staffed by ill-equipped teachers. They are likely to leave school without the skills…