It might also mean greater business and government support for maternity and paternity leave and day care so that the middle class and the poor can g… - Sean Reardon

What is news is that in the United States over the last few decades these differences in educational success between high- and lower-income students have grown substantially. We are still talking about this despite decades of clucking about the crisis in American education and wave after wave of school reform. Whatever we’ve been doing in our schools, it hasn’t reduced educational inequality between children from upper- and lower-income families. Part of knowing what we should do about this is understanding how and why these educational disparities are growing.

But rising income inequality explains, at best, half of the increase in the rich-poor academic achievement gap. It’s not just that the rich have more money than they used to, it’s that they are using it differently. This is where things get really interesting. High-income families are increasingly focusing their resources — their money, time and knowledge of what it takes to be successful in school — on their children’s cognitive development and educational success. They are doing this because educational success is much more important than it used to be, even for the rich.

If not the usual suspects, what’s going on? It boils down to this: The academic gap is widening because rich students are increasingly entering kindergarten much better prepared to succeed in school than middle-class students. This difference in preparation persists through elementary and high school. As you may have heard, the incomes of the rich have grown faster over the last 30 years than the incomes of the middle class and the poor. Money helps families provide cognitively stimulating experiences for their young children because it provides more stable home environments, more time for parents to read to their children, access to higher-quality child care and preschool and — in places like New York City, where 4-year-old children take tests to determine entry into gifted and talented programs — access to preschool test preparation tutors or the time to serve as tutors themselves.