New research on the state of U.S. education shows that income inequality has surpassed racial inequality as the single most significant predictor of education outcomes. According to the Russell Sage Foundation, the achievement gap between rich and poor students is now larger than the gap between white and black students—perhaps a watershed moment in the changing discourse on inequality.

Century Foundation Senior Fellow Richard Kahlenberg weighs in on the debate in the post below, describing a few of the myriad strategies that TCF and other organizations have proposed to close the socioeconomic achievement gap in education. But I wanted to highlight a few of Kahlenberg's own graphs, from Rewarding Strivers: Helping Low-Income Students Succeed in College, which illustrate a few of the ways in which income inequality critically disadvantages students at the bottom of the income distribution.

Much of the funding for public schools typically comes from local property taxes, leaving poorer districts with significantly lower-quality staff and facilities than wealthier districts. The table above shows how teacher quality drops at high-poverty schools, while the number of students who will grow up to live in poverty skyrockets from 4 percent to one in seven—even when controlling for individual ability and family home environment.

But the disadvantages don't stop there. Kahlenberg's research for The Century Foundation also indicates that students from the bottom income quartile received zero or negative advantage in the college admissions process, while recruited athletes, minority groups, and legacies enjoyed a significant boost. Leaving aside the issue of athlete and legacy preference, which Kahlenberg has argued against forcefully in the past, it is disturbing, in light of this new research, why few schools have adopted programs to encourage economic diversity.