It’s a foundational premise of the American dream: that through hard work and diligent study, young people can use education to access opportunities that were denied to their parents. However, mounting evidence suggests that segregation — not just by race, but also by income — within the school system may stymie those meritocratic aspirations.

Income-based school segregation has been steadily increasing over the last 30 years, studies show. But while researchers have previously demonstrated that low-income students are increasingly attending different schools than their more affluent peers, a new working paper published by the Annenberg Institute at Brown University finds that income segregation within schools, from classroom to classroom, is also on the rise.

“People are familiar with the idea of school segregation at the building level, but then we often see even within integrated school buildings, resegregation at the classroom level,” said Kahlenberg, a senior fellow at The Century Foundation. “Low income students, disproportionately students of color, end up in remedial or basic classes.”

The trends identified by the American University team held true even while controlling for students’ racial identity.

Of course, identifying trends in income segregation is one thing. Achieving integrated schools and classrooms is quite another. Kahlenberg, however, has a few ideas for where to start. “We need new tools to address economic housing segregation,” he said.

Even after striking down unconstitutional zoning laws that excluded residents by race, the U.S. has not removed zoning laws that discriminate by wealth. “Very commonly, we have communities that are engaged in exclusionary zoning, where they say, ‘You can only live here if you have the money to buy a single-family home. If you can only afford a duplex or a triplex, we don’t want you,’” explained Kahlenberg.

Read the full article about income segregation in education by Asher Lehrer-Small at The 74.