New data from the Institute on Race and Poverty at the University of Minnesota Law School shows most charter schools in the Twin Cities underpreform and are more highly segregated than public schools.

The study shows that a very high proportion of charter schools are single-race schools. 

“The high rates of racial and economic segregation matter because research shows that students do worse in segregated school environments than in integrated settings,” said Tom Luce, research director of the institute. “Given that, it’s not surprising that this work, along with virtually every other comprehensive study of charter schools in Minnesota, shows that charter schools are outperformed by their traditional counterparts in standardized testing, even after controlling for school characteristics such as poverty.”

The study did recognize a few charter schools with high test scores, but charter schools as a whole score much lower than public schools.

“Despite some significant changes in the state’s charter laws aimed at improving accountability in charter schools—at least partly as a result of studies like our 2008 report—charter schools as a group continue to fail to meet the academic and social objectives set forth by proponents,” Myron Orfield, director of the Institute on Race and Poverty, said in a news release.