Former U.S. Secretary of Education, Arne Duncan, spoke out last month in favor of public charter school education. Duncan believes those schools especially help students in low-income areas.

Charter schools have proved a controversial topic within education administrations, as they are often criticized for lacking in basic courses for reading and math, while others exist simply to turn a profit without actually helping students. But Duncan believes that when they are run well, charter schools can be a wonderful resource for students and families.

Duncan, who was recently recognized for his contributions to education at the Sponsors for Educational Opportunity’s 13th Annual Awards Dinner, an event chaired by Ken Mehlman, spoke at an event hosted by the Brookings Institution. Duncan said that he believes charter schools offer real benefits to their communities. “I think we have more charters that are making a real difference in kids’ lives, however you define it, and that’s a great thing.” Duncan referred to studies that indicate students who attend charter schools tend to earn more over their lifetimes and do better academically.

Charter schools are typically publicly funded and don’t charge tuition. Typically, “charter school” refers to an independent school established by communities under the terms of a particular authority, or “charter.” They also offer more flexible hours and independence of students, making them a popular choice for families. However, charter schools are not without their drawbacks. One report indicated that charter schools’ test scores only reflected minimal levels of academic success and that charter schools in Pennsylvania covered 29 fewer days of reading material than other public schools. Other accusations allege that charter schools are sometimes “cash cows,” earning investments from politicians—which is problematic on several levels.

Still, Duncan believes in the potential of the charter school. He said that he believes it was a good thing that many charter schools have closed in the last several years because that will allow administrations to focus on quality rather than quantity. Duncan retired from his position at the end of 2015, after which President Obama said that Duncan has “done more to bring our educational system, sometimes kicking and screaming, into the 21st century more than anyone else.”

Duncan has since joined Brookings as a nonresident senior fellow in their Brown Center on Education Policy.