National study: Over 1.8 million charter school students outperform peers at traditional public schools
Over the course of 15 years of studies, charter school students have gone from lagging their traditional public school peers in both math and reading to outperforming them.
Starting in 2009, a comprehensive national analysis by Stanford University’s Center for Research on Educational Outcomes (CREDO) found that charter schools underperformed traditional public schools in both math and reading. A follow-up study in 2013 showed charter school students doing slightly better than their traditional public school counterparts in reading but still lagging them in math.
Fast forward to today’s 2023 study by CREDO and charter school students now average more learning in both reading and math than traditional public school students — in the aggregate and across student race/ethnicity groups. (For Minnesota specific, its charter schools included in the analysis posted better gains in both reading and math compared to its public schools.)
What changed? Charter schools got better.
Over time, charter schools have improved, as have the systems that oversee them, write the authors.
And it’s not because they just enroll smarter students, point out the authors. In fact, their analysis found that charter schools “enroll students who are disproportionately lower achieving than the students in their former traditional public schools.” Charter schools don’t get to select their students, either, notes Jonathan Chait in the New York Magazine.
Are there outliers? Yes, as special education students attending stand-alone charter schools had less growth than their public school special education peers (special education students in charter schools associated with charter management organizations performed on par with those peers), but even so, what CREDO’s comprehensive analysis shows is that charter schools do “offer a promising model for closing the achievement gap,” Chait continues.
Annual Academic Growth of Charter School Students Across Three National Studies (2009, 2013, 2023)
From 2015 to 2019, the average charter school student advanced their learning by an additional six days in reading and 16 days in math compared to their peers in traditional public schools. There were more than 1,000 charter schools in the study that eliminated academic learning gaps across student groups and “moved their achievement ahead of their respective state’s average performance,” the authors point out. (This is important because closure of academic achievement gaps doesn’t always mean student scores are going in the right direction.)
So, why then, do teachers’ unions and others bent on convincing the public they are “for the kids” oppose them? [Insert obvious answer here.]
The research data set includes data from 29 states plus Washington, D.C. and New York City, representing 81 percent of tested public school students in the United States and “one of the largest data sets of student-level observations created to date,” note the authors. The matched student data set includes 6.5 million student-level observations from nearly 1.9 million charter school students and a matched comparison group. Additionally, the methodology includes matching
each charter student whose records appear in the data with records of traditional public school students with identical traits and aligned prior test scores who enrolled in schools that the charter student would have attended if not at their charter school. This approach, the Virtual Control Record protocol, creates a “virtual twin” to a charter school student. For research purposes, the virtual twin differs from the charter student only in the school attended. … To assure accurate estimates of charter school impacts, we use statistical methods to control for differences in student demographics and eligibility for categorical program support such as free or reduced-price lunch eligibility and special education. In this way, we have created the analysis so that differences in the academic growth between the two groups are a function of which schools they attended.
At the end of the day, opponents of charter schools have even less evidence to support their anti-education reform efforts and supporters of school choice have more credible evidence to support the importance of helping families access alternatives to traditional public schools.