What a New Harvard Study Shows About Student Performance in Charter Schools

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Black student in classroom with iPad

The evidence—both anecdotal and quantitative—has consistently shown that public charter schools use the flexibilities in their school models to best serve students, especially those who are historically underserved by public schools. Now we have even more.

A new study from Harvard University’s Program on Education Policy and Governance leverages data from the National Assessment of Educational Progress (NAEP) to look at trends in charter school student performance compared to district school students. The results are significant and demonstrate how charter schools have improved as a sector and made a significant positive impact on students.

At the National Alliance we follow studies of student achievement at charter schools closely: this is the first nationally significant study since 2015. But not only is it a key update, it looks at charter school performance in new ways, utilizing data from the National Assessment of Educational Progress that have only recently become available to researchers. Here are some of the most significant findings:

1. This is the first study to use nationally representative data to track changes in student achievement within public schools.

This is important because the authors look at the pace of improvement—student performance growth over time. Up until now studies have typically compared the average performance of students. With that lens, the findings show the pace of improvement in charter schools is faster over the 12-year span. The sample examined by the researchers include more than 4 million test performances.

2. Charter schools have improved over the years.

On average, district schools outperformed charter schools in 2005 in both the 4th and 8th grades—particularly in math. By 2017 those differences had disappeared. While the study doesn’t address all the possibilities explaining the improvement, it suggests the closure of lower performing schools and replacing them with more effective ones is a factor.

3. Overall students are advancing at a faster pace in charter schools – especially Black students and students from low-income backgrounds.

Overall eighth graders attending charter schools show learning gains that are 3 months ahead of their district school peers from 2005 to 2017. Black students in particular were an additional 6 months ahead. Given that one in three charter school students is Black, this is especially noteworthy. Scores of those in the bottom 25% of the socioeconomic distribution increased nearly twice as much as those of students in district schools.

4. Charter school growth slowdowns are likely due to political resistance and increasing concerns about the charter schools as innovative disrupters.

One reason the authors undertook the study was to identify whether performance is tied to the decline in new charter school growth that we’ve seen since 2017. And their findings show that the answer is no. Given rising achievement levels at charter schools—it is unlikely that any slowdown in growth is due to declining productivity.

What the data from this study shows us is that—as we have already seen in prior research—charter schools are largely working for students, but especially students who are historically disadvantaged. In addition, aligns with the findings from a recent study from Bellwether Education Partners looking at federal funds for opening up new charter schools and how it has evolved and contributed to opening more high-quality schools.

Taken together, the research shows charter schools are finding what works through innovation, replicating their success, and ultimately producing accelerated achievement gains for students.


Christy Wolfe is the vice president of policy and planning at the National Alliance for Public Charter Schools.


Take a look at a summary of the Harvard research on student performance.