What have we learned across the three studies?

We have now undertaken three studies examining the impacts of the national charter sector on the academic progress of the students. Across each educational study, we have examined charter school learning results over 15 of the 30 years that charter schools have been in existence, starting in 2004 and ending in 2018–19. In 2009, we released the first research of this kind examining the quality of charter schools using data from 16 states, with findings highlighting the need for further inquiry into charter school quality.

The second study in 2013 included 27 jurisdictions: 25 states, Washington, DC, and New York City (due to its size and presence of policies that differed from the state). That educational study saw improved performance among charter school students compared to the 2009 study and positive gains on average for charter students compared to their traditional public school (TPS) peers in reading. This 2023 study is the follow-up to and expansion of the previous two studies. It takes us up to the last pre-COVID-19 year of data, 2018–19, and sets a baseline from which to compare post-pandemic results.

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Though the outcomes of these studies are largely positive, they also support several conclusions about the current landscape of charter schools across America. Perhaps more importantly, the opportunity to position these findings in the larger body of research leads to a number of implications for the fundamental policies and practices of charter schooling at a more global level.

In both reading and math, charter schools provide students with stronger learning compared with the learning in the TPS that are otherwise available to them.

Across the broad range of charter schools, the evidence suggests they are a robust education option under many conditions. Whether stand-alone or networked, charter schools operate by law mainly on their own, making decisions they expect will serve their students well. According to our latest findings, the autonomy given to them usually yields positive results. The majority of charter schools provide better year-to-year outcomes for students compared to their TPS options. Most of these schools perform better to such a degree that the difference is statistically significant. 

The results stand up to deeper investigation. Charter schools produce superior student gains despite enrolling a more challenging student population than their adjacent TPS. They move Black and Hispanic students and students in poverty ahead in their learning faster than if they enrolled in their local TPS. They are more successful than the local TPS alternatives across most grade spans and community settings. These results show charter schools use their flexibility to be responsive to the local needs of their communities.

Some charter schools provide less student learning than their local district schools, although a larger proportion delivers better learning outcomes. The latter group includes more than 1,000 charter schools managing staffing and resources to deliver superior academic results, eliminating the learning gap across student groups.

Vital lessons also come from the distribution of school performance around the average. Over the past 30 years, small, large, urban, rural, networked or stand-alone charter schools (SCSes), autonomous and independent of each other, have arrived at their own solutions for giving their students stronger learning experiences. The discretion that charter schools enjoy does not guarantee each school or every charter network realizes strong student outcomes. Our educational study illuminated the range of learning across schools. 

Despite declining shares, there are significant numbers of charter schools with weaker student outcomes. While lower-performing schools make up a larger share of SCSes, charter management organizations (CMOs) and networks also have a substantial share that produces low gains for their students. As our analysis shows, disturbing numbers of charter schools and networks have low learning levels. There are brick-and-mortar, online, networked and SCSes with sub-par results. 

The number of school closures we observed in the years of the educational study was small compared to the counts of schools with the lowest student growth and academic achievement. Especially in the post-pandemic era, the need for charter boards and authorizers to address under-performance in their schools has never been more critical. 

Closure is not the sole remedy. As we learned from our special investigation, the takeover of underperforming schools by strong CMOs led to improved student learning for the students who remained enrolled before and after the transfer. The gains did not adversely affect student academic progress in the rest of the CMOs’ schools. This policy tool may have broader utility than previously realized. 

At the high end of the performance range, good news exists in the growing share of schools outpacing learning in their local TPS. In both subjects and for both CMOs and SCSes, larger shares are “better than” and a smaller share is “weaker than” compared to earlier work. 

The real surprise of the educational study is the number of charter schools that have achieved educational equity for their students — we call them “gap-busting” schools. Ensuring equivalent yearly growth across student groups has two critical consequences: First, ensuring minority and poverty students learn on par with or better than their White peers interrupts or reduces the achievement gap. It happens regularly in a large swath of charter schools. More critically, there is strong evidence that these gap-busting schools can be scaled. Added to the TPS that achieve similar results, this is the life-transforming education that so many students need. Second, these schools deliver hundreds of independent proof points that learning gaps between student groups are not structural or inevitable; better results are possible. 

The larger scale of CMOs does not guarantee high performance — but on balance, it helps.

When taken as a whole, schools managed by CMOs and charter networks bring a greater learning benefit to students compared to SCSes. Despite the differences, both groups of charter schools have had larger student success than TPS with respect to reading. We note, however, that math gains in SCSes were equivalent to TPS learning. 

Our analysis highlights attributes of higher-performing CMOs and networks that could be useful in future discussions. The size or age of the CMO does not relate to student learning; at every increment of CMO age or portfolio size, we see high- and low-impact CMOs and networks. This further supports earlier our research that showed CMOs only replicate the quality they already have. The implications of replicating schools with weak results are clear. The big upside is the ability of dozens of CMOs to scale their gap-busting performance. Additionally, CMOs that concentrate their operations within a single state have stronger gains than multistate CMOs, though both groups do well by their students. 

Programs of external funding and support to CMOs to grow their networks focus on some of the stronger CMOs and networks in our educational study. After high-performing CMOs receive an endorsement, the learning of students in those CMO schools rises in reading but holds steady in math. 

Charter schools and networks, as do the systems that oversee them, improve over time.

Insights about improvement in schools and networks stem from this educational study and our prior multi-state studies. 

In the years of this study, student growth in charter schools was the strongest observed in any of our multi-state studies. Added to the results from the previous two studies, a strong trend of improvement becomes clear. We see substantial increases in student learning in CMOs in both tested subjects and in reading for SCSes. Even the finding of no difference in math learning in SCSes vis a vis TPS, a decline from the 2017 study results, still marks an improvement from the statistically significant negative results in the first CMO versus stand-alone comparisons in 2013. 

A better understanding of the improvement in the sector comes from two different findings. The first is that the largest share of improvement comes from existing charter schools. Compared to the National Assessment of Education Progress (NAEP) trend, evidence of schools getting better over time is welcome news. 

Second, new schools opened with stronger results than at any time in the past. Growth in the number of CMOs since the last study plays a role. Many SCSes also pushed their results upward. Strengthening authorizer standards and practices, a drive that took root in the 2010s, also sets a higher bar that resulted in better schools opening. 

Implications from our educational study

The charter school policy framework sets the conditions for charter schools’ growing positive outcomes. It is the fundamental common denominator in every case and its role is powerful.

The framework offers a divergent approach from the conventional strategy for public schools. The “flexibility for accountability” construct is not just a catchphrase. It is a distinctly different mode of operation. The “loose-tight” parameters of the framework create incentives to which schools and networks respond. The incentives find positive support in this study’s findings and the broader trends. While our educational study design cannot make causal claims (because randomly assigning schools to either the traditional or charter school approach has yet to happen), it can deliver a plausible argument of the value of the policy based on available evidence.

On the “loose” side of the approach, the framework establishes a policy of possibility where educators, leaders and boards of directors have the discretion to build and deliver curriculum and instruction that meets high standards for learning and is responsive to local needs.
According to this study, there are a lot of positive possibilities. The diversity of schools with positive results illuminates an important feature of the framework: success is attainable via many paths.

Students in these schools, especially minority students and those in poverty, make larger advances than in local public schools. Beyond the benefits for their students, successful charter schools deliver critical proof points of ways to improve outcomes for students.

Beyond flexibility in school design, school teams have the leeway to tinker with their operations. The results show that existing charter schools have improved over time. The proportion of charter schools with superior results is on the rise. The share that lags behind the local TPS alternatives is also shrinking. This means schools and networks use their discretion and autonomy to foster a standing capacity to adapt over time.1

Accordingly, the framework also aims to be “tight” at key points as schools open and mature. Authorizers are expected to behave as governors of quality. They set the bar to receive initial permission to operate, which exerts quality and safety controls at the outset. Others have documented stronger standards among authorizers in the review and approval of new applications (Mumma & West, 2018). The findings of stronger new schools in this study compared to earlier results attest to the effort and to the CMO replications and new charter schools that meet the higher bar.

Authorizing is a delicate job that requires resources, expertise and substantial political acumen and courage. There is growing attention to authorizers adopting rigorous standards and practices and using a variety of performance data to evaluate schools that apply for renewal (NACSA, 2016).

Poorly performing charter schools are often ignored. A number of these schools were observed during this study window. There is data to assess policy leaders and authorizers to hold them accountable for protecting children’s futures. As tough as closing schools is, the disservice of not closing poorly performing schools has large and lingering ripple effects.

Our results show that the framework of charter schools helps current students and strengthens public education overall. We contend these incentives have broader applicability in public schools and see signs of their spread. Collaborations between charter schools and local district schools have grown over time. Some states, including Kentucky and Maine, have adopted policies to give educators freedom in adjusting instruction and boosting performance. However, uptake is slow.

In the year 2023, the importance of strong academic achievement among America’s students has never been greater. The students hit hardest by school closures during the coronavirus pandemic are precisely those whom this research illuminates as being able to benefit most from the charter school system. In this study, thousands of charter schools have proved that we can do better for our students. The current number of students benefiting from these schools is 3.7 million, but the number could drastically increase if more schools agreed to the same arrangement. Whether it be termed “charter school” or something else, the deduction from this data is that when both sides of the equation — flexibility and accountability — are working together for more schools, more students’ academic results will improve.

1 We saw that capacity in stark terms when we examined how charter schools in three states responded to the COVID-instigated school closure orders (CREDO, 2022). Rapid transformation into remote instructional mode; acquisition and distribution of food, technology, or internet access; and strengthening of personal supports were widespread. Return to in-person instruction in the fall of 2020 was nearly universal. These points rest admittedly on smaller bases of qualitative evidence, but they provide human dimensions to the point that the present quantitative analysis illuminates nationally. See also: Boast et al. (2020); Henderson et al. (2021); Childs et al. (2022).

Explore the written reports

STUDY I – 2009 National
Charter School Study

STUDY II – 2013 National
Charter School Study

STUDY III – 2023 National
Charter School Study