Conventional wisdom holds that public education demands uniformity, yet a growing sector is actively dismantling that assumption. Charter schools publicly funded institutions operating with significant autonomy are rapidly reshaping the landscape of American education. These schools, chosen by families rather than dictated by zip code, now educate a surprising 3.7 million students, representing 7.4 percent of the nation's public school enrollment.
The movement is charter schools, and few people have watched its evolution more closely than Nina Rees, who served as president and CEO of the National Alliance for Public Charter Schools from 2012 through the end of 2023. In that time, she became the public face of a sector that has reshaped debates about school choice, accountability, and what public education can look like when it is freed from some of the constraints that govern traditional district schools.
"I have always thought of [charter schools] as laboratories of innovation with the hopes of replicating those innovations in district-run schools," Rees told Education Week in a December 2023 interview. That framing laboratories of innovation captures something essential about how the charter movement has understood itself, and how it has tried to position itself within the broader landscape of American public education.
From Niche Experiment to National Sector
The charter school idea has been part of American education policy since the early 1990s, when the first charters were granted in Minnesota and California. The concept was straightforward: give independent operators the freedom to run schools differently, in exchange for higher accountability for results. If a charter school failed to deliver, it could be closed. If it succeeded, it might offer a model worth copying.
For years, the sector grew steadily but remained a relatively small part of the overall public education system. Then something shifted. According to federal data cited by Education Week, charter school enrollment more than doubled from the fall of 2010 to 2021. That is not a marginal increase it is a structural change in who is attending what kind of school. By 2023, the sector had reached nearly 8,000 schools, and it was the only segment of the public school system that was growing.
"The charter school movement has serious momentum behind it," Rees said in a 2024 interview with Rick Hess of the American Enterprise Institute, published in Education Week. "It is the only segment of the public school system that is growing, we've had multiple legislative victories at the state level in 2023, and CREDO's most recent research shows our clear impact on student achievement up until the pandemic."
That legislative momentum was real. In 2023, Montana became the 46th state to pass a law allowing charter schools to operate. The map of charter authorization had expanded dramatically since the movement's early days, and the political battles over whether to allow charters had largely been won in most states though debates about funding, facilities, and equity continued.
The Research Landscape: What Studies Are Finding
Behind the political story is a research story, and it is one that the charter sector has increasingly leaned on to make its case. The Thomas B. Fordham Institute, a think tank that has produced substantial research on charter schools, has commissioned and published a range of studies examining performance, competition effects, and outcomes for specific student populations.
One Fordham study from December 2023, titled The Education Competition Index, estimated how much competition the 125 largest U.S. school districts face for various student groups, and how that competitive pressure has changed over the past decade. The findings offered a window into how charter schools are reshaping the choices available to families and how districts are responding to that competition.
Another Fordham study, from May 2023, examined charter schools and English Learners in Texas, a state with a rapidly growing English Learner population. The study, by Deven Carlson of Oklahoma University, investigated the effects of charter schools on the achievement, attainment, and earnings of English Learners a population that research has sometimes found to be underserved in traditional public schools. The findings offered evidence about whether charter schools were doing a better job of educating this group than regular public schools.
A third Fordham study, from January 2024, looked at what researchers called "residentially mobile students" children who move frequently, often due to family instability, housing insecurity, or economic hardship. The study, titled New Home, Same School: Charters and residentially mobile students, asked whether enrolling in charter schools offered unique benefits to students who experience what researchers called "residential instability." The question matters because student mobility has been linked to lower academic achievement, and because charter schools' stable enrollment structures might offer a form of continuity that frequent moves otherwise disrupt.
These studies represent a broader pattern: as the charter sector has grown, researchers have increasingly tried to understand not just whether charter schools work, but for whom, under what conditions, and in comparison to what alternatives.
"I want to know that all families have a quality choice available to them, and that they have the data at hand to know which schools are advancing their children's learning and which are not."
Rick Cruz, National Alliance for Public Charter Schools Chair of the Board
Governance and the Question of Accountability
One of the defining features of charter schools is their governance structure. Unlike traditional public schools, which are overseen by elected school boards, charter schools are governed by nonprofit boards of directors. This gives them more autonomy in areas like curriculum, staffing, and scheduling but it also means they are accountable to a different set of stakeholders and a different set of expectations.
The Fordham Institute has also examined the question of authorizer quality. A study from March 2024, titled Do Authorizer Evaluations Predict the Success of New Charter Schools?, was written by Adam Kho of the University of Southern California, along with coauthors Shelby Leigh Smith (also USC) and Douglas Lee Lauen of the University of North Carolina. The study examined the extent to which authorizers' evaluations of new charter school applications predicted their subsequent success. The findings spoke to a practical question that policymakers and authorizers themselves have grappled with: if authorizers can identify strong applications, they might be able to screen out weaker proposals before they open and thereby improve the overall quality of the charter sector.
Rees herself had deep experience with governance questions. Before her tenure at the National Alliance for Public Charter Schools, she served as the first Deputy Under Secretary for Innovation and Improvement at the U.S. Department of Education under President George W. Bush. In that role, she worked on the passage of the No Child Left Behind Act and the D.C. Opportunity Scholarship, a federally funded voucher program. That background shaped how she thought about the relationship between autonomy and accountability a tension that sits at the heart of the charter model.
Challenges on the Horizon
The charter sector's growth has not come without headwinds. In her 2024 interview with Rick Hess, Rees acknowledged that the movement faced real challenges, even as she emphasized its momentum.
"The pandemic demonstrated the demand for greater flexibility in education," Rees said, according to the Education Week interview. But she also noted that pandemic learning loss had created new pressures, and that political polarization around education had made the environment more contentious. Education Savings Accounts programs that allow states to direct public funding directly to families for educational expenses represented another area of competition and debate, one that some charter advocates viewed as complementary and others viewed as a threat.
The political environment had grown more charged. After years of expanding the map of states that allowed charter schools, the movement had entered a phase where questions about funding equity, facilities access, and the demographic composition of charter enrollments had become harder to sidestep. Charter schools, by their nature, are schools of choice and choices are not equally available to all families. Transportation barriers, application deadlines, and information gaps can mean that the families who most need better options are least able to access them.
Rees's own departure at the end of 2023 marked the close of an era. She had led the National Alliance for Public Charter Schools for 11 years, through a period of substantial growth, political change, and research development. Her successor would inherit a sector that was larger, more politically visible, and more deeply examined than when she started.
What This Means for EducationGuide Readers
For readers researching education resources, learning guides, and the frameworks that shape how schools are designed and evaluated, the charter movement offers a case study in how autonomy, accountability, and innovation interact in practice. The movement has generated a substantial body of research not all of it flattering, not all of it conclusive that can help practitioners and policymakers think through what works, for whom, and under what conditions.
The studies commissioned by Fordham and cited by the National Alliance represent a serious effort to move beyond advocacy and into evidence. Whether readers are evaluating a charter school for their own family, designing a program that might learn from the charter model, or simply trying to understand the landscape of American public education, this body of research is worth engaging with directly.
What the charter movement has demonstrated, at minimum, is that there is appetite for something different inside the public school system and that when given the freedom to experiment, some operators can produce results worth studying. The harder questions, which the research is only beginning to answer, are about scale, equity, and sustainability.
Where to Read Further
For readers who want to go deeper, the National Alliance for Public Charter Schools maintains research and data resources at publiccharters.org, including summaries of recent studies and policy analysis. The Thomas B. Fordham Institute's research compilations are available at fordhaminstitute.org, covering topics from authorizer quality to outcomes for English Learners. And the full interview with Nina Rees, including her reflections on the movement's evolution and the challenges ahead, is available at Education Week.