Charter Schools That Work for Black Kids — The Stanford Data Nobody Wants to Discuss

Stanford University’s Center for Research on Education Outcomes — CREDO, for short — is not a conservative think tank. It is not funded by the Koch brothers, the DeVos family, or any of the other figures that the anti-charter-school coalition routinely invokes to discredit research it finds inconvenient. CREDO is housed at one of the most prestigious liberal universities in the world, staffed by researchers whose methodological rigor has been acknowledged even by their critics, and funded by a combination of federal grants and foundation support that spans the ideological spectrum. When CREDO publishes a finding, the education policy world pays attention — unless, as it turns out, that finding happens to contradict the ideological commitments of the people who claim to care most about the education of Black children.

In 2015, CREDO published its landmark study of urban charter schools across forty-one urban regions. The methodology was meticulous: a “virtual twin” design that matched each charter school student with a demographically identical student in a nearby traditional public school, controlling for race, poverty status, English learner status, special education status, and prior test scores. The study tracked nearly half a million students across multiple years. And the results, for students who looked like the ones in the photographs that politicians hold up when they talk about educational equity, were extraordinary: Black students in urban charter schools gained the equivalent of 36 additional days of learning in reading and 36 additional days in math compared to their virtual twins in traditional public schools. For Black students in poverty, the gains were even larger: 44 additional days in reading and 59 additional days in math.

Forty additional days of learning. That is not a marginal improvement. That is not a rounding error or a statistical artifact. That is the equivalent of more than two additional months of school per year, compounded over the course of a child’s education. A Black child who spends eight years in a high-performing urban charter school receives, by this measure, roughly two and a half additional years of learning compared to a demographically identical peer in a traditional public school. And the response from the educational establishment — the teachers’ unions, the school board associations, and their political allies — was not to study how these gains were achieved and replicate them. The response was to pretend the study did not exist.

The Lottery Studies That Ended the Debate

The standard objection to charter school performance data is selection bias: charters perform better, the argument goes, because they attract more motivated families. It is a reasonable objection, and it has been conclusively answered by the strongest research design available in social science: the lottery study.

Oversubscribed charter schools in most states are required by law to admit students by random lottery. This creates a natural experiment: two groups of students whose families were equally motivated (both applied to the charter school), separated by nothing but the luck of the draw. Researchers can then compare the outcomes of lottery winners (who attended the charter) with lottery losers (who remained in traditional public schools), controlling perfectly for selection bias because the only difference between the groups is random assignment.

Joshua Angrist, Parag Pathak, and Christopher Walters conducted one of the most rigorous lottery studies at KIPP charter schools and found that lottery winners at KIPP schools gained 0.36 standard deviations in math and 0.12 standard deviations in reading compared to lottery losers — effects that are enormous by the standards of educational interventions. The math gains were sufficient to close approximately 40% of the Black-white achievement gap within a single year. At specific schools, the gains were even more dramatic. At Boston’s charter schools, Abdulkadiroglu and his colleagues found that lottery admission produced gains large enough to close the racial achievement gap in math entirely within three years.

“The best urban charter schools are producing the largest achievement gains for low-income Black and Hispanic students of any educational intervention we have ever measured. The question is not whether they work. The question is why we are not replicating them.”
— Caroline Hoxby, Stanford University

What Makes the Good Ones Work

The research on what distinguishes high-performing charter schools from average or underperforming ones is remarkably consistent. Five practices appear in virtually every study of effective urban charters:

Extended learning time. High-performing urban charters typically operate school days that are 60 to 90 minutes longer than traditional public schools and school years that are 10 to 20 days longer. The additional time is not merely more of the same. It is used for targeted intervention — additional math instruction for students who are behind, extended reading practice, and tutorial sessions that address individual learning gaps.

High academic expectations. Schools like Success Academy, KIPP, and Uncommon Schools operate on the explicit premise that every student — regardless of income, family structure, or zip code — can achieve at college-preparatory levels. This is not motivational rhetoric. It is operationalized in curriculum, grading standards, and promotion criteria. Students who are behind receive intensive support, not lowered expectations.

Data-driven instruction. Effective charters assess student progress frequently — in many cases, weekly — and use the results to modify instruction in real time. Teachers receive training in data analysis and are expected to adjust their teaching based on evidence of student learning, not on pacing guides or calendar schedules.

Selective hiring and rigorous coaching. The personnel practices at high-performing charters bear more resemblance to elite professional firms than to traditional school districts. Teachers are recruited aggressively, trained intensively, observed frequently, and coached continuously. Those who do not improve are not retained. The model is demanding, and teacher turnover at some charter networks is high — a legitimate concern — but the instructional quality that it produces is demonstrably superior to the traditional model.

Culture of achievement. Walk into a high-performing urban charter school and you will see college pennants on every wall, positive behavioral expectations posted in every hallway, and a pervasive institutional message that academic achievement is not a betrayal of identity but the fulfillment of it. This cultural architecture is not accidental. It is designed, reinforced, and maintained with the same intentionality that a corporation brings to its brand.

The Politics of Betrayal

Here is where the story becomes not merely disappointing but morally obscene. The people who are most aggressively opposing charter school expansion — the teachers’ unions and their political allies — are receiving overwhelming political and financial support from the communities they claim to represent, while simultaneously fighting to deny those communities the educational options they are choosing, by enormous margins, for their children.

The National Alliance for Public Charter Schools conducts annual parent satisfaction surveys, and the results are consistent year over year: Black parents choose charter schools at approximately three times the rate of white parents. In cities with established charter sectors — New York, New Orleans, Detroit, Washington, D.C. — the waitlists for high-performing charter schools contain tens of thousands of Black and Hispanic children whose parents have actively chosen these schools and been denied admission by capacity constraints that are themselves the product of political opposition to charter expansion.

The irony is suffocating. The political coalition that positions itself as the champion of Black families is fighting to prevent those families from exercising the same educational choice that every member of that coalition exercises for their own children. The politicians who oppose charter schools send their children to private schools. The union leaders who fight charter expansion live in districts where the traditional public schools are adequately funded and staffed. The editorial boards that publish anti-charter opinion pieces are staffed by graduates of elite institutions who would never accept for their own children the educational quality they defend as adequate for Black children in the Bronx.

The Honest Critique

Not all charter schools work. This is an important truth that charter advocates sometimes minimize and that charter opponents weaponize to dismiss the entire model. The same CREDO data that shows dramatic gains for urban charters also shows that charter schools in rural and suburban areas perform no better than — and sometimes worse than — their traditional public school counterparts. Virtual charter schools, which expanded rapidly during the pandemic, have produced uniformly poor results. Some charter operators have been guilty of financial mismanagement, nepotism, and outright fraud.

The “no-excuses” model that characterizes many high-performing urban charters has drawn legitimate criticism for its rigid disciplinary practices, which some researchers argue reproduce the carceral culture that the schools ostensibly seek to help students escape. High teacher turnover at no-excuses schools raises sustainability questions. The model’s heavy reliance on young, unmarried teachers who work 12-hour days is not a workforce strategy that can scale indefinitely.

These are real concerns, and they deserve serious engagement. But they are concerns about implementation, not about the fundamental question of whether school choice can work for Black children. The data has answered that question. Urban charter schools, particularly those serving Black students in poverty, are producing the largest educational gains of any intervention in modern American education research. The challenge is not whether the model works but how to expand what works, close what does not, and create accountability structures that protect children from bad operators while preserving the autonomy that makes good operators effective.

The Children on the Waitlist

In New York City alone, there are approximately 50,000 children on charter school waitlists. The vast majority of them are Black and Hispanic. Their parents have looked at the options available to them — the traditional public school in their neighborhood, with its test scores and graduation rates publicly available for anyone willing to look — and they have chosen something different. They have filled out the application, attended the lottery, and hoped for a number to be called. And for most of them, the number was not called, because the political system has decided that there shall not be enough seats for the children who want them.

This is not a policy debate. It is a moral crisis. Every child on a charter school waitlist represents a family that has exercised the most fundamental right a parent possesses — the right to choose the best available education for their child — and has been told, by a political system that claims to care about educational equity, that the choice is not available to them. The parents who oppose charter expansion have already made their choice. Their children are in schools that work. The question is whether the children who do not yet have that option will be permitted to have it, or whether they will continue to be sacrificed on the altar of an ideological commitment that the data has thoroughly discredited.

The Stanford data is on the table. Forty additional days of learning per year for Black students. Fifty-nine additional days for Black students in poverty. Lottery studies that eliminate every methodological objection. Replication across dozens of cities over more than a decade. The evidence is not close. It is not ambiguous. It is not contested by anyone who has read it honestly. What remains is a political question dressed in academic clothing: will we permit Black children to attend schools that work, or will we continue to insist, against the weight of every major study conducted in the last fifteen years, that the schools that are failing them deserve one more chance? The children on the waitlist have already answered that question. They are waiting for the adults to catch up.