(AP Photo/The Winchester Star, Ginger Perry)

It is hard, at first, to find anything wrong with the idea that some public schools should have the freedom to be a little different. This was the original pitch for charter schools, as think-tank scholars Richard Kahlenberg and Halley Potter recount in their recent book A Smarter Charter.

“Schools were meant to be laboratories for experimentation from which the traditional public schools could learn,” Kahlenberg told the Post’s Valerie Strauss last week.

[Q&A with Richard Kahlenberg and Halley Potter]

President Obama has lavished praise on charters for this same reason, calling them “incubators of innovation in neighborhoods across our country.” His administration has provided more in charter school grants than any other.

It’s true that the charter movement has a sunny side. KIPP schools, for instance, mostly serve low-income and minority students, putting them through extra-long school days and imposing strict rules on their behavior. Many KIPP schools have accomplished what their public school counterparts couldn’t: yanking up test scores for kids on the wrong side of the achievement gap.

But for every successful school, there have also been failures. The research is mixed on the performance of charter schools, and it’s a mistake to believe that different is necessarily better. The question then becomes one of equity: Who gets to attend the good charter schools?

Setting aside the drama between charters and teachers unions, or complaints that charter schools lead to the privatization of public education, there has been the persistent critique that charters increase inequality by plucking advantaged students out of traditional public schools.

The most recent cautionary tale comes from North Carolina, where professors at Duke have traced a troubling trend of resegregation since the first charters opened in 1997. They contend that North Carolina’s charter schools have become a way for white parents to secede from the public school system, as they once did to escape racial integration orders.

“They appear pretty clearly to be a way for white students to get out of more racially integrated schools,” said economics professor Helen Ladd, one of the authors of the draft report released Monday.

Charter schools in North Carolina tend to be either overwhelmingly black or overwhelmingly white—in contrast to traditional public schools, which are more evenly mixed. Compare these charts from the report:


The bottom chart shows students that attend North Carolina’s regular public schools. There is a healthy variety of schools with different racial makeups. Only about 30 percent of students attend schools that are highly segregated, meaning schools that are more than 80 percent or less than 20 percent white.

The top chart shows students at North Carolina’s charter schools. More than two thirds attend schools that are highly segregated. You can see on the chart because the histogram has two humps, one at each racial extreme.

The charts also show how racial makeups have shifted over time. By 2014, a fifth of charter schools were overwhelmingly — more than 90 percent — white. In 1998, less than 10 percent of charters were that way.

Parental preferences are part of the problem. The charter school admissions process is itself race-blind: Schools that are too popular conduct lotteries between their applicants. But if a school isn’t white enough, white parents simply won’t apply.

In previous research, Ladd discovered that white North Carolina parents prefer schools that are less than 20 percent black. This makes it hard to have racially balanced charter schools in a state where more than a quarter of schoolchildren are black.

“Even though black parents might prefer racially balanced schools, the fact that white parents prefer schools with far lower proportions of black students sets up a tipping point,” the authors write. “Once a school becomes ‘too black,’ it becomes almost all black as white parents avoid it.”

Looking at students in grades 4-8, the researchers found that the regular public school population in North Carolina has become less white over the past 15 years (from 64.1 percent white to 53 percent white), while the charter school population has grown more white (from 58.5 percent white to 62.2 percent white).

Not only that, but the kids choosing charter schools these days also seem to be more able. The researchers examined how students had been scoring on standardized tests before they entered charter school. It used to be that kids with below average test scores applied to charter schools. But in recent years, the kids going into charter schools tend to have above-average test scores.

The researchers argue that this changing mix of students explains much of the test score gains among North Carolina’s charter schools. By their calculations, the schools haven’t gotten that much better at teaching students — but they have gotten better at attracting more able students.

In 2010, North Carolina received a $400 million Race to the Top grant from the Obama administration. As part of its application, it promised to eliminated the cap on charter schools, which had been stuck at 100. Now there has been a flood of charter schools seeking to open in North Carolina, and the researchers warn that the segregation problem might only get worse.

One problem is that disadvantaged students have less of a chance to attend a charter school. First, they or their parents have to be plugged in enough to know which are the good charter schools and motivated enough to apply. Then, they need to have the resources to actually attend the charter, because unlike regular public schools, charter schools in North Carolina do not have to offer transportation or lunch to students. For poor students who rely on school buses and free meal programs, the costs associated with attending a charter school may discourage them from the opportunity.

By contrast, affluent families might not think twice about driving their children to attend the high-achieving charter across town instead of a low-achieving neighborhood school. In this manner, even charter schools without explicit fees or admissions requirements may tilt toward inequality.

Ladd said that she would like to see charter schools be required to provide services on a par with what public schools offer. This would be a step toward making them more accessible. The board that oversees charter schools might also be more careful about approving new ones. Schools that plan to open in white or affluent neighborhoods are unlikely to attract anyone but white and affluent students.

State officials might be coming around to these ideas. Already last year, North Carolina rejected 60 of 71 applications for new charter schools. Some complained that applications were getting dinged for not having adequate busing and meal plans, though the charter school board denied this.

Similar problems have plagued other places. In December, the ACLU and the Community Legal Aid Society filed a complaint claiming that Delaware’s charter schools were re-segregating students. Top charter schools were disproportionately white, they say, in part because Delaware allows them to impose admissions requirements on their students.

Other states have had the opposite problem. For a long time, Tennessee limited its charter schools to serving low-income students, meaning that most have been located in neighborhoods with concentrated poverty. When that rule was lifted in 2011, Nashville’s school board began seeing proposals for charter schools targeting affluent, white students. The board soon began requiring that new charter schools have diversity plans to make sure they were not all-white or all-minority.

As America’s neighborhoods become increasingly segregated, it will take conscious effort to prevent public schools from also becoming more segregated, whether by race or by class or by disability. In the South, there were once private “segregation academies” for white students to avoid integrated schools. Without planning for diversity, North Carolina’s charter schools are at risk of resurrecting that legacy.