In New York City, a surprising number of elementary school students opt-out of their neighborhood schools — but who travels, where they go, and who stays put, is tangled in race, class, and gentrification.

Those are some of the findings in a report released Wednesday by the Center for New York City Affairs at the New School. For the first time, researchers used a decade of student- and school-level enrollment data to track where kindergartners go to school, and where they live.

The report challenges the argument that city schools are segregated because neighborhoods are. In fact, 40 percent of kindergartners last year did not go to the school they are zoned for, instead attending charter schools, gifted programs, other special programs, or just regular schools that aren’t assigned to their address. That’s up from 28 percent in the 2007-08 school year.

But the findings show that families experience that “explosion” of choice differently depending on whether they are black or white, middle-class or affluent.

Here’s what we learned from the report, “The Paradox of Choice: How school choice divides New York City elementary schools.”

The growth of choice might have made some schools more segregated.

One idea behind letting families choose schools beyond their neighborhood is that they might wind up sending their children to school with classmates from different backgrounds. Research is clear on the benefits of doing so: For the most part, all students benefit from being in classrooms that are economically and academically integrated.

But if New York City students were to stay put, schools would actually be slightly less segregated than they are today by some measures, according to the report. About 6,300 more kindergarten students would attend schools that are close to the citywide average in terms of student poverty. About 2,300 students would attend schools that the education department considers racially representative, meaning between 50 percent and 90 percent of students are black or Hispanic. (Some have criticized that metric, saying that schools within those ranges should still be considered segregated.)

The numbers are based on a big assumption: that parents would continue to live in the same neighborhoods and stay within the public school system if they lacked choice. In practice, not allowing school choice could drive some families, especially affluent ones, to choose to live elsewhere or enroll in private schools.

The theoretical impact of removing school choice is relatively small, compared to the 75,000 kindergarten students who started school in New York City last year. Still, the data shows that choice hardly adds diversity in a city where schools are deeply segregated.

“If you thought school choice was going to make things more integrated, think again,” said Clara Hemphill, one of the report’s authors. “It doesn’t make things more integrated. And in some neighborhoods, it makes things more segregated.”

Families aren’t just heading to the new school next door.

Nearly half of city schools admitted out-of zone students last year, compared with only 28 percent in 2007-08, according to the report. Much of that growth has come from an expansion of charter schools.

Many of the new school options that have emerged in the last decade have aimed to offer families choices within their neighborhoods. The city has added gifted programs in most districts and created unzoned schools that draw children from across their swath of the city. In the case of charter schools, new choices sometimes are located even within the school buildings that house zoned schools that children would otherwise attend.

But many families are traveling far afield to take advantage of choice. A third of kindergarten students who traveled did so across district lines, according to the report — often into higher-income neighborhoods, from Harlem to the Upper West Side; from Crown Heights to Fort Greene; or from southeast Queens to Bayside.

Families in gentrifying neighborhoods travel most – and, now, so do black students.

Recent studies have found that school choice increases the likelihood that a mostly black or Hispanic neighborhood would see an influx of wealthier residents — who can now move in with the knowledge that they don’t have to enroll in local schools.

Those findings are born out in the New York City report. Living in a gentrifying neighborhood was found to be “the largest predictor of choice,” with 60 percent of families choosing to send their kindergartner elsewhere.

Regardless of where they lived, black students were also among the most likely to travel outside their zone. About a third of all students who opt out of their local school are black, with 59 percent of black students choosing a different school — more than any other racial or ethnic group, and over 50 percent more often than they did a decade ago.

“Families of color are bearing this extraordinary burden of having to go through school choice and making the trek every morning to just find a better school,” said Nicole Mader, one of the report’s authors.  

The most affluent and poorest families tend to stay put.

The researchers found that some students are far less likely to opt out of their neighborhood school — and that their reasons likely differ.

In high income areas, more families stay in their zoned school — one that families might be spending heavily to be assigned to. “Zones provide families of means with exclusive access to the schools they like, while choice allows them to flee the ones they don’t,” the report says.

But students who qualify for free lunch — a common measure of family poverty — were 80 percent less likely to travel outside their school zone. Students who are still learning English as a new language were 73 percent less likely to leave. The report notes that “may reflect the high costs of choice to families,” which requires them to navigate opaque admissions systems without the advantages of social networks that more wealthy families can tap into.

The choices families make maps to who they are and where they live.

One argument in support of school choice is that it allows families to enroll in higher performing schools. The report found that often happens in New York City: Students tended to travel to schools where test scores are higher.

But even among families who choose, there were clear differences in the types of schools that parents prefered depending on where they live and their race.

White parents who live in gentrifying neighborhoods headed to schools that were less diverse. They enrolled their children in schools with 19 percent fewer poor students and 14 percent fewer black and Hispanic students than their zoned option. Black, Hispanic, and Asian families in gentrifying neighborhoods tend to enroll their children in schools with the same total proportion of students of color — but where students are less poor.

For black students, opting out often means enrolling in a charter school. The report found that 30 percent of black kindergarteners attended a charter school — compared with 13 percent of all students. White and Asian students, meanwhile, were more likely to travel to a gifted program.