Integration now

New York City’s leaders are finally confronting one of the deepest shames of the nation’s largest school system: that students are clustered by race and socioeconomic background in a way that tends to exacerbate, rather than alleviate, inequality.

Mayor de Blasio, who for years has been too cautious to tackle the challenge, deserves credit for embracing a real integration plan in Brooklyn’s Community School District 15, on whose board he once served.

It may be the bolder rhetoric of Schools Chancellor Richard Carranza that dragged Hizzoner in the right direction; it may be the initiative of local leaders, including parents, principals and Councilman Brad Lander; it may be a public policy epiphany.

Whatever the motivation, we’ll take the belated awakening.

District 15, which includes a wide swath of central Brooklyn, educates a complex range of kids — from well-off, predominantly white kids in Park Slope, Boerum Hill and Carroll Gardens, to Asian and Latino immigrants and children of immigrants in Sunset Park, to underprivileged black and Latino residents of Red Hook housing projects.

The district’s elementary schools, which tend to serve their immediate neighborhoods, are not ethnically and socioeconomically diverse. Its middle schools, which could be — because choice, not district lines, determines who they serve — aren’t either, because 10 of the 11 screen entry, considering fifth graders’ test scores, attendance, grades and other factors before giving a kid a seat.

The approved diversity plan will remove those filters, moving to lottery-based admissions, with priority for low-income families, English Language Learners and students in temporary housing.

This is very good.

We fully understand that public-school parents, many of whom like the schools to which they send their sons and daughters, worry about re-sorting the applecart. It’s better to keep middle-class parents bought into the public school system than lose them to private schools or the suburbs.

But fear is no excuse for timidity. Mixing ought not wait until middle school; elementary schools where catchment zones allow separate-and-unequal educations are where the problem begins. Redraw them. And when community school districts lack internal diversity, desegregation efforts should cross those borders.

Studies show that when kids are clustered by background, disadvantaged youngsters get the short end of the stick. When kids are productively mixed, the chronically underserved benefit, without dragging down their peers.

But this is much about morality as it is about educational outcomes. We live together. We should learn together.