Opinion

Pre-K pretensions

Mayor de Blasio was beside himself Thursday, boasting about the launch of his pre-K expansion. He called it the fulfillment of a “dream” he and his wife had “for a long time.”

Whether it fulfills the dreams of city schoolkids, of course, remains to be seen. There’s ample cause to be skeptical.

“We talk constantly about the question of how do we move this school system, how do we fundamentally change it?” said the mayor. “And we know that full-day pre-K for every child is one of the most fundamental ways to shake the foundations.”

De Blasio bragged that “50,000-plus kids” are in pre-K this year, compared to about 20,000 last year, and called this a “huge step forward.”

Yet if pre-K is such a panacea, why does it seem to be doing so little good at so many schools where it already exists — for example, in PS 133, PS 15 and PS 140 in Manhattan and PS 328 in Brooklyn?

These four schools already offer pre-K, and yet not a single third-grader — not one — at any of them was able to pass the state’s 2014 English test.

Even more broadly, 90 percent of kids at 74 elementary schools with pre-K couldn’t pass math or English. At eight, only one in 20 passed math.

True, kids at some schools with pre-K do OK. But this may have more to do with the quality of the school than the existence of pre-K.

Fact is, studies are inconclusive about pre-K’s long-term effectiveness. And any meaningful findings about de Blasio’s expansion will not be known until long after he’s left office.

By then, of course, it will be too late for yet another generation of schoolchildren whose parents are now being told pre-K is the magic fix.