New York City’s public school enrollment has experienced a 2% decline this year, a trend that’s expected to persist. However, our political leaders are likely to respond with denial rather than action.

The decrease in student numbers within the Department of Education reflects a broader pattern driven by a declining birthrate and a steady departure of young families from the city. The recent migrant crisis temporarily masked this ongoing decline.

The sensible solution would be to adjust the scale of city schools accordingly. This would involve closing some school buildings and reducing staff numbers, including both teachers and administrators. Such measures could also provide an opportunity to phase out dilapidated facilities and enhance the quality of the teaching workforce.

However, the United Federation of Teachers (UFT) is apprehensive about these changes. A reduction in teaching positions would decrease their dues income and alter the power dynamics within the union, as retirees would have a greater influence in electing UFT leadership.

In response, the UFT has advocated for state mandates on smaller class sizes, which would compel the city to hire more teachers despite a shrinking student body. Additionally, with pre-K staff also part of the union, the UFT is eyeing the mayor-elect’s universal day care plans as a potential opportunity.

But it won’t be enough: The number of new students registering for school this summer was down 7% from the year before.

Parents are giving up on the city, and on the DOE: Only charter public schools, which operate outside the bureaucracy and mostly without UFT members — and so reliably actually educate their students — are resisting the decline.

At some point, every other interest that depends on city spending is going to notice how the DOE consumes an ever-larger share of the pie — it’s already more than a third of the city budget! — to serve an ever-smaller population.

Even a proud Democratic Socialist may start asking some tough questions.

Mayor-elect Zohran Mandani would be wise to use this reckoning to upgrade the public schools: If they can’t deliver value, families need to pay out of pocket for their kids to learn — the reverse of making the city more affordable.

If he lets the vested interests continue to milk the system dry, he’s going to run out of taxpayers.