If you were lucky enough to grow up in the New York City school system, you more likely than not came across the story of Claudia and Jamie Kincaid in the children’s classic The Mixed-Up Files of Mrs. Basil E. Frankweiler, in which the two young children, yearning to leave their self-described dull Connecticut suburb, make their way to New York City and hide out in the Met Museum. And if you were lucky enough to have grown up in New York, you didn’t have to imagine the wonder and awe the two children had in the museum after hours: you likely went on many a school trip there and mapped out how you would evade security guards. You know, just in case.

Well, nearly 60 years after E. L. Konigsburg wrote the book of two kids running towards the city and away from their suburb-living parents, there are increasing signs of the complete opposite occurring: parents are taking their kids out of the New York City school system, and out of New York City entirely, and heading for the ‘burbs, thanks to the increased cost of raising a child here. Families with young children are leaving New York City at more than twice the rate of households without them, and the public school system is shrinking as a result.

A decade ago, the city had over 1 million public school students, but this year it has 885,000, City Comptroller Mark Levine said in a social media post on X—and he expects another 150,000 fewer over the next decade. The drop has left 219 schools with fewer than 200 students each, he said, some too small to field a sports team. “This is not sustainable,” he wrote in the post, and the city will have to consolidate schools with sharply declining enrollment, Gothamist reported.

Levine said in a statement to Fortune that cost is part of the story. “Raising a family in New York City is increasingly difficult as the cost of living rises, and declining student enrollment is one troubling sign of that challenge,” he said. “Affordability is a major factor, but not the only one, and we need to better understand every driver of this trend to respond with viable, data-driven solutions.”

“Families with young kids are twice as likely to move out of the city than the rest of the population,” Emily Eisner, executive director of the Fiscal Policy Institute, told Fortune. “That’s because it’s really expensive to raise kids in the city these days.” Housing adds to the pressure as children get older. “There’s basically no options for families to find an affordable housing situation,” she said.

The cost of raising a kid

An FPI report from June 2024 found that New York City households with a child under 6 were 112% more likely to leave than those without. They made up 30% of out-migrants but 14% of the population. Among New Yorkers who left the state after the pandemic, 36% said they wanted better or more affordable housing, up from 16% before it. The report calls the outflow a policy failure and says it raises long-run fiscal and economic concerns.

It’s not just the Big Apple: the cost of raising a child has climbed nationwide. LendingTree puts the 18-year total at more than $300,000, with childcare the largest expense for families with children under 5. Care for an infant and a 4-year-old averages $28,190 a year nationwide, which would take a household income of $402,708 to stay within the federal 7% affordability benchmark.

For comparison, the average two-child household earns $145,656. Parents spend about 20% of their income on childcare, according to Care.com, and one in five spend more than $30,000 a year. In a BMO survey, 82% of parents said the cost of raising children has “gotten out of control.”

Housing leaves less room still. A buyer needs at least $211,970 in household income to afford a median-priced home in New York City, nearly three times the national figure, according to StreetEasy, though that is down $10,625 from a year earlier. Meanwhile, only 15% of city households earn $200,000 or more.

Declining birth rates

Also compounding the strain is the declining birth rate, as U.S. fertility fell to a record low in 2024, to below 1.6 children per woman. Births in 2025 ran about 24,000 below the 2024 total. In New York, the city had about 110,000 births in 2019 and fewer than 100,000 a year since 2020.

A new FPI report shows the people leaving New York are not the wealthiest, Fortune reported last month. In typical years, FPI found, the top 1% of earners leave at one-quarter the rate of everyone else. But of middle-income families, Eisner said, “I don’t think they migrate because of taxes. They migrate because of the high cost of living, which really is about childcare costs and housing costs.”

Cost is not the only explanation. A city Education Department survey found that 40% of families who left the school system moved out of the city, citing a better environment to raise kids, concerns about schools, and more housing space.

Eisner said pushing for universal free childcare and a larger housing supply, referencing policies like how Mayor Zohran Mamdani campaigned on making child care free for children from 6 weeks to 5 years old, will ease that decline in children in the city. “Those will play a significant role in bringing the cost of living down.”

After all, the kids need a reason to map out their hideout spots in the Met.

This story was originally featured on Fortune.com