The biggest cities in this country are getting even bigger.

That’s according to new Census Bureau data, showing that almost every major urban center gained population from 2023 to 2024.

Most big cities shrank early in the pandemic, when a lot of people opted for suburbs and rural areas with more open space.

Cities create a disproportionate share of economic growth in the U.S., said Esteban Moro, director of the urban networks lab at Northeastern University. He said nothing beats being around other people “in terms of job creation, opportunities, innovation.”

Moro said cities produce higher salaries, more startups, even more patents per capita. That’s why Gianpaolo Baiocchi, director of the urban democracy lab at New York University, is excited that more people are living in them.

“There was this talk a few years ago that cities were gonna die, and cities are back,” said Baiocchi.

Their growth was fueled in large part by immigration, which Baiocchi said helps with an aging urban workforce.

“It's keeping the population young, which means we can have a solvent social security system, we can have a solvent Medicare, these kinds of things,” said Baiocchi.

Of course, a booming urban population can lead to some growing pains.

“Yeah, I mean, there’s always two sides to it. I’m an economist,” said Hanna Scovill with the Metro Denver Economic Development Corporation.

She said while fast growth has helped ease a labor shortage, it’s exacerbated a housing one.

“What we saw in previous decades, we were growing too fast and we can't keep up with the pace of household formation,” said Scovill.

Perhaps the most dramatic example of the changing fortune of cities is New York. It lost more people, in absolute numbers, than any other during the first year of the pandemic. Then, last year, it gained more than any other.

“It helps significantly that New York City's growing again. That bolsters our tax base. It helps make sure that our fundamentals are strong,” said Scovill.

But, said Eli Dvorkin with the Center for an Urban Future, “Without tackling that affordability challenge with major housing construction, we're not going to be able to retain the folks that are moving to New York.”

Dvorkin said the urban economic engine only works when you’ve got the people to fuel it.