Eight and a half million stories, and counting, in the naked city. Photo: Mitchell Funk

Midafternoon on a weekday, and I’ve come to a midtown street corner to conduct an experiment in standing still. It’s virtually impossible. Two men in suits march toward me and diverge, including me for a moment in their conversation about insurance as they each knock one of my elbows on their way by. A child ricochets off my knee as his family parts around me and regroups on the other side. In one minute, I am jostled nine times.

There are a lot of opportunities to experience New York’s human abundance: a sunny day on the Brooklyn Bridge walkway, a rush-hour 6-train platform, a kindergarten class in the South Bronx, Flatbush Avenue gridlock, Flushing Main Street, the High Line. The city now has more residents than ever before — 8,550,405 as of a year ago, according to the federal Census Bureau — plus the more than 600,000 commuters who flow in and out each day and the 58 million out of-towners who visit each year. Those numbers are probably already out of date, since they’ve been rising for years, and projections suggest that by 2040, the masses will be nine million strong. In the last decade, New York has acquired record numbers of homeless people, artists, immigrants, and subway riders. We produce more garbage and patronize more restaurants. More visitors are jamming ever-larger museums.

How many New Yorkers can New York take? Going to work in the morning already feels like being channeled from cattle chute to holding pen; can another half-million humans really move to the center of the car? And what happens when the population hits the next round number? Does it just keep going? Do we plant new groves of super-tall towers in Queens, or start to hobble the construction industry? The prospect of ever-greater multitudes brings visions of round-the-clock traffic jams and buckling subways, regular brownouts and overwhelmed sewage plants, hour-long waits for pizza delivery and low blocks razed to make way for high-rise clones. Pessimists might find dismal comfort in the thought that no sane person would want to live in such a hyperpopulous city, so sooner or later it will start emptying out.

But the future won’t be apocalyptically simple. Despite the Dantesque choke points and the upward thrust of rents, the truth is that New York can handily absorb its crowds. More people still move out every year than are replaced by new arrivals from other parts of the country. School enrollment is dropping, not rising, as the demographic juggernaut of millennial parents steams by, leaving a baby bust in its wake. Traffic, believe it or not, is flat citywide. And it’s still not all that hard to find a quiet public place in the middle of this heaving snarl of humanity. (I’m not telling where mine are.) Even now, large areas like the South Bronx still haven’t clawed back the losses of decades ago. Brooklyn — booming, gentrifying, Manhattanizing, brand-exporting Brooklyn — remains more thinly settled than it was in 1950. “We’re going back and filling up places that were depopulated,” says Joseph Salvo, chief demographer at the Department of City Planning. “They already have the capacity, and the infrastructure is already there.” (It’s true that those future dispersed armies won’t just stay in their quiet boroughs; they’ll go to work, on those same groaning subways, but jobs move, too, and new populations don’t always follow the same trajectories.)

In global terms, our growth is anemic, a pale echo of the overwhelming urbanization sweeping across the world. More than half of the Earth’s population is now jammed into cities. Lagos, Nigeria, takes in more new arrivals every month than we do in a year. And although our population density of 27,000 people per square mile may seem impressive in American terms, it doesn’t even qualify for a berth in the world’s top 200. New York is not expanding into a crisis; compared to the ballooning megalopoli of the developing world, it’s merely thickening a bit around the edges.

Still, New York’s superpower is its magnetism. It makes people all over the world — we who live here, the millions who visit, the millions more who know its folkways from movies and television shows and photographs — feel as though they own a piece. True, we also encourage the illusion that our city harbors an inner circle of true New Yorkers, that only those with a birthright or long experience really understand its soul. But live here long enough, get to know enough people, and you find that few of them were born and grew up in the five boroughs, and many of them keep vaguely alluding to their wish to move away. From the beginning, people have flowed in and sprayed out at a furious rate. Yes, the population level rises a bit when we live longer and dips when we have fewer babies, but the real spikes come from the mechanism that has been energizing New York for 400 years. Immigrants gush in, settle, and disperse. Young people arrive, have children, and clear out. The soul of the city is churn.

And so, despite nativists’ recurring desire to shut the gates to the city, or to specific neighborhoods, New York has continued to grow — usually vertiginously, more incrementally now — and adapt to its new constituents. The sole decadelong blip in that trend, the 1970s, inflicted unforgettable urban trauma. Today, the same concentrations of insanity and opportunity attract people and chase them away. It’s far too expensive for artists to live in New York these days — but they keep coming, since even though nobody can afford to live here, it’s still the only place to live. Crowds are not a by-product of the city’s success; they are a measure of it.

As anyone who has ever played SimCity knows, growth is an urban planner’s drug. It boosts the economy and stimulates the tax base, making a city taller, busier, shinier, and faster. (Too much, ingested too quickly, causes the body politic to fall apart, but we’re a long way from that.) And to some extent, steering the city toward a population of nine million draws on gamelike management skills. The de Blasio administration, like the Bloomberg administration before it, keeps trying to herd new populations toward transportation nodes. We’re seeing the effects on the skyline: a new wedge of skyscrapers in downtown Brooklyn, phalanxes of waterfront condos, the great upwelling of Hudson Yards. (Much of the city remains horizontal, an expanse of single-family houses and stumpy apartment buildings, its scale enshrined by zoning and desire.)

Some New Yorkers resent the policies that produced these new cityscapes, seeing in them an implicit invitation to jam streets and subways, or to displace longtime residents. But New York should neither fear nor count on perpetual growth, because no sooner do we extrapolate from current trends, than those trends change course. In recent years, the patterns and proportions have shifted in ways that alter the city’s feel. Around 2000, half of new arrivals began their journeys abroad: Bangladeshis congregated in Coney Island, Chinese in Sunset Park, Mexicans fanned out across the boroughs. Today, immigrants continue to arrive at a more or less constant rate, but now they are being swamped by arrivals from other parts of the U.S., mostly students or childless young college grads, living alone or with roommates.

The kids are transforming the city — for now. They swirl into immigrant neighborhoods, mixing in with newcomers of other languages and religions. They make landlords salivate, drive up rents, and contribute to the gentrification wars. But they also power the creative and tech sectors, pay taxes, and buy things — without straining hospitals or filling classrooms. They blaze new commuter cowpaths, between Astoria and Dumbo, say, or from Manhattan out to Jersey City. They don’t just make their money here — they bring it with them. Immigrants send remittances home; the Girls generation receives them. In effect, parents all over the country subsidize New York’s creative industries, educating children who bring their skills and ambition here, then bridging the gap between an editorial assistant’s salary and the rent on a share in Bushwick. They live like they love cities, and maybe even this one in particular. It’s a good deal for New York.

The big unknown is how long any of these patterns will endure. Europe’s migrants might could ricochet toward the East Coast, a Trump presidency could drastically choke off immigration, Brexit may usher in a global economic ice age. If the market for freshly minted coders tanked, it would take Brooklyn’s real estate market with it. “One reason we’re growing now is opportunity,” says Salvo. “We haven’t seen this level of job growth since we’ve been recording it. But the next recession, or the next immigration law, could change that.” He’s seen it happen. In 2008, when the economy fell apart, Salvo realized he needed to extend his timeline for hitting the nine-million target by ten years, from 2030 to 2040.

Scrutinizing new arrivals only tells you half the story of how New York is changing; those who move away leave their mark, too. Maybe everyone who has ever rented an apartment barely big enough for a toaster and a desk lamp has dreamed of clearing out. Writing in Citylab recently, the urban guru Richard Florida reacted in alarm to a real-estate company report showing that the poor and the young were fleeing the entire metropolitan area (including the New Jersey suburbs) in higher than expected numbers. “The affluent and the talented are flooding into superstar cities and tech hubs, creating a vicious competition for space that is pushing out the young, the less advantaged, and those who do not own homes, reinforcing the deepening class divides in our cities,” Florida wrote. That makes it seem as if those who flood in belong to a fundamentally different group from those who ebb out, but that’s not necessarily true. The “talented” coming in and the “young” going out are often the same people. The cost of urban life often drives out those who’ve spent years patching together an existence rather than a career.

One imponderable is whether millennials will age differently than their parents and grandparents did. Will they continue to drive less, bike more, and settle ethnically mixed urban neighborhoods once age and parenthood kick in? Or will the lure of the suburban backyard and the highly ranked school district eventually siphon off youngish tech workers en masse?

The unpredictability of a real city makes it challenging to plan for growth — to build new schools where they’re needed, for example. School enrollment is expected to rise in the Bronx, spike in Queens, slip in Brooklyn, tumble in Manhattan, and stay pretty much flat in Staten Island. Those trends mask a lot of hyperlocal quirks. A neighborhood that becomes a magnet for large immigrant families may have a school that’s bursting at the seams. The next Zip Code over might fill with Orthodox Jews, who send their children to religious, not public, schools. Tangling the puzzle even more is the fact that responding to growth also creates more of it. The longer families last in the city, the more seats the school system will need. At the same time, the stronger the schools, the more young families will find the city a congenial place to bring up kids … and the more crowded they will make it.

But imagine that some future mayoral administration could wean itself from its need for another growth fix. Say it decided that the city was big enough — what would it actually do? Place a moratorium on new construction, and risk sending the economy into a death spiral? Build a Trumpian wall? Betray its identity and put up an Unwelcome! billboard at the entrance to the Lincoln Tunnel, with a sign pointing toward Pittsburgh?

The truth is, there is no acceptable way to turn back those who want to live in a great city. The Bay Area’s restrictive zoning and surreal prices didn’t prevent it from attracting 90,000 more people since 2014. Some Midwestern cities have done a good job of eroding their populations by deploying a mix of deindustrialization, meth addiction, poverty, illness, and crime. But even failure is no guarantee of shrinkage. Those cities are urban Edens compared to the world’s fastest-growing megalopoli, which boast threadbare electrical systems, open-air sewage canals, and epic traffic jams.

Those who like the city just the way it is (or the way they think it was) always have some group or other that they want to keep out. Usually it’s some flavor of foreigner that threatens the status quo; today it’s supposedly pampered domestic millennials. But cities don’t operate on a first come, first served basis. What gives people a right to live in New York is the fact that they’re here, not their disembarkation date.