New tax data reveal a steep population loss in 2020, toward the start of the pandemic. The exodus was temporary, but how much of its effects could be permanent?When roughly 300,000 New York City residents left during the early part of the pandemic, officials described the exodus as a once-in-a-century shock to the city’s population.Now, new data from the Internal Revenue Service shows that the residents who moved to other states by the time they filed their 2019 taxes collectively reported $21 billion in total income, substantially more than those who departed in any prior year on record. The IRS said the data captured filings received in 2020 and as late as July 2021.Many new or returning residents have since moved in. But the total income of those who had initially left was double the average amount of those who had departed over the previous decade, a potential loss that could have long-term effects on a city that relies heavily on its wealthiest residents to support schools, law enforcement and other public services.The sheer number of people who left in such a short period raises uncertainty about New York City’s competitiveness and economic stability. The top 1 percent of earners, who make more than $804,000 a year, contributed 41 percent of the city’s personal income taxes in 2019.About one-third of the people who left moved from Manhattan, and had an average income of $214,300. No other large American county had a similar exodus of wealth.Early in the pandemic, Sam Williamson, 51, a white-collar defense lawyer living on the Upper West Side of Manhattan, first relocated to Utah, then to Long Island. After a return to the city, he and his family permanently moved to Miami last year when his law firm opened an office there.“I love New York City, but it’s been a challenging time,” Mr. Williamson said. “I didn’t feel like the city handled the pandemic very well.”The average income of city residents who moved out of state was 24 percent higher than of those who moved the year prior, according to a New York Times analysis of federal tax returns that were due in 2020. It was the biggest one-year income increase among people who left the city for other states in at least a decade.The tax data is in line with the most recent Census Bureau estimates, which showed that in the first year of the pandemic, the number of New York City residents who left was more than triple the typical annual outflow before the pandemic. International immigration, a key source of growth in New York, plummeted to one-fourth the level prepandemic. And the death rate surged, as approximately 17,000 more residents died than in a typical year.All of this led to a loss of about 337,000 people in New York City between April 2020 and June 2021, according to census estimates, a startling drop after the city’s population reached 8.8 million residents, a record high, in early 2020.New York City’s official demographers say that the pandemic was a blip in the city’s long-term population growth and that migration trends have returned to prepandemic levels, pointing to indicators like change-of-address requests and soaring rents that suggest people are flooding back.But, they said, it is too soon to conclude when the population that was lost will be completely replaced.And other indicators suggest flight from the city may be continuing. Public school enrollment this year is down 6.4 percent compared with before the pandemic, according to New York City Department of Education data, and private school enrollment decreased by 3 percent, according to state data, potentially signaling a reduction in the number of families that could hurt the city’s ability to foster a diverse work force.“All of these are underlying trends that are concerning,” said Andrew Rein, president of the Citizens Budget Commission, a nonpartisan fiscal watchdog. “We don’t know what this means permanently, but things have shifted in a way that should give anybody looking at this some serious pause.”In the years before 2019, the people who left and the people who stayed in New York City had similar average incomes, the IRS data showed. But during the pandemic, the residents who moved had average incomes that were 28 percent higher than the residents who stayed.Still, New York City collected more tax revenue in both 2020 and 2021 than in 2019, thanks in part to at least $16 billion in federal pandemic aid.The outlook for this year has become much less certain as the stock market has plummeted in recent months and certain forms of federal aid, like stimulus checks and expanded unemployment benefits, have ended.The city’s Independent Budget Office said it was not possible to calculate the tax revenue lost from the people who had moved because some of them could be working remotely for New York-based companies and paying city income tax. In the long term, the office said, their tax status could become a major policy issue as states fight for their share of taxes from remote workers.Sophia and Charlie Blackett relocated last year to Rowayton, Conn., from Brooklyn, partly because both of their jobs in tech allowed them to permanently work from home. Ms. Blackett, 27, had previously considered raising children in the city, but the confinement of the pandemic shifted her thinking.“I used to thrive on the hustle and bustle,” she said. Now, she said, “I think about waking up in my bed in an apartment, and I just feel a little bit anxious.”The issue has become a talking point in the governor’s race. Gov. Kathy Hochul, a moderate Democrat, said earlier this year that the steep population drop in New York State, driven by the city losses, was “an alarm bell that cannot be ignored.” Representative Tom Suozzi of Long Island, a centrist challenging her in this month’s primary, has blamed the exodus on crime, high taxes and an unaffordable cost of living.Gergana Ivanova, 28, a clothing designer and social media influencer, said her decision to move to Miami was less about taxes. The pandemic made the downsides of living in New York City more noticeable, she said, including the lack of space in her tiny Queens apartment and the trash piling up on the sidewalks. She felt less safe walking around when the streets were emptier.“It didn’t feel happy and positive like it used to,” she said.Gergana Ivanova at Margaret Pace Park in Miami, where she moved from Queens.Scott McIntyre for The New York TimesUrban planners and economists have long debated the extent to which policymakers should be concerned about the outflow of New Yorkers to other states. Some see it as a positive sign of mobility for people who start their careers in New York, making way for new arrivals to inject vibrancy into neighborhoods.In a new report published Thursday, the Department of City Planning said federal immigration levels and change-of-address data from the Postal Service show that New York City’s population trends likely returned to prepandemic levels by the second half of 2021. And deaths from Covid-19 are significantly lower than early in the pandemic.Since the 1950s, New York City has had a net loss of residents to other states, but the population still grew because the number of immigrants and new births surpassed the number of people who moved away.The pandemic spurred a flight to many of the same suburbs that have long attracted New Yorkers seeking more space, including Connecticut’s Fairfield County and New Jersey’s Bergen and Essex Counties. But it also triggered residents to leave for more far-flung destinations, including Hawaii, the Florida Keys and ski towns in Colorado, Utah and Wyoming.Charlie and Sophia Blackett moved to Rowayton, Conn., from Brooklyn.Anthony Nazario for The New York TimesThe exodus to Florida was especially robust, and not just for the retiree crowd. In 2020, New York City had a net loss of nearly 21,000 residents to Florida, IRS data showed, almost double the average annual net loss from before the pandemic.The pandemic accelerated the relocation of several New York-based financial firms to new offices or headquarters in Florida. Many of them have landed in Palm Beach, Fla., including the hedge fund Elliott Management, whose co-chief executive, Jonathan Pollock, is now a full-time Florida resident, according to records obtained by The New York Times.The Manhattan residents who moved to Palm Beach County had an average income of $728,351, IRS data showed.Many New Yorkers also moved because they lost their jobs in the industries hardest hit by the pandemic. In New York City, the unemployment rate is almost double the nation’s, in part because the city still has at least 61,000 fewer leisure and hospitality jobs than before the pandemic, according to the most recent jobs report.Zak Jacoby was the general manager of a bar on the Lower East Side when the pandemic hit. Throughout 2020, his employment status fluctuated with the city’s changing indoor dining rules, a stressful period that put him on and off unemployment benefits.Mr. Jacoby, 37, flew to Miami in January 2021 to see a friend — and decided to stay permanently after getting a job offer at a local restaurant group. If there was another virus surge, he said, the state would be less likely to shut down businesses, giving him more job security.“My mind-set was, Florida’s more lenient on Covid, and there’s going to be less regulation,” he said.During his first six months in office, Mayor Eric Adams visited cities like Miami and Los Angeles as part of what he said were efforts to lure businesses and residents back to New York.Jonathan Koplovitz, 53, an executive at an automotive engineering and design start-up, is among the residents who came back.As the virus began sweeping through New York, Mr. Koplovitz and his family moved from their apartment in Manhattan’s Chelsea neighborhood to Aspen, Colo., the upscale ski resort town. Expecting to stay permanently, they bought a home about a mile from the ski lifts, where his two teenage sons finished the rest of the school year with virtual classes.But on a trip back to New York, he found the city to be far more vibrant than the darkest days of the pandemic. Once in-person schooling resumed in fall 2020, the family decided to return.“There’s no place like New York,” Mr. Koplovitz said. More