Overall, 2021 will go down as the year with the slowest population growth in US history.
New census data shows why: Both components of growth — gains from immigration, and the number of births in excess of the number of deaths — have fallen sharply in recent years. In 2021, the rate of population growth fell to an unprecedented 0.1 percent.
Yet within these sluggish figures a new pattern is emerging. Immigration, even at reduced levels, is for the first time making up a majority of population growth.
In part this is because Americans are dying at higher rates and having fewer babies, trends accelerated during the coronavirus pandemic. But it’s also because there are signs that immigration is picking up again.
Even after four years of stringent controls on immigration imposed under former President Donald J. Trump, the overall share of Americans born in other countries is not only rising, but coming close to levels last seen in the late 19th century.
The numbers are not nearly what they once were. The latest report, from the Census Bureau’s population estimates program, showed a net gain of 244,000 new residents from immigration in 2021 — a far cry from the middle of the previous decade, when the bureau regularly attributed annual gains of one million or more to immigration .
Yet that drop-off pales in comparison to the slowdown in what demographers call “natural increase,” the excess of births over deaths. In 2021, that figure was 148,000, or one-tenth the gain that was normal a decade ago, and smaller than international migration for the first time ever.
As of December, immigrants represented 14.1 percent of the US population, matching the peak of the decades-long immigration boom that began in the 1960s and approaching the record 14.8 percent seen in 1890, shortly before large numbers of Europeans began disembarking from vessels at Ellis Island.
The foreign-born population is increasingly concentrated among middle-age groups, with a large number of immigrants having lived in the United States for many years. About 1 in 5 Americans between the ages of 40 and 64 was born overseas. And two-thirds of foreign-born residents have been in the country more than a decade, the census data shows.
In that respect, the country’s demographics reflect the long-term effects of the huge levels of immigration it experienced during the 1970s and 1980s.
“We get so used to being around people who have been here for decades and navigate American society seamlessly that we almost forget they’re immigrants,” said Tomás Jiménez, a Stanford professor who researches immigration and assimilation.
The recent slowdown in immigration was an apparent result not only of the tougher immigration policies, but also measures taken in response to the Covid-19 health crisis. In the early months of 2020, the government sealed the borders with Mexico and Canada and limited international entries by air. The closure of US consular offices around the globe derailed visa processing.
But the data suggests that tougher restrictions on the border may not have been the biggest factor in the slowdown. Many immigrants decided to leave the country. During the first years of Mr. Trump’s administration, the number of immigrants coming into the country held steady, while the number leaving increased, figures show.
Some data suggests that the pace of immigration has picked up lately. US Customs and Border Protection reported a surge in enforcement activity last year, and the Census Bureau’s monthly employment survey also detected an uptick in foreign-born respondents in late 2021.
The economic and political circumstances that compel people to leave their home countries have persisted, and demand for foreign workers of all skill levels remains brisk.
The newcomers since President Biden took office come from all over the globe, as the government has lifted the cap on refugees, welcomed thousands of families seeking asylum on the southwestern border and reopened the door to foreign workers on temporary visas.
Among them is Jeff Quetho, 28, of Haiti, who crossed the border with his 3-year-old son, hoping to build a more stable life; Param Kulkarni, 34, an Indian scientist who specializes in mental health technology and artificial intelligence, who recently settled in New York; and Feroza Darabi, 22, of Afghanistan, who arrived in Phoenix with her 13-year-old nephew, Ali.
“I am happy to be somewhere safe,” Ms. Darabi said recently during a break from an English class for refugees at Friendly House in Glendale, Az.
Ms. Darabi hopes she will be joined one day soon by family members who were unable to scramble onto the plane she and her nephew boarded out of Kabul. “What I want most now is to have my family next to me,” she said.
If immigration returns to even its relatively modest prepandemic pace, it is possible the share of Americans born overseas could reach the record 14.8 percent from 1890.
The current labor shortage has heightened calls for foreign workers, in fields as varied as restaurant service and nursing, to help fill vacancies.
“The pandemic offers a little taste of what we may be facing if demand is robust and we don’t have workers,” said Pia Orrenius, a senior economist who studies immigration at the Federal Reserve Bank of Dallas. “We will see price and wage inflation, and growth will be choked off.”
“Immigration is not going to make this problem go away, but it certainly could help,” Ms. Orrenius said.
If immigration had continued at a prepandemic pace, the economy would have two million additional foreign-born workers in occupations such as manual labor and computer science, according to a recent study by economists at the University of California, Davis.
While the pandemic is seen as contributing to the slowdown in new immigration, it may have also helped prop up the number of foreign-born residents since that number depends not just on how many immigrants arrive but also how many leave. Virus travel restrictions made it harder for immigrants to enter the United States, but they also made it less likely they would depart, said Jeffrey Passel, a senior demographer at the Pew Research Center.
“During the pandemic, you couldn’t leave the country basically,” he said.
Some of the growth in the foreign-born population is related to a surge of migrants at the southwestern border that has been going on, to varying degrees, since 2014. But it is almost impossible to know the full extent. Not only is there no reliable accounting of how many people are entering the country illegally, it is not clear how many of them are being quickly expelled.
The decline in birthrate that has resulted in foreign-born people becoming an ever-larger share of the population is part of a worldwide demographic pattern. Historically, nations see a drop in birthrates as they become more prosperous, a trend that can undermine that prosperity.
When low fertility is coupled with low mortality, the result is a bulging population of seniors and relatively fewer workers to sustain them, a scenario faced by Japan and many European countries that then saw their economies shrink.
The movement of the baby boom generation out of the labor force amid a plummeting birthrate has put into sharper relief the need to reverse the decline in new immigration. This will be crucial, analysts say, despite the large numbers of immigrants already living in the country — soon those here legally will be drawing more from Social Security and Medicare.
The immigrants already here may provide part of the solution. Foreign-born residents typically account for a disproportionate share of all births because recent immigrant women are more likely than others to be in their prime childbearing years and to have more children.
Lower immigration from Mexico, traditionally the biggest source of new immigrants, has contributed to falling US birthrates overall.
But it will take bold political moves to harness the economic benefits of the existing foreign-born population. Already, an estimated 11 million of them are undocumented, meaning they can work only as part of the underground economy. Mr. Biden took office with a pledge to legalize them but has failed to win bipartisan support for such a move in Congress.
He took steps to jump-start legal immigration, rescinding a proclamation by his predecessor banning the entry of foreigners on work visas.
Last month, his administration unveiled policies to attract international students and to extend the time that foreign graduates in science and technical fields can remain in the country to work, from one year to three years.
In December, the government announced that 20,000 seasonal guest worker visas would be added to the allotment of 33,000 for the winter to assist employers in landscaping, construction and hospitality, desperately in need of workers.
Yet Mr. Biden’s Republican opponents have consistently resisted large increases in new immigration, and the question of how the country moves forward is likely to be debated as campaigning picks up steam for this year’s congressional elections.