Covid-19 Drives U.S. Population Growth to Record Low

The new estimates show the pandemic’s fallout after its first year as Covid-19 became the nation’s third-leading cause of death. Population growth had been slowing before the pandemic, but it had averaged more than 2 million a year over the last decade. As recently as 2016, the country grew by 2.3 million people.

Birthrates have fallen steadily since the 2007-2009 recession. Death rates had edged up, especially in states hit hardest by the opioid epidemic. And immigration dropped in recent years under policies set by the Trump administration.

“Covid’s just exacerbated a difficult situation,” said Kenneth Johnson, a demographer at the University of New Hampshire.

Seventeen states lost population, led by New York (-1.6%), Illinois (-0.9%) and Hawaii (-0.7%). California, which recorded only its second decrease ever after logging its first last year, dropped by 0.7%. The District of Columbia’s population dropped 2.9%.

More broadly, the Midwest lost 0.1% and the Northeast lost 0.6%. The West was essentially flat, while the South gained 0.6%. Texas, the largest Southern state, gained 1.1%. States that grew the most included Idaho (2.9%), Utah (1.7%) and Montana (1.7%). Florida, Texas, and Arizona saw the largest gains from domestic moves as the pandemic prompted more people to uproot for warmer areas with low taxes.

Net international migration to the U.S. remains relatively low despite a record number of attempts to cross the southern border illegally. This year’s figure was just over half the size of the prior year’s total, when net new residents from abroad totaled 477,000. As recently as 2016, that figure was more than 1 million a year. The figures also include Americans moving to and from the U.S.

Most of those caught trying to cross the border illegally are being sent back, while the pandemic has slowed legal immigration channels, with visa processing at about half normal levels and the refugee-admissions program at a standstill. Census figures include people residing in the U.S. illegally, though their exact numbers can be difficult to pin down.

Prof. Johnson said that deaths exceeded births in half of states during the time period covered by the new data. Population growth is expected to remain low because the aging population is likely to pressure mortality rates and because the lull in births appears to be continuing, he said.

“It will ripple up through the school system and the universities and eventually hit the labor force,” he said. “We’ll look more like Europe.”

Even before the pandemic, the surplus of births over deaths was narrowing as the population got older and births dwindled. In the year that ended July 1, the bureau used birth and death certificates to estimate 3.58 million births and 3.43 million deaths. In 2015, it estimated 4 million births and 2.7 million deaths.

The estimates themselves also were affected by the pandemic, which has delayed detailed 2020 census data on which the estimates would normally be based. Instead, the bureau used limited 2020 census totals and other sources, such as birth and death certificates. The bureau is required to publish the estimates each year to help state and local governments in budgeting and distributing aid. The estimates also underpin disease and death rates.

Despite slowing growth, projections by the Census Bureau and the United Nations show the U.S. population is expected to continue growing at least through the middle of the century. By comparison, populations have begun to shrink in Japan, Russia and many European countries, including Germany, Poland and Portugal. China’s population is expected to peak before 2030.

Write to Paul Overberg at Paul.Overberg@wsj.com and Janet Adamy at janet.adamy@wsj.com