More than 73 percent (2,297) of U.S. counties experienced a “natural decrease” in population in 2021, up from 45.5 percent in 2019 and 55.5 percent in 2020 at the height of the COVID-19 pandemic, according to the U.S. Census Bureau’s Vintage 2021 estimates of population and components of change.
A natural decrease in population happens when more deaths occur than births over a given period of time, in this case from July 2020 to July 2021.
Fewer births, an aging population, and increased mortality further exacerbated by the pandemic also contributed to a hike in natural decrease, according to the Census Bureau.
The bureau’s data cover 3,143 counties, 384 metropolitan statistical areas, and 543 micropolitan statistical areas across the nation.
In 2021, all counties in Delaware, Maine, New Hampshire, and Rhode Island experienced more deaths than births, according to the data.
The bureau’s data suggest that some counties experienced population declines because of migration, as many Americans relocated to less populous or less expensive areas during the pandemic.
The states of Alaska (80.0 percent), Louisiana (71.9 percent), and Illinois (65.7 percent) had the highest percentages of counties with net domestic migration loss, which is when people move from one area of the United States to another.
Overall, most counties (2,063 or 65.6 percent) experienced “positive domestic migration” from 2020 to 2021, meaning that there were more people entering than leaving those areas.
Arizona’s Maricopa County welcomed the most residents from domestic migration, at 46,866, followed by Riverside County, California, with 31,251, and Collin County, Texas, with 30,191 residents.
Los Angeles County, California, experienced the greatest net domestic migration loss with 179,757 residents, followed by New York County in New York with 113,642.
New York was, at one point in the spring of 2020, the epicenter of the COVID-19 pandemic in the United States.
“The patterns we’ve observed in domestic migration shifted in 2021,” said Dr. Christine Hartley, assistant division chief for estimates and projections in the Census Bureau’s Population Division. “Even though over time we’ve seen a higher number of counties with natural decrease and net international migration continuing to decline, in the past year, the contribution of domestic migration counteracted these trends so there were actually more counties growing than losing population.”
Micro areas in the United States, or smaller locales, diverted from previous trends, experiencing a slightly faster growth (0.2 percent between 2020 and 2021) than metro areas, which increased by 0.1 percent.
Among metro areas, 251 (65 percent) experienced population increases between that time period, while 287 (52.9 percent) of the 543 U.S. micro areas saw population increases in 2021.
Of the 384 metro areas in the 50 states and Washington, 213 (55.5 percent) experienced a natural decrease in 2021, among which Pittsburgh, Pennsylvania (-10,838); Tampa-St. Petersburg-Clearwater, Florida (-9,291); and North Port-Sarasota-Bradenton, Florida (-6,643) had the highest levels.
Overall, five of the top 10 largest-gaining counties in 2021 were in Texas in the counties of Collin, Fort Bend, Williamson, Denton, and Montgomery. They gained a combined total of 145,663 residents.
Los Angeles County, which has had the highest number of deaths from COVID-19, experienced the largest population loss of any county, losing a total of 159,621 residents in 2021.
Only the decade spanning the 1930s—when the Great Depression occurred—had a slower growth rate.