America’s population growth slows to a crawl

The number of people living in the United States grew by the slowest rate over the last decade than in any other decade in American history, worrying demographers who see a graying population harming long-term economic growth.

The nation’s population grew by just 6.6 percent over the last decade, according to new estimates from the U.S. Census Bureau released on Tuesday, to about 329.2 million people. That growth rate is lower even than the 7.3 percent increase that occurred in the decade of the Great Depression. 

In more recent decades, the United States has added between about 10 percent and 17 percent to its population between Census periods.

In the past year, the United States added only about 1.1 million residents, a growth rate of 0.35 percent — the lowest since the Census Bureau started making annual estimates 120 years ago.

“These new census estimates reveal a nation grappling with demographic stagnation to a degree it has not experienced in quite some time,” said William Frey, a senior demographer at The Brookings Institute.

Slowing growth rates are a result of several overlapping phenomena, demographers said, both of which pose a threat to future growth.

One is an ongoing baby bust, in which the average American woman is giving birth to fewer children and beginning at a later age. The birth rate in the United States has fallen to its lowest levels in 35 years, according to data from the Centers for Disease Control and Prevention.

The other is a substantial drop-off in the number of immigrants who come to the United States. Federal data show the number of immigrants who moved to America dropped by about two-thirds from the last years of the Obama administration to the first years of the Trump administration, and recent Census data suggests the number of immigrants moving in has fallen even further. Immigrants tend to be younger than the nation as a whole, and more likely to have children.

The resulting confluence is an aging population which, as members of the Baby Boom generation age into retirement, will come to rely more on younger workers for support — at the same time the younger population is drying up. 

“This is a human resource issue. We need more people to be in those younger populations,” Frey told The Hill. “The aging of the population means more deaths, fewer births, and it makes immigration a much more important factor.” 

The last decade has hastened a longer-term trend of Americans moving out of Northeastern and Rust Belt states and into Sun Belt and Western states. Sixteen states lost population over the last year and six states are smaller today than they were when the last Census was completed a decade ago. 

Illinois experienced an exodus of more than a quarter million people in the last decade, the new Census estimates show. Nearly one in every 25 West Virginia residents moved out over the last decade. New York, Connecticut and Vermont all lost population, as did Mississippi.

Thirteen states and the District of Columbia saw their populations boom by more than 10 percentage points over the last decade. The nation’s capital added more than 107,000 new residents, a 17.8 percent spike, though that growth has slowed near the decade’s end. Utah’s population also ballooned more than 17 percent.

No state added more residents than Texas, where 4.1 million people moved over the last ten years. Texas stands to add three seats to its congressional delegation after the next round of reapportionment, according to recent estimates.

Florida and California added more than 2 million residents each over the last decade. But their relative trajectories are starkly different: Florida added almost a quarter million residents in just the past year, an increase of about 1.1 percent. California saw an out-migration for the first time in its history, as net of about 70,000 residents left the state between 2019 and 2020.

California’s net out-migration, Frey said, is likely a function of the lower immigration rates during the Trump years. California residents have been leaving the state for years, but until recently they have been replaced at a faster pace by those moving in from other countries.

Southern states added more than 12 million residents over the last decade, led by growth in Texas and Florida. Western states added 6 million residents, as states like Arizona, Nevada, Idaho, Colorado, Washington and Oregon all grew by more than 10 percentage points.

At the same time, Midwestern states added just 1.4 million new residents, and Northeastern states added only half a million, relative stagnation in regions that were once home to a majority of Americans. 

It is not immediately clear how the coronavirus pandemic may have slowed population growth. The new Census Bureau estimates ran through July 1, 2020, about four months into the pandemic, meaning they could have picked up some slowing population growth and even some of the early deaths caused by the virus. 

But the longer-term trends of slowing population growth is enough to alarm demographers who worry about an aging population relying on fewer younger workers to maintain the social safety net.

“Growth is good anyway, but the decline in growth is going to be concentrated in the youth population and the younger labor force population,” Frey said. “What it means is increased age dependency.”