US population will start decline before 2100, data show

Projected to continue toward greater diversity

Before the end of the century, the US population will stop growing for the first time in the country’s history and start to decline, new Census Bureau data show.

The bureau’s 2023 National Population Projections estimate that the population will peak at almost 370 million in 2080 before receding to 366 million in 2100, an increase of only 9.7 percent between 2022 and 2100. That is far below the rate the country has grown each decade for most of the nation’s history.

The data, released Thursday, are the first such updates since 2017 and the first to reflect the effect of the coronavirus pandemic. They paint a stark picture of how immigration policy could affect the country’s path.

The projections are based on assumptions about births and deaths, which are relatively stable as they are based on fertility rates and the age of the population. They also are based on net international migration, which can fluctuate in less predictable ways.

Immigrant adults tend to be younger and have higher fertility rates than their native-born counterparts. Demographers say they are key to providing enough people to fill the labor force and balance out the swelling population of older Americans, and avoid the fate of countries such as Japan and Germany, which have among the world’s highest share of people over 65.

“These projections make clear that immigration is absolutely essential to the nation’s future population growth,” said William Frey, a senior demographer at the Brookings Institution who analyzed the data. “It is also necessary to counter the extreme aging we will otherwise experience with the youthfulness of immigrants and their children.”

The new numbers reflect a steeper decline than previous projections, said Sandra Johnson, a demographer at the Census Bureau.

“The US has experienced notable shifts in the components of population change over the last five years,” she said. “Some of these, like the increases in mortality caused by the COVID-19 pandemic, are expected to be short-term — while others, including the declines in fertility that have persisted for decades, are likely to continue into the future.”

The bureau’s projections include four possible scenarios of population change by 2100, based on high, medium, low, and zero immigration to the United States.

In the most likely scenario, the population is projected to reach 366 million by 2100. The projection for the high-immigration scenario puts it at 435 million; the low-immigration scenario puts it at 319 million by the end of the century.

The zero-immigration scenario, which the bureau said is "largely illustrative," projects that the population would start to decline next year and would dip to 226 million in 2100, around 107 million lower than the 2022 estimate.

Frey’s analysis shows that even under the likely immigration scenario, which assumes an annual net migration between 850,000 and 950,000, growth in subsequent decades will be sharply reduced, from 4.1 percent in 2020-2030 and 3 percent in 2030-2040 to 1.5 percent or less in the decades through 2080. Low immigration of around 350,000 to 600,000 annually, similar to the years before the pandemic, would lead to population declines starting in 2044.

The population will also age considerably, Frey’s analysis showed. Under all scenarios except the high-immigration one of about 1.5 million people a year, the nation’s under-18 population will continue to decline.

"This is especially significant between now and 2035, when immigration of young adults and their children will make the difference between growth or decline in the labor force-aged population, while baby boomers swell the retirement-aged ranks," Frey said.

The country is also projected to continue its trajectory toward greater diversity. The 2020 Census marked the first time the number of people who identify as white alone had shrunk since a census started being taken in 1790. It’s also the first time the portion of white people dipped below 60 percent. The under-18 population is now majority people of color.