Posted on January 25, 2021

What the 2020 Census Will Reveal About America

William H. Frey, Brookings Institution, January 11, 2021

Over the coming months, the U.S. Census Bureau will roll out the results of the 2020 census, its once-a-decade headcount that will give us precise details on the size, growth, age, and racial-ethnic makeup of the nation’s population. In the lead-up to that over the past year, the Bureau has released the results of other large surveys and studies, which I have analyzed to pinpoint key demographic trends that the decennial census is likely to confirm.

These trends include an unprecedented stagnation in population growth, a continued decrease in Americans’ geographical mobility, more pronounced population aging, a first-time decline in the size of the white population, and rising racial and ethnic diversity among millennials, Gen Z, and younger groups, which now comprise a majority of the nation’s residents. Below, I recap those trends and conclude by examining alternative Census Bureau projections that reinforce the crucial role immigration will play in future population growth.



The most recent Census Bureau estimates by race show a small decline of 16,612 in the nation’s white population over the 2010-to-2019 period. If this trend is confirmed with the full 2020 census, the 2010-to-2020 decade would be the only decade since the first census was taken in 1790 when the white population did not grow.

This decline in the white population is a major driver of the nation’s demographic stagnation. White population gains in recent decades have grown smaller over time, from 11.2 million between 1970 and 1980 down to 2.8 million between 2000 and 2010. But a white population loss between 2010 and 2020 would be unprecedented.

The white population decline is largely attributable to its older age structure when compared to other race and ethnic groups, leading to fewer births and more deaths relative to its population size. In 2019, the median age for white Americans was 43.7, compared to 29.8 for Latino or Hispanic Americans, 34.6 for Black Americans, 37.5 for Asian Americans, and 20.9 for persons identifying as two or more races. While white fertility may have taken an accentuated dip due to delayed marriage and childbearing for millennials—whose lives continued to impacted by the Great Recession—the long-term decline projected in the white population is due to its increased aging.

This means that other racial and ethnic groups are responsible for generating overall population growth. The U.S. grew by a total of 19.5 million people between 2010 and 2019. Latinos or Hispanics contributed 10 million people to that total—over half of the nation’s growth. Asian Americans, Black Americans, and persons of two or more races contributed 4.3 million, 3.2 million, and 1.7 million people, respectively. These groups constituted the main engines of the nation’s growth, and are likely to do the same going forward.


Census Bureau population estimates released last year revealed that more than half of the nation’s total population are now members of the millennial generation or younger. And while these younger generations—born in 1981 or later—are not growing as rapidly as older age groups, they are far more racially diverse.

One reason for this is that the white population declines discussed above are more pronounced among the young. Since 2000, the under-18 white population registered absolute population losses. Meanwhile, millennials and their juniors were born during years of higher immigration. In many ways, from the 1980s through the early 2000s, immigrants and their children have contributed to both the growth and diversity of the nation’s younger population—however, more recently, natural increase rather than immigration is the primary source of Latino or Hispanic population growth.

This has led to stark generational differences in diversity. About 60% of the U.S. population identifies as white alone; that figure reaches more than 70% for baby boomers and their elders, but only about half for the combined Gen Z and younger populations, with nearly two-fifths of those groups identifying as “Black or brown.”

These generational differences are important for public and private sector planning, especially with respect to the needs of the increasingly diverse younger population. The generational divide in diversity also fosters what I have called a “cultural generation gap,” which has impacted politics in ways that are sometimes divisive. It is important to understand that as these younger, diverse generations age, their tastes, values, and political orientations will become the nation’s “mainstream.” {snip}



{snip}  The main projection suggests that if current trajectories of fertility, mortality, and immigration persist, U.S. population growth between 2020 and 2060 would be 22% (to 404 million people). That is half the 44% growth rate of the previous four decades.

This projection assumes an annual immigration level roughly twice that of the year before the pandemic. If that lower immigration level were to persist, growth from 2020 to 2060 would be reduced to just 14% (376 million people) for an average annual growth rate of 0.32%. (A projection assuming zero immigration would lead to a net decline in the U.S. population over that 40-year period.)

An even larger consequence of lower immigration would be a stagnating youth population. Under the Census Bureau’s main projection, between 2020 and 2035, the nation’s under-18 population would grow by 4%. But under its low-immigration projection, there would be zero growth in the under-18 population. In both projections, the over-65 population would grow by at least 38%.

One way to secure more rapid growth of the youth population would be to increase immigration to three times the current level. Under this scenario, the youth population would increase its growth to 9% over the next 15 years.