December 14, 2012

Census Bureau Lowers U.S. Growth Forecast, Mainly Due to Reduced Immigration and Births

The Census Bureau’s new national population projections released this week forecast markedly lower growth for the nation in the coming decades—especially from immigration—than the last official projection in 2008. In fact, the bureau’s new projected population of 420.3 million in 2060 is below its previous projection of 439 million for a decade earlier, in 2050. The bureau’s new projected population for 2050 is 399.8 million.

The 2060 population figure, which represents a 34% increase from the U.S. 2012 population of 314 million, assumes that annual growth will range from just below 2 million to 2.5 million. That is decidedly less than in 2008, when the bureau assumed the nation would add about 3 million to 3.4 million people each year through 2050, the final year in that set of projections.

Population projections are created from underlying assumptions about the nation’s future net immigration, birth rates and death rates. Formulating new population projections is especially challenging now because the Great Recession that began in 2007 has helped to slow immigration and births. Immigration levels have come down since a peak in 2001, and unauthorized immigration began falling around 2007. Birth rates, already decreasing in recent decades, declined sharply after 2007. But are these recession-related declines a short-term blip or do they represent a long-term swerve?

A comparison of the bureau’s 2008 and 2012 projections for the year 2050 indicates that most of the 39.2 million gap in the total population forecast is due to scaled-back assumptions about the level of new immigration to the U.S. But another notable factor in the lowered population projection was that the bureau also lowered its forecasts for birth levels.

Immigration Rate Lessens

The Census Bureau projects the population by age, sex, race and Hispanic origin only. The bureau does not publish projections for the size of the immigrant population, but the agency incorporates into its overall projections assumptions about annual net immigration—the sum of how many immigrants arrive minus how many leave or die.

In its new projections, the bureau assumes that the U.S. population will gain a total of 41.2 million net new international migrants from 2012-2050. In its 2008 projections through 2050, that number was 65.6 million. As this chart shows, the difference—24.4 million—represents more than 60% of the reduction in total U.S. population size for 2050 in the 2012 projections compared with those in 2008.

Not only did the bureau lower the number of new immigrants it expects to arrive, it also changed the way it calculates its immigration forecasts. Instead of using only U.S. data, the bureau incorporated information on population trends in sending countries, which it collects in its International Data Base.

Future rates were calculated using a weighted average of rates that prevailed from 1980 to 2010, so the projections incorporate both recent sharp reductions in immigration and a longer-term pattern of increases.

Overall, the projections estimate that net immigration levels will rise to 1.2 million a year in 2060 from 725,000 in 2012. In the new projections, the growth of the foreign-born population increases less and less rapidly over time and virtually levels off by mid-century. In the 2008 projections, annual net immigration was about 1.3 million in 2012 and increased to 2 million in 2048, growing briskly each decade. (Net immigration from abroad includes a small number of people born in the U.S. or its territories, but not enough to affect totals.)

The Census Bureau projections group countries into four regions, in order to categorize immigrants from those areas by race and Hispanic origin for use in the overall projections. Although Asian Americans have been the largest group of newly arriving immigrants since at least 2009, the bureau projects that Hispanics will have the largest net immigration in all future decades through 2060. However, by 2050, net migration by black immigrants is projected to overtake net immigration by white immigrants, so black net immigration will rank third by 2060, after Asian net immigration.

The Census Bureau plans to release a set of alternative assumptions about immigration next year, including options showing immigration at higher levels and lower levels than shown in the current projections.

The Pew Research Center released its most recent population projections in 2008, concluding that the U.S. population would reach 438 million in 2050, a 48% increase over the projection’s starting point in 2005. The Center is planning to update these projections in 2013, including more detail than the Census Bureau does about the size and characteristics of the immigrant population, and its descendants.

Births Rates Decrease

The Census Bureau’s new projections include a population gain from births by 2050 that is 17.8 million lower than it had forecast only four years ago. From 2012 through 2050, the Census Bureau projects a total of 175.4 million births, compared with 193.2 million in its 2008 projections.

The bureau’s 2008 projections were based on birth rate data through 2003, but those projections missed a marked decline in births that began after 2007, especially among immigrant women. From 2007 to 2011 (the 2011 data are preliminary), the nation’s birth rate, which already had been decreasing for decades, fell sharply to a record low. The bureau’s new projections incorporate this change.

The bureau’s reduced immigration projection also drives its reduced projection of births. Immigrant women are more likely than U.S.-born women to be in their childbearing years. They also on average have more children in their lifetimes.

In 2008, the bureau projected there would be about 4.3 million births in 2012 and more than 5.6 million in 2050. In 2012, the projections estimate a slightly lower 4.2 million births in 2012 and a markedly lower 4.8 million in 2050. (The 2012 figure would represent the first increase in births since 2007, so may turn out to be too high.)

The Census Bureau projection included a forecast for the total fertility rate, which is the expected number of children that a typical woman will have during her lifetime, based on current-year birth rates for each age group. The total, 2.0 in 2012, is projected to decline to 1.91 by 2060. By then, the Census Bureau said, but only the Hispanic population will have a rate (2.15) large enough to replace itself.

Deaths and Population Base

The Census Bureau also made adjustments to the third major underlying assumption in its population projections, the number of deaths. In general, life expectancy has been increasing. From 2012 to 2050, the projections assume a total 128.4 million deaths, compared with 133.1 million deaths by 2050 that were assumed in the 2008 projections, a slight difference.

Another minor factor in lowering the long-term projections was that the bureau used as its starting point a slightly lower population estimate for 2011 than had been projected in 2008. The starting point for the new projections was a U.S. population of 311.6 million, which is 1.6 million lower than the bureau had projected in 2008 that it would be.

In a posting on the bureau’s Random Samplings blog, the bureau’s Jennifer M. Ortman explained that the agency has tried to strike a balance between recent trends and longer-term trends in making assumptions about immigration and births. For death rates, she said, the bureau assumed that recent declines in old-age mortality will continue to some extent.

It matters whether the Census Bureau projections get it right, because projections have a wide variety of uses. Ortman wrote: “A topic of great interest is the aging of the population. Projections of the old-age population are of particular interest for those assessing government programs such as Medicare and Social Security. Projections of the working-age population, typically between the ages of 20 and 64, are of interest to businesses and service providers attempting to evaluate future demand for their products and services as well as the means of supplying those goods. Projections of births and the population under the age of 18 are of interest to educators tasked with planning for future demands on the education system.”