Policy Documents

Projecting Immigration’s Impact on the Size and Age Structure of the 21st Century American Population

Steven Camarota –
December 2, 2013

Steven Camarota examines census data to find that immigration makes for a much larger overall population, while having only a small effect on slowing the aging of American society.

Among the findings:

  • If immigration continues as the Census Bureau expects, the nation's population will increase from 309 million in 2010 to 436 million in 2050 — a 127 million (41 percent) increase.
  • The projected increase of 127 million is larger than the combined populations of Great Britain and France. It also exceeds the entire U.S. population in 1930. 
  • The Census Bureau assumes net immigration (legal and illegal) by 2050 will total 68 million. These future immigrants plus their descendants will add 96 million residents to the U.S. population, accounting for three-fourths of future population growth. 
  • Even if immigration is half what the Census Bureau expects, the population will still grow 79 million by 2050, with immigration accounting for 61 percent of population growth.
  • Without any immigration, the U.S. population will increase by 31 million by 2050. 
  • Though projections past 2050 are much more speculative, if the level of immigration the Census Bureau foresees in 2050 were to continue after that date, the U.S. population would reach 618 million by 2100 — double the 2010 population. 
  • The immigrant (legal and illegal) share of the population will reach one in six U.S. residents by 2030, a new record, and nearly one in five residents by 2050. 
  • The above projections follow the Census Bureau's assumptions about future levels of immigration, as well as death and birth rates, including a decline in the birth rate for Hispanics.
  • Consistent with prior research, the projections show immigration only slightly increases the working-age (18 to 65) share of the population. Assuming the Census Bureau's immigration level, 58 percent of the population will be of working-age in 2050, compared to 57 percent if there is no immigration.
  • Raising the retirement age by one year would have a larger positive impact on the working-age share over the next 40 years than would the Census Bureau's total projected level of net immigration (68 million). 
  • While immigrants do tend to arrive relatively young and have higher fertility than natives, immigrants age just like everyone else, and the differences with natives are not large enough to fundamentally increase the share of the population who are potential workers. 
  • The Center for Immigration Studies, as well as other researchers, has reported that immigration levels have fallen somewhat in recent years. While there is no way to know if the level will remain lower, this change can be incorporated into these projections.
    • Assuming immigration is one-third below what the Census Bureau's expects for 10 years (2010-2020) produces a total U.S. population of 428 million in 2050 — a 118 million increase over 2010. By itself immigration would account for 87 million additional U.S. residents under this scenario.
    • A one-third reduction in the Census Bureau's level of immigration over the entiretyof the next four decades (2010-2050) produces a total U.S. population of 404 million in 2050 — a 95 million increase over 2010. By itself immigration would account for 64 million additional U.S. residents under this scenario.
  • Because the underlying level of immigration is so high, even a one-third reduction in what the Bureau expects over the next four decades would still add tens of millions of new residents to the U.S. population and account for most of the population growth. 
  • The importance of immigration to population growth can be seen by projecting the impact of reduced fertility. If the fertility of natives were to fall 20 percent more than the Census expects by 2030, but immigration continued at the pace the Bureau expects, the U.S. population would still grow to 409 million by 2050 — a 99 million increase over 2010. 
  • Immigration is a discretionary policy of the government and can be changed. The fundamental question for the American public and policy makers is whether a much larger population and the resulting greater population density will add to or diminish the quality of life in the United States.