(December 2014) Next year will mark the 50-year anniversary of an important event that put the United States on a new demographic path: The end of the postwar baby boom. The U.S. baby boom was a period of remarkably high fertility rates that lasted nearly two decades, from 1946 through 1964. During this period, there were 76 million births—mostly to non-Hispanic white parents—and fertility increased to a lifetime average of more than 3 children per woman. At its peak during the late 1950s, the fertility rate reached nearly 3.7 births per woman.

The baby boom ended in 1965 when the fertility rate dipped below 3 births per woman for the first time since the mid-1940s (see Figure 1). By the early 1970s the fertility rate had dropped below 2 births per woman and the annual number of births bottomed out at nearly 1 million below the baby-boom peaks. The U.S. total fertility rate (TFR) currently stands at 1.9 births per woman, down from 2.1 at the onset of the recession in 2007. This represents the sixth straight year that the U.S. fertility rate has been below "replacement level," the level that is needed for couples to replace themselves in the population.1

Causes of Fertility Decline

The recent decline in fertility may be a short-term response to the recession and high unemployment rates. The recession disproportionately affected young adults, prompting many to delay marriage and family formation. There is a growing share of young adults—especially men—who are living with their parents instead of setting out on their own. As of 2014, 18 percent of men ages 25 to 34 were still living in the parental nest—the highest level since at least 1983.

The decline in immigration from Mexico also contributed to the drop in fertility, since recent immigrants have higher fertility rates than the U.S-born population.2 From 2007 to 2013, the fertility decline has been most dramatic among Latinas, falling from 97 births per 1,000 women ages 15 to 44 to just 73 births per 1,000 women (see Figure 2). Fertility rates have also dropped for whites and African Americans, but the declines have been smaller for those groups.

There are also longer-term societal changes at work, which may keep fertility rates low for the foreseeable future. Women are currently more likely than men to enroll in and complete college. Education affects the timing of marriages and first births, typically delaying both. Thus, the U.S. fertility rate may drop further if the share of women attending and completing college continues to increase. Among 18-to-24-year-olds, more women than men are enrolled in college in every racial and ethnic group.3

Women also make up a growing share of the labor force. The recession hit male-dominated jobs the hardest, contributing to a growing share of women who now outearn their husbands. As more women become primary breadwinners, fertility decisions are more likely to hinge on women’s earnings than they did in previous decades. A growing reliance on women’s employment and earnings could further dampen U.S. fertility rates in the coming decades.

Decline in Births Among Teens and Young Adults

The decline in U.S. fertility has been driven primarily by a trend among young adults to postpone having children. The birth rate among 15-to-19-year-olds has been cut in half between 1990 and 2013, from 60 births per 1,000 women to just 27—the lowest level ever recorded in the United States. The birth rate for women ages 20 to 24 is also down sharply, falling from 116 to 81 since 1990.

The long-term decline in the U.S. teen birth rate has been linked to delayed sexual activity and an increase in contraceptive access and use.4 In the short term, high rates of unemployment have been linked to the decline in teen births in the United States as well as in Europe.5

The sharp drop in teen births is a positive development, since children born to teen mothers are more likely to be poor, drop out of school, and be unemployed as adults.6

Looking Ahead

The U.S. fertility rate is edging closer to fertility rates in Europe, where many countries are grappling with very low birth rates and potential labor shortages down the road. However, the U.S. labor force is in a better position relative to many other developed countries because of its relatively young age structure. Despite the aging of U.S. baby boomers, the U.S. labor force is projected to increase rapidly in the coming decades, mainly because of the large numbers of young immigrants who arrive in the United States each year.

Still, a prolonged decline in U.S. fertility rates has implications for the future size of the U.S. population and labor force. The Census Bureau’s latest population projections show that the U.S. population will increase from 316 million today to nearly 400 million by 2050. But the future size and composition of the U.S. population could vary widely, depending on whether the recent declines in fertility and immigration become more permanent or revert back to their prerecession levels.

Mark Mather is associate vice president of U.S. Programs at PRB.


  1. The total fertility rate estimates the number of births a woman is expected to have during her lifetime based on current age-specific fertility rates. Replacement level fertility is the level of fertility at which a couple has enough children to replace themselves, or about 2.1 children per couple.
  2. Andrew Cherlin et al., "The Effects of the Great Recession on Family Structure and Fertility," The Annals of the American Academy of Political and Social Science 650, no. 1 (2013): 214-31.
  3. Linda A. Jacobsen and Mark Mather, "A Post-Recession Update on U.S. Social and Economic Trends," Population Bulletin Update (December 2011).
  4. John S. Santelli et al., "Explaining Recent Declines in Adolescent Pregnancy in the United States: The Contribution of Abstinence and Improved Contraceptive Use," American Journal of Public Health 97, no. 1 (2007): 150-56.
  5. Melissa S. Kearney and Phillip B. Levine, Teen Births Are Falling: What’s Going On? (Washington, DC: Brookings Institution, 2014).
  6. National Campaign to Prevent Teen and Unplanned Pregnancy, "Counting It Up: The Public Costs of Teen Childbearing."