Fewer Babies, Older Populations – How the U.S. and World Face a Pivotal Demographic Shift in 2025

A mother carries her young child on her back outdoors, reflecting family bonds in a time of fewer babies and changing demographics

Many researchers argue this shift is rooted in a positive development: women and young couples now have greater freedom and economic independence, leading to different choices about having children.

โ€œItโ€™s not that people suddenly dislike kids,โ€ said Melissa Kearney, an economist studying fertility at the University of Notre Dame. โ€œThey simply have more options now, whether thatโ€™s investing in careers or enjoying leisure time, and itโ€™s more socially acceptable.โ€

This behavior change is accelerating. Recent United Nations research shows global fertility has fallen to its lowest recorded level, with women worldwide having less than half the children they did in the 1960s.

โ€œIn higher-income countries, birth rates have dropped rapidly and consistently,โ€ Kearney said. โ€œWe are facing real questions about declining populations.โ€

The Shift in American Families


In the U.S., this trend is reflected in rising numbers of women opting out of motherhood. According to Kearney, half of American women now reach age 30 without having a child, compared to one-third two decades ago. Families are also choosing to have fewer children overall.

โ€œI remember thinking, โ€˜I definitely want three kids,โ€™ just like my mom,โ€ said Lusely Martinez, 35.

Martinez cherishes motherhood. โ€œWatching our child grow and discover is magical,โ€ she said. But after many conversations, she and her husband chose to have only one child.

โ€œRaising a child is so expensive,โ€ Martinez noted. โ€œWe had to stop and think about whether having more made sense.โ€

Tracking the Numbers

A straightforward way to measure this societal change is by looking at the โ€œtotal fertility rate,โ€ the number of children a woman will have in her lifetime.

A stable population requires an average of 2.1 children per woman. In the U.S., fertility dipped below this level years ago and, post-2007, dropped sharply to a record low of around 1.6.

โ€œI donโ€™t have a specific number that would trigger panic,โ€ said Kearney. โ€œBut seeing so many young adults remain childless worries me that weโ€™re missing something important as a society.โ€

From Population Bomb to Population Decline

Colorful paper cutouts of people arranged in a pattern show the trend toward smaller families and population decline
The U.N. notes fewer teen and child pregnancies and more economic freedom for women

The shift toward lower birth rates and aging populations is striking, especially after decades of warnings about overpopulation and its environmental consequences.

In the 1960s and 1970s, scientist Paul Ehrlich warned of a looming โ€œpopulation bombโ€ threatening the world.

โ€œNo responsible American family should have more than two children,โ€ Ehrlich said in a 1970 interview, describing overpopulation as a fatal threat to crowded U.S. cities.

Now, many demographers say that the bomb has fizzled, and a long-term trend toward smaller populations could reduce environmental strain.

There are upsides to declining fertility: the U.N. reports a significant global drop in teenage and child pregnancies, alongside growing economic freedom for women.

โ€œOne of the major global health successes in the past 30 years has been the drop in adolescent birth rates,โ€ said Vladimรญra Kantorovรก, the U.N.โ€™s chief population scientist.

Concerns About a Shrinking World

But the rapid decline in birth rates, with some countries seeing rates fall to extreme lows, worries many experts.

โ€œIn places like South Korea, the birth rate is practically nonexistent,โ€ said economist Phillip Levine of Wellesley College. U.N. projections indicate that by mid-century, 40% of South Koreaโ€™s population will be over 65.

โ€œNo one anticipated fertility dropping this far,โ€ Kantorovรก said. โ€œWeโ€™ve never experienced such a prolonged decline before.โ€

While longer life spans mean the global population will continue to grow for now, these trends will lead to population declines later this century.

Countries like China, Italy, Japan, Russia, and South Korea are already seeing shrinking populations. China is projected to lose over 780 million people by 2100.

โ€œItโ€™s uncertain if these steep declines will happen everywhere,โ€ Kantorovรก said.

The U.S. and Immigrationโ€™s Role

Despite record-low fertility, the U.S. population has remained stable thanks to immigration, but data shows a shifting demographic landscape. In 11 states, people over 65 now outnumber children, up sharply from just three states five years ago.

โ€œChildren still outnumber older adults nationwide, but the gap is closing as baby boomers age,โ€ said Lauren Bowers of the Census Bureau.

A Brookings Institution study in 2023 found that without immigration, the U.S. population would drop by over 100 million this century.

โ€œWithout immigration, weโ€™d lose about a third of our population by 2100,โ€ said study author William Frey.

โ€œWhat happens to our workforce? To productivity?โ€ Frey asked. โ€œWeโ€™ll have jobs without enough people to fill them, increasing the need for immigration.โ€

A Push Toward Prenatal Policies

Some politicians and activists are advocating for policies to encourage higher birth rates, known as pronatalism.

Lyman Stone of the Institute for Family Studies supports child tax credits and flexible work to make parenting more affordable, arguing many young people want kids but face barriers.

โ€œThey arenโ€™t marrying early enough, buying homes early enough, or securing stable jobs in time,โ€ Stone said. โ€œSo they fall short of their desired family size.โ€

Vice President Vance declared, โ€œI want more babies in America,โ€ during a March for Life speech, while Elon Musk has called declining birth rates a threat to civilization, urging people to have at least three children.

Can the U.S. Support Families for the Future?

A smiling family holds an American flag together, highlighting questions about supporting families in the U.S. future
Raising birth rates will need big policy shifts like paid leave and affordable healthcare

Martinez doubts the U.S. will address underlying issues like high housing, healthcare, and childcare costs that discourage larger families.

โ€œWhy focus on increasing births if you arenโ€™t going to support families afterward?โ€ she said.

Experts agree that encouraging higher fertility will require significant policy changes to make parenting viable, from paid leave to affordable healthcare.

โ€œWithout a serious response, itโ€™s not only possible but likely that fertility rates will continue falling,โ€ Kearney said. โ€œAnd Iโ€™m more worried about that than many others waiting to see if weโ€™ll hit a point of no return.โ€