Just have more babies? The deceptively complicated problem of the record-low U.S. fertility rate.

The U.S. fertility rate — the average number of children each woman gives birth to — fell 22% between 1990 and 2023, according to the latest data from the Centers for Disease Control and Prevention’s National Center for Health Statistics (NCHS). It’s not a new trend; the decline began in 2007, just ahead of the 2008 recession. Coupled with the rapidly aging American population, the falling fertility rate has long made policymakers nervous about draining Social Security funds and generally causing economic turmoil due to a shrinking labor force.

Is the solution that Americans should be having more babies? And should we be worried about the drop in fertility rates in the first place? The problem is more complex than that, according to three experts who think about shifting demographics, populations and fertility for a living.

What’s happening?

In 1990, each woman had an average of 2.08 children. By 2023, that figure had fallen to 1.62. The number of babies born each year has fallen by 14% over the same time frame, resulting in 562,195 fewer births in 2023 compared to 1990.

That decline is driven by a dramatic fall in the number of teenagers having babies. In 1990, 1.4 babies were born to every 1,000 girls between ages 10 and 14. By 2023, that number had fallen to just 0.2. And the birth rate per 1,000 women between ages 15 and 19 fell by 78%.

Historically, low teenage pregnancy and birth rates are considered a public health win. “If a teenaged person gets pregnant and wants to keep the baby, they should have that right, but most teen pregnancies are unintended or unwanted, and it’s absolutely a good thing that people are getting good at preventing births they don’t want to have,” Leslie Root, a demographer and associate director of the Colorado University Population Center, tells Yahoo Life. The reduction in unintended teen pregnancies is thanks in large part to better contraceptives and improved access to them for young women.

The problem

Fewer teenage pregnancies means those young women are more likely to graduate high school, remain in good health and avoid poverty — positive indicators for their individual lives and for the economy. But the downturn in teenagers having children also contributes to an overall birth shortage. Despite increases in the number of babies born to women in their 30s and 40s, there aren’t enough births among these age groups to make up for the babies teens aren’t having.

That presents a problem because it puts the fertility rate below 2.1 children per woman, a figure known as the rate of replacement. The rate of replacement is the result of some very simple population math: It takes two children to “replace” each of their two parents in order to maintain the future population (plus the .01 to account for the possibility of children dying young). Currently, the fertility rate is at 1.62 children per woman. That’s too few to replace the number of parents in the population as they retire and, eventually, die.

Maintaining the number of people in a nation’s population — or the global population, for that matter — is mostly important for economic reasons. If there are more nonworking retired people or children than there are working-age people, Social Security funds will get depleted, and there won’t be enough people paying into them to restore the coffers.

“I think there is reason for concern,” Phillip Levine, a Wellesley College economics professor, tells Yahoo Life. “Having a birth rate this low definitely has implications for society more broadly, including economic activity.” Fewer workers are likely to generate less output. When populations shrink, creativity and innovation sometimes slow. “And our Social Security system is completely dependent upon there being more children” who will grow up to contribute to the retirement safety net, says Levine.

Give me some context

For starters, this isn’t new. Fertility rates have been declining for nearly 20 years in the U.S., and we haven’t been above the rate of replacement since 2007. The phenomenon also isn’t unique to American families. The global fertility rate is falling, and the rate is below replacement level in about two-thirds of countries.

That’s not altogether bad. “My overall take on it is that the falling fertility rates around the world and throughout history is great,” Philip Cohen, a University of Maryland professor of sociology, tells Yahoo Life. “It’s been incredibly important for social progress, it increases opportunities for children, gives people more choices for how to run their families and has opened up the professional world for women.” The greater share of women in the labor force is a boon for the economy too, and means more income tax dollars paid into state and federal budgets.

But eventually, the ratios will flip. Women (and men) who are working now will retire. The important thing for maintaining a stable population isn’t so much the number of babies, but the ratio of working to nonworking people. That ratio was actually furthest out of balance following the arrival of baby boomers, those born between 1946 and 1964, when less than 50% of Americans were of working age. In 2023, just shy of 54% of Americans were working age. But as boomers reach retirement age and birth rates remain low, there will be fewer newly adult workers to replace those boomers. In order to ensure economic stability, the U.S. will need more workers.

What can be done?

There are two main ways to ensure the U.S. population — or any country’s — doesn’t shrink, experts tell Yahoo Life: babies and immigration.

Since 2015, immigrants and their children have accounted for most of the growth in the working-age population of the U.S. It’s by far the easiest and fastest way to grow the population. In 2022, 77% of immigrants to the U.S. were of working age, compared to 58% of U.S.-born population. Immigrants, by and large, arrive as ready-to-work adults.

On the other hand, making babies into workers is a slow, expensive process. “Producing more babies today is going to cost you trillions more dollars before they reach working age,” which takes upwards of 18 years, says Cohen. And, coupled with the rising number of baby boomers leaving the workforce, “the birth rate rising now would only make things worse” because it would mean more dependents,” he adds. “The only problem for the American birthrate and the population size is if you prefer American babies to immigrant workers.”

In this sense, increasing the birth rate is the simpler option. “Immigration is something that can quickly fill spots in the workforce, but it is, and always has been, political,” Jennifer Sciubba, a demographer and author of 8 Billion and Counting: How Sex, Death and Migration Shape Our World, tells Yahoo Life.

Demography experts agree that governmental efforts to incentivize people to have children, also known as pronatalist policies — such as paid parental leave, free early child care and child tax credits — are generally good for society. Other countries with declining birth rates and populations, including Japan, Finland, China and Hungary, have tried to institute pronatalist policies to encourage population growth, but, Sciubba says: “We don’t see a lot of success with countries that put into place pronatalist policies in actually turning around birth rates,” says Sciubba. “There’s not a lot that country governments can actually do.”

While there’s reason to be concerned about the national and global declines in population, Cohen says it’s unrealistic to expect the problem to be solved by telling people to have more children. It might work at the margins, but is unlikely to persuade enough families to meaningfully move the birth-rate needle. “People don’t have children for the greater good," he says. "They never did.”