The Politics of Population
Fertility, Demographics, and the Shrinking Future
By James Halsell
When I registered for classes for the spring semester at Johns Hopkins School of Advanced International Studies (SAIS) in 2024, I found myself needing one more course to round out my schedule. After scouting the course catalog, I settled on a course called The Politics of Population, taught by German-American Political Scientist Yascha Mounk. It wasn’t a topic I’d ever really considered that deeply, and the title was just ambiguous enough to make it seem moderately interesting. After reading the syllabus, skimming some of Mounk’s work online, and reading an excerpt from his most recent book The Identity Trap, I was in.
To be honest, it was probably the class I put the least effort into that semester, only doing a couple of the readings each week, and triaging time for other courses on my schedule. That’s no reflection on the course or the professor, I just focused more on courses that were more related to my professional life. Yet, of all the classes I’ve taken on subjects ranging from international economics to strategy, policy, and IR theory, this is the one I keep coming back to in conversations. What I learned in the course regarding the collapse of global fertility rates and the concept of inverted age pyramids isn’t just academic, it’s interesting, and it’s important. It’s a topic with profound consequences for America, and every society on Earth.
Total Fertility Rate: The Vital Statistic
At the center of the course was a deceptively simple number: total fertility rate (TFR). TFR refers to the average number of children a woman is expected to have over the course of her “reproductive years,” typically measured between the ages of 15 and 49. In modern developed societies, a TFR of 2.1 is necessary to keep the population stable over time, accounting for child mortality and other attrition.¹
But in most of the developed world today, fertility rates are well below this replacement threshold. Countries like South Korea and Japan have some of the lowest TFRs in the world—hovering around 0.8 and 1.3 respectively.² Even the United States has seen its TFR fall to historic lows, recently sitting around 1.6.³
How did we get here? And why does it matter?
From Population Bomb to Population Bust
To understand today’s demographic decline, we have to rewind to a very different kind of panic: the fear of overpopulation.
In 1968, Stanford biologist Paul Ehrlich published his book The Population Bomb, a dire warning that humanity was on the verge of ecological and social collapse due to runaway population growth. He had been shaken by a trip to India, where the scenes of crowding and poverty convinced him the world was headed toward famine and chaos unless birth rates were drastically curtailed. (His exact words were “unless the birth rate is brought into alignment with the death rate,” potentially opening the door for a Thanos-esque solution). The human race Ehrlich said, was destined to “breed itself into oblivion.”⁴
Ehrlich’s warnings sparked an immediate response. A global movement emerged to reduce fertility rates through education, access to contraception, and even state policy. Some speculate that China’s one-child policy—introduced in 1980—was influenced by the intellectual environment that Ehrlich helped shape.⁵
But Ehrlich’s predictions didn’t come true. The world population continued to grow, but not exponentially. Meanwhile, technology allowed production to keep pace, precluding scarcity. But then a funny thing happened. Birth rates began to fall faster than anyone expected—especially in wealthier nations. According to the United Nations' World Population Prospects 2022, the global population is now projected to peak at around 10.4 billion in the 2080s and then begin to decline by the end of the century.1 This long-term trend reflects sustained declines in fertility across nearly every region of the world. So what happened?
Why Fertility Collapsed
Total fertility rates have fallen sharply across the world over the past few decades. The reasons are complex, but most fall into three broad categories: the proliferation of contraception, expanded education for women, and economic pressures.
Contraception
In the late 1960s, access to reliable birth control was limited, even in many advanced economies. The first oral contraceptive pill had only recently been approved in the United States, and early access was often restricted by legal barriers tied to marital status or geography.⁶ In much of Europe, hormonal birth control remained tightly regulated through the 1970s. In the developing world, contraceptive access was even more constrained, leaving most women with few options to control their fertility.
That picture began to shift in the 1970s and 1980s. Governments, international agencies, and public health organizations began treating family planning as a development and human rights priority. This resulted in a rapid expansion of contraceptive technologies, from pills and intrauterine devices (IUDs) to injectables, implants, and condoms. Permanent surgical methods such as vasectomies and tubal ligations also became safer, more common, and more widely accepted across cultures.⁶
Today, modern contraceptives are available in most countries and integrated into national healthcare systems. Over-the-counter options, telehealth services, and public subsidies have further reduced barriers to access. The ability to delay or limit childbearing is now an expected part of adulthood in many societies. This revolution in reproductive control allowed people to approach fertility as a decision rather than a default outcome. As access to contraception spread, birth rates fell—especially in countries where economic and educational trends reinforced the desire for smaller families.
Education
One of the most robust findings in demographic research is the inverse relationship between female education and fertility. The longer a woman stays in school, the fewer children she is likely to have.8 This pattern holds across cultures, income levels, and continents. In countries where most girls receive only a primary education, fertility rates remain high. In countries where women complete secondary school or attend college, fertility rates decline significantly.
The reasons are both structural and psychological. Longer education delays the onset of key life events like marriage, labor force participation, and childbearing. Higher education also influences values and aspirations. Women with advanced degrees are more likely to prioritize careers, financial independence, and personal autonomy. These shifts don’t eliminate the desire for children, but they often reduce the number of children a woman feels is compatible with her goals.
Parenthood becomes especially costly in highly skilled professions such as medicine, law, or academia. Taking extended time off can result in lost promotions, lower lifetime earnings, and reduced retirement security. Many women reduce their hours, forgo promotions, or leave the workforce entirely—decisions that carry permanent financial penalties.
Cultural change has accompanied these trends. In many educated, urban settings, small families or voluntary childlessness are no longer viewed as unusual. Social expectations have shifted. The result is not a rejection of parenthood, but a reevaluation of its timing, scale, and meaning.
While expanded education is a triumph of development, it presents a challenge for societies hoping to reverse fertility decline. Raising birth rates will require policies that ease the tradeoffs between education, career, and family life—not attempts to roll back hard-won gains in gender equality.
Economics
In most developed economies today, it is no longer feasible for one income to support a family. Housing, healthcare, education, and childcare costs have outpaced wage growth in nearly every major urban center. As a result, dual-income households have become the norm out of necessity, not preference.
This economic reality has transformed parenthood into a financially consequential decision. Unlike earlier generations, young adults must weigh the desire to start a family against competing obligations: student loans, housing instability, insufficient parental leave, and the rising cost of raising children. In the United States, the average cost of raising one child to age 18 now exceeds $300,000 when adjusted for inflation.10
These pressures fall disproportionately on women. Even in households where both partners work full time, women still perform the majority of unpaid domestic labor. This “second shift” creates chronic time poverty, burnout, and long-term career disadvantages.⁶ With each additional child, the burden grows heavier. Many dual-income households also face high housing costs, long work hours, and rising childcare expenses—all of which discourage large families. Women often absorb the burden of balancing paid work with unpaid caregiving, which further reduces the appeal of having more children.11
A particular pain point is childcare. In much of the United States and Western Europe, full-time daycare is prohibitively expensive. In many cities, it rivals the cost of rent or a mortgage. Government subsidies and public childcare programs often fall short, and waitlists for quality care can stretch for years. For families without extended kin networks or flexible employers, the lack of affordable childcare becomes an insurmountable barrier to expanding their family.
Workplace norms also reinforce this dynamic. In cultures where long hours and constant availability are rewarded, the demands of childrearing collide with the path to advancement. Limited paid leave, inflexible schedules, and weak labor protections all contribute to an environment where having children is penalized rather than supported.
As a result, many couples limit themselves to one or two children. This is not due to a lack of interest in family life, but rather a sober assessment of what they can afford and sustain. In the absence of serious structural reform, smaller families are not just common—they are rational.
The Inverted Pyramid
At first glance, this might not seem like a problem. Fewer people means fewer emissions, right? But demographers warn that sustained below-replacement fertility leads to something called an inverted population pyramid. This is a dangerous demographic shift with severe implications.
Imagine a traditional pyramid, with the widest part representing the youngest members of society and the tip representing the elderly. Now invert it. The elderly become the largest group, and the working-age population becomes a narrow neck supporting the weight above it.
This leads to three urgent problems:
Demographic Consequences of Fertility Collapse
Fertility decline is not just a personal or cultural phenomenon. When it becomes widespread and sustained, it reshapes the foundations of national economies, governance, and defense. The transition from a young, growing population to an older, shrinking one introduces deep structural challenges. These challenges fall most urgently into three domains: public finance, labor supply, and national security.
Fiscal Strain
Modern welfare states are built on the assumption of a broad and growing base of working-age taxpayers who contribute to public systems that support the elderly, the sick, and the unemployed. This model becomes unsustainable when demographic momentum reverses. As birth rates fall and life expectancy rises, the number of retirees increases while the number of workers shrinks. Fewer contributors must carry the cost of supporting more recipients.
In many countries, public pension systems are already under severe strain. Nations like Japan, Italy, and Germany are seeing old-age dependency ratios reach historic highs, meaning fewer workers are available to support each retiree.14 The solvency of national pension programs, including Social Security in the United States, is increasingly uncertain.13 Healthcare costs are also ballooning, as older populations require more frequent and more expensive medical care. Without major structural reform, countries may face rising deficits, higher taxes, and painful service cuts just to maintain fiscal balance.
Labor Shortage
Free-market economies depend on a steady supply of labor to maintain productivity, innovation, and competitiveness. Fertility collapse undermines that foundation. When fewer young people enter the workforce, businesses struggle to fill roles, especially in sectors that require physical labor, interpersonal service, or technical training.
Countries already experiencing population decline, such as South Korea and Italy, report severe shortages in areas like eldercare, agriculture, construction, and manufacturing.14 These gaps reduce overall economic output, raise wage pressures, and in some cases force businesses to close or relocate. While automation and artificial intelligence can offset certain forms of labor scarcity, they cannot fully replace the human workforce—particularly in caregiving, teaching, law enforcement, and service roles that require emotional intelligence, dexterity, or cultural context.
The broader macroeconomic consequences are significant. Declining working-age populations slow GDP growth, suppress consumer demand, and undermine the tax base.15 Long-term stagnation or contraction becomes a looming risk, particularly in countries that resist immigration or fail to incentivize workforce participation among underrepresented groups.
National Security
Perhaps the most underappreciated consequence of demographic decline is its impact on national defense. A country’s ability to field and sustain a capable military force depends on having a sufficient pool of healthy, working-age adults. As youth cohorts shrink, recruitment becomes more difficult. Militaries must either lower standards, increase compensation, or reduce force size. In some countries, all three are occurring at once.
The United States, for example, has faced persistent shortfalls in military recruiting in recent years, despite increased bonuses and marketing efforts.16 This problem is even more acute in countries with smaller populations and mandatory service systems. A diminished youth population not only undermines military readiness but also limits a society’s ability to scale up quickly in response to a major conflict.
Beyond personnel, aging societies often shift political priorities away from defense and toward social spending. Older electorates tend to favor investment in healthcare and pensions over military expansion, potentially weakening deterrence postures over time.12 In a geopolitical environment defined by renewed great power rivalry, demographic resilience is becoming an increasingly important component of national power.
A Smarter Path Forward
In recent decades, many governments have attempted to reverse fertility decline through a variety of pro-natalist policies. These typically include direct cash payments, tax incentives, subsidized childcare, and generous parental leave. France, for example, has long offered robust family support, including universal preschool and monthly allowances for children. Hungary recently launched a multi-pronged initiative that includes zero-interest loans for married couples and debt forgiveness for women who have three or more children.21
Despite these efforts, no country has yet succeeded in sustainably raising its total fertility rate (TFR) back above the replacement level of 2.1. Most hover between 1.3 and 1.7, even after substantial public investment.⁸ The failure of these policies is not due to a lack of effort or funding, but rather a misunderstanding of the structural and psychological costs associated with modern childrearing. The decision to have a child is shaped by deep concerns about housing, work-life balance, education, and long-term stability—concerns that cannot be erased with cash bonuses or temporary subsidies.
Another limitation of most pro-natalist strategies is that they are aimed at the wrong audience. Governments often focus on persuading childless couples to start families, even though this group tends to be more ambivalent or hesitant about parenting. A more promising approach may lie in encouraging those who already have one or two children to consider having a third.
Focus on Families with One or Two Children
Families who already have children typically have the logistical and emotional infrastructure in place: a home with multiple bedrooms, a vehicle that fits car seats, and some lived experience with parenting. These households may be more responsive to incentives such as housing support, expanded child tax credits, or tuition relief for third or fourth children. Research from South Korea suggests that while financial incentives have limited impact on first-birth decisions, they are more effective in nudging families toward additional children.20
Policy could also be tailored to address known barriers to larger families, such as the high cost of extracurriculars, inadequate maternity leave after a second child, or the challenge of reentering the workforce after a career break. By acknowledging the realities of family economics and offering support that scales with family size, governments may be able to achieve modest but meaningful gains in fertility.
Rethink the Family Unit
Beyond financial incentives, there is room to rethink how we define and support families. In the twenty-first century, the traditional nuclear model—married heterosexual couples with children—is no longer the norm for many. Rising divorce rates, delayed marriage, and growing acceptance of non-traditional relationships have created a gap between family policy and lived reality.
One radical idea worth exploring is the legal recognition of “co-parenting partnerships.” These could be formal arrangements between two or more adults who wish to raise a child together without being in a romantic relationship. For example, two longtime friends—gay, straight, or otherwise—might decide to co-parent, sharing legal and financial responsibilities. In the current legal framework, these arrangements often fall into a gray area, lacking the protections and benefits afforded to married couples.
Creating a co-parenting legal category could offer tax advantages, shared health coverage, or co-ownership protections similar to those granted through marriage. It would give people who desire children but not traditional marriage a viable legal structure in which to build a family. While this would represent a significant cultural shift, it may also align policy more closely with the evolving nature of family formation.
Immigration as Demographic Strategy
While adjusting fertility policy is important, the most immediate and powerful lever to address demographic imbalance is immigration. Many countries with declining populations face shrinking workforces and aging tax bases, while at the same time, regions like sub-Saharan Africa and parts of South Asia continue to see TFRs well above 4.0.18 These regions also face youth unemployment and infrastructure strain, creating an opportunity for mutually beneficial migration.
Rather than relying on unstructured immigration or reactive asylum systems, countries could create targeted migration programs that address labor shortages and demographic needs. This might include establishing regional talent and training centers in high-fertility countries to identify and prepare young adults for immigration. These centers could offer instruction in the destination country's language, vocational training for in-demand fields, and cultural orientation to ease integration.
Canada’s points-based immigration system and Germany’s dual vocational training model offer examples of structured immigration that align demographic strategy with national economic goals.¹9 Properly managed immigration can immediately increase the working-age population, diversify economies, and stabilize dependency ratios. It also provides a humane and productive outlet for population pressures in sending countries.
Immigration alone will not reverse demographic decline, but it can buy time and soften the most severe effects while governments develop long-term strategies to support family formation at home. Rather than seeing immigration as a cultural or political liability, policymakers should treat it as a necessary demographic tool—and one that can be made more efficient, humane, and strategic.
The Final Countdown
Demographics may not grab headlines. But they shape everything else. The world didn’t “breed itself into oblivion” as Paul Ehrlich feared. Instead, we’re quietly dwindling. And unless we act creatively, the consequences will cascade across our economies, our social support systems, and our ability to defend the nation.
Endnotes
United Nations Department of Economic and Social Affairs, World Population Prospects 2022 (New York: UN, 2022), https://population.un.org/wpp/.
World Bank, “Fertility Rate, Total (Births per Woman) – Korea, Rep.,” https://data.worldbank.org/indicator/SP.DYN.TFRT.IN.
Centers for Disease Control and Prevention (CDC), “Births: Final Data for 2023,” National Vital Statistics Reports 72, no. 1.
Paul Ehrlich, The Population Bomb (New York: Ballantine Books, 1968).
Susan Greenhalgh, “Science, Modernity, and the Making of China’s One-Child Policy,” Population and Development Review 29, no. 2 (2003): 163–196.
Andrea Tone, Devices and Desires: A History of Contraceptives in America (New York: Hill and Wang, 2001).
John Cleland et al., “Family Planning: The Unfinished Agenda,” The Lancet 368, no. 9549 (2006): 1810–27.
Wolfgang Lutz and Samir KC, “Global Human Capital: Integrating Education and Population,” Science 333, no. 6042 (2011): 587–92.
Claudia Goldin, Career and Family: Women’s Century-Long Journey toward Equity (Princeton: Princeton University Press, 2021).
Mark Lino, Expenditures on Children by Families, 2015 (Washington, DC: U.S. Department of Agriculture, 2017).
Arlie Hochschild and Anne Machung, The Second Shift: Working Families and the Revolution at Home, rev. ed. (New York: Penguin Books, 2012).
Organisation for Economic Co-operation and Development (OECD), Pensions at a Glance 2023: OECD and G20 Indicators (Paris: OECD Publishing, 2023), https://www.oecd.org/publications/pensions-at-a-glance-19991363.htm.
Congressional Budget Office, The 2023 Long-Term Budget Outlook (Washington, DC: CBO, June 2023), https://www.cbo.gov/publication/59096.
United Nations Department of Economic and Social Affairs, World Social Report 2023: Leaving No One Behind in an Ageing World (New York: UN, 2023), https://www.un.org/development/desa/dspd/world-social-report/2023.html.
Christine Lagarde, “Demographics and the Future of Growth,” speech at the Global Population Aging Conference, Beijing, November 1, 2015, https://www.imf.org/en/News/Articles/2015/09/28/04/53/sp110115.
U.S. Department of Defense, Fiscal Year 2023 Annual Report on Recruiting and Retention (Washington, DC: Office of the Under Secretary of Defense for Personnel and Readiness, 2024), https://prhome.defense.gov/.
Lyman Stone, “Natalism and the New Politics of Population,” The Public Discourse, March 3, 2020, https://www.thepublicdiscourse.com/2020/03/60763/.
United Nations Population Fund, “Fertility Rate High in Sub-Saharan Africa,” https://www.unfpa.org/data/world-population-dashboard.
Migration Policy Institute, “Points-Based Immigration Systems: Canada and Beyond,” Policy Brief, July 2019, https://www.migrationpolicy.org/research/points-based-immigration-systems-canada.
Sang-Hyop Lee and Kyeong-Hun Kim, “Impacts of Childbirth Subsidy on Fertility in Korea,” paper presented at the 2013 IUSSP Conference, Busan, South Korea, August 26–31. https://iussp.org/sites/default/files/event_call_for_papers/130617_Long_Abstract.pdf.
Euronews. “Hungary Offers €30,000 to Married Couples Who Can Produce Three Children.” Euronews, July 29, 2019. https://www.euronews.com/2019/07/29/hungary-offers-30-000-to-married-couples-who-can-produce-three-children.