Our world is not sustainable. The foundation of civilization–human population itself–cannot be maintained in many nations around the world. Of the top twenty world economies1, none of them have enough children to sustain their population2. In many countries, the population pyramid is now a population obelisk. Africa is the only continent where a majority of the countries have a sustainable birth rate3, and the United Nations expects the world population to stop growing by the end of the century4. This low fertility rate is not primarily caused by economic factors, but rather a globalized culture that drives secularization, encourages adults not to have children, and fosters a child-unfriendly environment.
The first important question is how low fertility rates will affect the future. In the modern world, low fertility is often associated with high-income nations: every country in the G8 and European Union has below replacement fertility5. This continued economic prosperity can be attributed to many of these nations still having a stable or growing population due to a sufficiently young population or substantial immigration. While immigrants from high-fertility nations may be able to stave off population decline in high-income nations shortly, this model is not sustainable. By 2100, only six countries (Samoa, Somalia, Tonga, Niger, Chad, and Tajikistan) are expected to have above replacement total fertility rate, with none exceeding three children per woman6. Several studies found that population decline and stagnation have adverse effects on the economy. In the United States since the 1980s, researchers Michael Peters and Conor Walsh found that the lower population growth rate contributed significantly to a decrease in innovation and more market concentration. Although productivity increased in the short term, long term economic growth is likely to suffer7. With the continued decline in fertility, the economist Charles I. Jones predicts that the world may be heading toward an “Empty Planet” with a stagnant quality of life and perpetually declining population. Using a statistical model to estimate innovation and population growth, he estimates that the transmission of new ideas will decrease and eventually cease as the population declines8. Although the statistical models produced by researchers predict a sizeable possible range of outcomes, the vast majority agree that population decline harms the economy.
The next question to consider is what is causing the continued decrease in fertility. One commonly cited reason for this, at least in popular media, is the high cost of having children9. However, this claim is disputed by a study by researchers, such as Melissa Kearney, investigating the aftermath of the Great Recession in the United States. From the periods of 2004-2008 to 2015-2019, forty-nine of the fifty states (except North Dakota) saw a decline in the birth rate. Although a focus on the economic causes of the birth rate decline could explain why birth rates in the United States dipped immediately after the 2008 financial crisis, the continued decline puzzled economists. Researchers Kearney et al. attempted to understand which external factors and demographic groups drove the decline. Their analysis was from an economist's perspective, which relies on a simplified model of fertility decisions. The decision to have children is viewed as one of utility. To an economist, children benefit their parents in the same way as a house, a sports car, or a vacation.
Despite these seemingly reductive simplifications, this study still provides essential insights into the factors responsible for fertility decline. The researchers analyzed the changes in long-acting reversible contraceptive (LARC) use, childcare expenses, rental housing rates, female-male wage ratio, per capita student loan debt, and religiosity. Using regression analysis, they compared the changes in each of these variables to the changes in fertility. They found that none of the variables predicted the birth rate to any significant degree. LARC use and religiosity seemed to affect the birth rate in a way opposite to what one would expect, with more significant increase in LARC use and a decrease in religiosity being associated with a smaller fertility decline10. These surprising results raise many questions about why birth rates continue declining.
The actual cause of the fertility crisis is not a lack of ability to have children but rather a lack of desire to do so among adults in developed nations. A survey of American non-parents aged 18 to 49 found that 44% of adults did not believe they would ever have children. Of those, 56% said they did not want to have children. The following most cited reason, medical reasons, only garnered 19%11. Throwing aside the economic assumption of individualistic independent rational actors making fertility decisions through a purely utilitarian lens, the decision whether or not to have children is not made in a vacuum. The demographer Hans-Peter Kohler created a statistical model to predict how peer pressure affects individual fertility decisions. Using the model, he discovered that both high and low fertility periods tend to be influenced by dominant societal trends, creating a self-reinforcing effect. However, the model also predicted that spans of low fertility tend to last significantly longer than those of high fertility12. Historian Phillipe Ariès gives a qualitative anthropological account of the cultural shifts that led to decreased birth rates. With the rise of modernity, attitudes toward sexuality and childrearing changed from viewing them as uncontrollable natural forces to aspects that ought to be carefully planned. This cultural shift led to families desiring a lower quantity and a higher “quality” of children, allowing more resources to be devoted to each child. Surprisingly, Aries sees the modern-day shift away from childbearing as a return to the pre-modern conception of a parent-centered rather than child-centered family. The contemporary world is different, however, because the wide availability of birth control allows childbearing to be eliminated entirely13. Several researchers agree that social pressures and cultural attitudes toward children substantially impact the birth rate.
More evidence for a socio-cultural cause of birth rate decline comes from the differing fertility rates among American religious groups. Since the 1980s, American women who attend weekly religious services have had a total fertility rate that is consistently above or just below the replacement level of 2.1 children per woman. Meanwhile, in 2019, non-religious women had an ultra-low TFR of just 1.3 children per woman14. According to the Institute for Family Studies, “virtually 100% of the decline in fertility in the United States from 2012 to 2019 can be explained through a combination of a growing number of religious women converting to irreligion, and declining birth rates among the nonreligious.”15 There is also variation across different American religious groups. In 2014, all religious groups in the United States except mainline Protestants and Jews had above-replacement fertility. Historically, black Protestants and Mormons boasted the highest total fertility rates of 2.5 and 3.4 children, respectively16. The Mormons’ comparatively high fertility has been the subject of other studies as well. Researchers led by Thomas W.Draper compared the adult attachment ratings of adults in Utah County, Utah, to those in the rest of the country to determine if it had any effect on the birth rates. Adult attachment is a measurement of how strongly adults experience social bonds. The researchers found that adult attachment and birth rates were much higher in Utah County. This correlation could suggest that adults who feel stronger attachment bonds to those around them are more willing to start their own families. The researchers also suggest that the Mormon faith of the participants could have positively affected both fertility and attachment17. Therefore, religiosity remains an essential factor in predicting fertility rates among Americans.
One common counterargument to dispel concerns about population decline is that a reduced population will help the environment by reducing carbon emissions18. There is some basis for this claim. Researchers Seth Wynes and Kimberly A. Nicholas investigated which individual actions had the most significant effect on emission reduction. Some of the actions included having one fewer child, going car-free, not flying across the Atlantic Ocean one time, eating a plant-based diet, and recycling. The study found that “a US family who chooses to have one fewer child would provide the same level of emissions reductions as 684 teenagers who choose to adopt comprehensive recycling for the rest of their lives.”19 With fewer children being born, carbon emissions could be significantly affected. However, one issue with relying on a reduction in population to prevent climate change is that global population decline will not begin until the end of the twenty-first century20. Though decreased fertility may reduce population growth and make carbon emissions increase at a slower rate, population dynamics may not result in decreases in worldwide emissions for several decades. The innovation slowdown caused by the reduction in population growth21 could hamper effects curbing carbon emissions. A single new technology, such as carbon capture or solar panels, can reduce emissions significantly. Even technologies not directly related to green energy or carbon reduction can help address climate change. Through direct empirical analysis of Chinese provinces, researchers Sainan Cheng and Guohua Qu found that the digital economy reduced carbon emissions in urban areas.22 Therefore, although some environmentalists may welcome the decline in human population as a boon to the environment, its slow-acting effects and associated decrease in innovation prevent it from being a viable solution to climate change.
Now that the effects and causes of the fertility crisis have been examined, the final question to address is how the fertility crisis might be remedied. Some countries have attempted to reverse fertility decline. In Eastern Europe, researchers Linda J. Cook, Elena R. Iarskaia-Smirnova, and Vladimir A. Kozlov investigated the pro-natalist policies of Russia, Poland, and Hungary. These nations implemented a diverse range of incentives for having children. These included lump sums paid to mothers upon the birth or adoption of their first four children in Russia, monthly payments to families based on the number of children in Poland, and tax deductions for each child in Hungary.23 The researchers found that these initiatives managed to raise the birth rate in the short term but did not have any long-lasting effects on fertility, failing to prevent demographic decline.24 These results are somewhat unsurprising, due to the economic impacts on fertility being mostly negligible.25 Because fertility is largely affected by culture and religion, a shift towards more pro-natalist cultural values or a religious revival in the developed world could solve the fertility crisis. However, both revolutions seem quite unlikely in the modern cultural climate.
A smaller, more realistic approach is necessary instead. One possible solution could be to give young people, especially young men, more exposure to child rearing. Researchers Holger Von Der Lippe and Urs Fuhrer interviewed eastern German men in the early 2000s, when that area of the nation reached an unprecedentedly low fertility rate of 0.8 children per woman. They asked the men several questions related to family and child rearing. While some men wanted children and others did not, all of them agreed that they had little to no conception of what raising children would truly look like.26 Giving men more exposure to children through activities such as babysitting would give them a better idea of what having children means, and possibly encourage them to have more children. This greater exposure is a small-scale, achievable cultural shift that could raise the birth rate. Overall, economic solutions to the fertility crisis are inadequate, and cultural shifts, even small ones, may be more effective.
The fertility crisis is a serious and difficult issue to address. Fertility decline contributes to decreased population growth, which has negative effects on the economy, especially innovation. Economic factors do not significantly affect the birth rate, with economic improvements and monetary incentives failing to encourage adults to have larger families. Social and cultural values tend to have a much more significant effect on fertility. Small-scale efforts such as giving young men more childcare responsibilities could help address the birth rate crisis, but larger efforts are needed. Although a single person cannot change their culture, each person who decides to have a large family despite negative cultural pressures encourages the next person to do the same. Through individual and collective resistance, fertility decline can be reversed to create a more populous, connected, and sustainable world.
Endnotes
1 Central Intelligence Agency, The World Factbook: Real GDP (Purchasing Power Parity) (Washington, D.C.: Central Intelligence Agency, 2022).
2 Central Intelligence Agency, The World Factbook: Total Fertility Rate (Washington, D.C.: Central Intelligence Agency, 2023).
3 Central Intelligence Agency, Total Fertility Rate.
4 “Population,” United Nations, accessed April 17, 2024, https://www.un.org/en/global-issues/population.
5 Central Intelligence Agency, The World Factbook: Total Fertility Rate (Washington, DC: Central Intelligence Agency, 2023).
6 GBD 2021 Fertility and Forecasting Collaborators, “Global Fertility in 204 Countries and Territories, 1950–2021, with Forecasts to 2100: A Comprehensive Demographic
Analysis for the Global Burden of Disease Study 2021,” The Lancet (2024): 31.
7 Michael Peters and Conor Walsh, “Population Growth and Firm Dynamics,” unpublished manuscript (2021), 40.
8 Charles I. Jones, “The End of Economic Growth? Unintended Consequences of a Declining Population,” American Economic Review 112, no. 11 (2022): 3515.
9 For several examples, see the following: Claudia Canvan, “‘It’s Soul-destroying:’ Women Who Fear They Can't Afford Kids on What Needs to Change,” Women’s Health, last modified January 22, 2024, https://www.womenshealthmag.com/uk/health/a45116836/cant-afford-children/;
Katie Baskerville, “We Can't Afford To Have Kids–And No, Avocado On Toast Isn't
What Got Us Here,” HuffPost, last modified September 29, 2023, https://www.huffingtonpost.co.uk/entry/people-cannot-afford-to-have-kids-
anymore_uk_65143cebe4b0fa72d69d5ef2; Ammar Kalia, “‘It Is Devastating’: The Millennials Who Would Love to Have Kids–But Can’t Afford a Family,” The Guardian,
last modified October 13, 2021, https://www.theguardian.com/lifeandstyle/2021/oct/13/it-is-devastating-the-
millennials-who-would-love-to-have-kids-but-cant-afford-a-family.
10 Melissa Kearny, Phillip B. Levine, and Luke Pardue, “The Puzzle of Falling US Birth
Rates since the Great Recession,” Journal of Economic Perspectives 36, no. 1 (2022):
151-76.
11 Anna Brown, “Growing Share of Childless Adults in U.S. Don’t Expect to Ever Have
Children,” Pew Research Center, last modified November 19, 2021, https://www.pewresearch.org/short-read/2021/11/19/growing-share-of-childless-
adults-in-u-s-dont-expect-to-ever-have-children/
12 Hans-Peter Kohler, “Social Interactions and Fluctuations in Birth Rates,” Population Studies 54, no. 2 (2000): 223-37.
13 Phillipe Ariès, “Two Successive Motivations for the Declining Birth Rate in the West,” Population and Development Review 6, no. 4 (1980): 645-50.
14 Lyman Stone, “America’s Growing Religious-Secular Fertility Divide,” Institute for Family Studies, last modified August 9, 2022, https://ifstudies.org/blog/americas-
growing-religious-secular-fertility-divide.
15 Stone, “America’s Growing Religious-Secular Fertility Divide.”
16 “Chapter 3: Demographic Profiles of Religious Groups,” Pew Research Center, last modified May 12, 2015, https://www.pewresearch.org/religion/2015/05/12/chapter-3-demographic-profiles-of-religious-groups/.
17 Thomas W. Draper, Thomas B. Holman, Whitney White, and Shannon Grady, “Adult Attachment and Declining Birthrates,” Psychological Reports 100, no. 1 (2007): 22.
18 For several examples of news articles arguing in favor of foregoing children for the environment, see the following: Damian Carrington, “Want to Fight Climate Change? Have Fewer Children,” The Guardian, last modified July 12, 2017, https://www.theguardian.com/environment/2017/jul/12/want-to-fight-climate-
change-have-fewer-children; Rachel Gillet, “7 Reasons People Shouldn't Have Children, According to Science,” Business Insider, last modified November 28, 2017,
https://www.businessinsider.com/why-people-should-not-have-children-2017-11; Anna Lee, “Opinion: Why I’m Not Going to Have Children,” CNN, last modified November 11, 2023, https://www.cnn.com/2023/11/11/opinions/not-having-children-lee/index.html.
19 Seth Wynes and Kimberly A. Nicholas, “The Climate Mitigation Gap: Education and Government Recommendations Miss the Most Effective Individual Actions,”
Environmental Research Letters 12, no. 7 (2017): 3.
20 “Population,” United Nations, last accessed April 17, 2024, https://www.un.org/en/global-issues/population.
21 As mentioned above in Michael Peters and Conor Walsh, “Population Growth and Firm Dynamics”; Jones, “The End of Economic Growth.”
22 Sainan Cheng and Guohua Qu, “Research on the Effect of Digital Economy on Carbon Emissions under the Background of “Double Carbon,”” International Journal of
Environmental Research and Public Health 20, no. 6 (2023): 22.
23 Linda J. Cook, Elena R. Iarskaia-Smirnova, and Vladimir A. Kozlov, “Trying to Reverse Demographic Decline: Pro-Natalist and Family Policies in Russia, Poland and
Hungary,” Social Policy and Society 22, no. 2 (2023): 359-61.
24 Cook, Iarskaia-Smirnova, and Kozlov, “Trying to Reverse Demographic Decline,” 371.
25 Kearny, Levine, and Pardue, “The Puzzle of Falling US Birth Rates,” 164-6.
26 Holger Von Der Lippe and Urs Fuhrer, “Where Qualitative Research Meets Demography: Interdisciplinary Explorations of Conceptions of Fatherhood in an Extremely Low Fertility Context,” Qualitative Research 4, no. 2 (2004): 201-26.
