Remember environmental activist Paul Ehrlich’s prediction in the 1960s that overpopulation would deplete the earth’s resources and drive millions to starvation? His Malthusian condemnation of humanity’s voracious appetite continues to dominate debates over the future of the planet, scaring young people away from even having children.
Ehrlich was wrong. But while we have come to believe that overpopulation will not kill us all, we are plagued by another demographic emergency. It’s not that we have too many children, it’s that we have too few children. This problem is real.
The most recent concern was government statistics released last week suggesting that the U.S. fertility rate – the number of children a woman has over her lifetime – is accelerating and could hit an all-time low of 1.57 by 2025. This is lower than the 1.62 predicted by the Congressional Budget Office (CBO) last January.
This is well below the 2.1 children per woman needed to maintain a stable population, a number not reached since the Great Recession of 2008. Although the population has not begun to decline, it is rapidly aging. This won’t keep us from going hungry, but it will further undermine America’s shaky foundations of social stability.
In 2000, there were approximately 24 Americans age 65 and older for every 100 working-age adults. By mid-century, that number will be 43, according to CBO. Taxes levied on a narrower group of working Americans are required to fund Medicare and Social Security for a growing class of pensioners, squeezing budget deficits and increasing debt.
CBO projects that spending on entitlements for the elderly will increase from 6% of GDP at the beginning of this century to 12.7% by 2055, largely due to an aging population. The CBO projects that the budget deficit, excluding debt interest, will reach about 2% of GDP by the 2040s. Economists at the Federal Reserve and Aspen Economic Strategy Group estimate that the United States could reach a surplus if the ratio of seniors to working-age people simply stabilized in 2025.
Birth rates are declining around the world
This is not just an American problem. Fertility rates are declining everywhere, both in rich countries with low birth rates and in poor countries with relatively high birth rates. Two-thirds of the world’s population lives in countries where birth rates are below replacement rates.
This is contributing to an increase in public debt, which the International Monetary Fund predicts will reach almost 94% of global GDP in 2025 and 100% by 2029, a year earlier than predicted in April 2025.
In China, where decades of policies that limit families to one child have resulted in one of the world’s lowest birth rates, the IMF predicts that an aging population will slow annual GDP growth by nearly 2 percentage points between 2024 and 2050, while pension spending will rise by nearly 10 percentage points of GDP. In developed OECD countries, aging is expected to increase pension and health spending by 3% of GDP.
This may not be particularly alarming to hardcore Ehrlichists who lurk in the environmental movement and hope that by controlling populations they can advance the fight against environmental distortions. Silicon Valley elites probably also welcome the happy coincidence that the working-age population is stalling just as AI is about to destroy human jobs.
However, declining birth rates cannot save the planet. Carbon emissions should fall significantly over the next 20 to 30 years. Populations don’t change that quickly. One study shows that even if global birth rates rose to the replacement rate of just over two children per woman, global temperatures in 2200 would rise by less than 0.1 degrees Celsius.
Proponents of population decline misunderstand how humanity has thrived through innovation despite environmental constraints. Just as agricultural innovations fed growing populations on limited land, the path to decarbonization requires large-scale zero-carbon energy production.
However, innovation requires people. A smaller population means fewer innovators. Smaller economies have fewer resources to pay for innovations with large upfront costs, and the market to justify these investments is smaller. It is no coincidence that the population mass created by the baby boom was accompanied by a surge in pharmaceutical innovations targeting the diseases of the boomer generation as the population ages.
Hopeful academics would like to believe that having more children is simply a matter of spending money. The decline in fertility rates in developed countries is largely due to the rising opportunity costs of childbearing for women, who must interrupt their education or careers to have children. But mounting evidence suggests that even societies that spend lavishly on public child care and family support to ease the burden do not consistently increase birth rates.
President Trump’s White House has some ideas. The plan is to deposit $1,000 into an account in Trump’s name for each child born during his term as president. Educating women about their menstrual cycles and making them more sexually available is emerging. To encourage patriotic women to continue doing so, she proposed the creation of a National Order of Motherhood.
But even if this caused a baby boom tomorrow, the world’s fiscal dilemma would not be resolved. It takes more than 20 years for children to start contributing economically. In the coming decades, their increase will increase the burden on national budgets.
What should I do? AI has the potential to strengthen the social contract by increasing economic growth through incredible productivity leaps and helping unemployed people, young and old. However, don’t rely on that. Given the plutocrats’ long-standing hostility to redistribution, getting the tech oligarchy to share in the spoils of the revolution may not be easy.
Despair has sparked fears that the demographic conundrum will provoke a gloomy response. In Children of Men, PD James’s zero-birth rate dystopia, the challenge of supporting the elderly is solved by encouraging their suicide. We know how to push older people into agreements that make their lives miserable by stripping them of Social Security and Medicare.
