The 20th century saw the greatest population surge in human history, rising globally from 1.6 billion in 1900 to 6 billion in 2000. That trend is over. The majority of demographic data suggest that, despite previous concerns about overpopulation crises, the bigger problem for most parts of the planet will be too few babies.
Data clearly reflects this phenomenon. In Japan, people buy more diapers for the elderly than babies. China, which long enforced a one-child policy, recently raised its child limit to three; the nation expects its population to peak and then decline in 2030. And the population growth rate in the U.S. is at historic lows, reminiscent of the Great Depression era.
A new study published in npj Urban Sustainability explores the future of underpopulation and how it’s likely to affect sustainability goals. Using demographic data from United Nations reports, the study argues that the underpopulation problem is dynamic and twofold: Populations are simultaneously shrinking and ageing.
“Globally, people above 65 years old are the fastest-growing segments of the population and in 2019, for the first time in human history, they outnumbered children younger than 5 years old,” the researchers wrote. “In 2020, 9% of the global population was above 65 years old, accounting for 728 million people. This population is projected to increase more than twofold, reaching 1.55 billion in 2050 and accounting to 16% of global population, at medium fertility rates.”
These changes won’t spread evenly across the globe. By 2050, the regions set to see the biggest increases in elderly populations include Europe, Asia, and North America, while most nations in Africa will continue to have a relatively young population.
Few weeks earlier, Tesla CEO Elon Musk said that declining birth rates present “the biggest danger civilization faces by far.” But it looks like it will be a few decades at least before population collapse will begin posing a problem.
The size and demographics of the population change when:
- fewer children are born;
- families with children move to larger towns and cities;
- young and better-educated people move to larger towns and cities.
The population of the EU-27 grew from 354.5 million in 1960 to 447.7 million in 2019. Yet, as regards live births, figures shrank from around 6.69 million in 1960 to 4.15 million in 2019. With about 3.54 million deaths in 1960, the natural population increased by nearly 3.15 million people that year. In contrast, the 4.65 million deaths in 2019 meant that the natural population declined by about 0.5 million that year.1 Eurostat’s baseline projections suggest that the EU-27 population will grow more slowly than in the past, peaking at 525 million persons in 2044, before declining to 416.1 million by 2100.2 According to United Nations data, the global population has risen dramatically – from 3.03 billion in 1960, to about 7.71 billion in 2019 – and is projected to rise further, passing 10 billion in 2057 to reach about 10.87 billion in 2100.3 Therefore, even when it was growing strongly, the EU-27 population represented an ever-shrinking proportion of the global population, down from 11.68 % in 1960 to 5.8 % in 2019, and is projected to be smaller still at just 4.35 % in 2057 and 3.83 % in 2100.
Population and development are intertwined in many ways, not all of them fully understood. Moreover, the effects of population growth may vary widely, depending on the institutional, economic, cultural, and demographic setting. Slow population growth itself requires new adjustments to support the growing burden of dependent elderly (see Box 5.7). The complexity of the subject makes it tempting to be agnostic about the consequences of rapid population growth. Nevertheless, the evidence discussed above points overwhelmingly to the conclusion that population growth at the rapid rates common in most of the developing world slows development. At the family level, as Chapter 4 showed, high fertility can reduce the amount of time and money devoted to each child’s development. It makes it harder to tackle poverty, because poor people tend to have large families, and because they benefit less from government spending on the programs they use most health and education, for example when public services cannot keep pace with population growth. At the societal level, as this chapter has emphasized, it weakens macroeconomic performance by making it more difficult to finance the investments in education and infrastructure that ensure sustained economic growth. Population growth eventually slows as parents decide to have fewer children. The factors behind parents’ decisions, discussed in the next chapter, then work their way through to benefit society as a whole. But it does not follow that slower population growth will be an immediate panacea for developing countries. Declines in fertility, for example, will cut the growth of the labour force only after fifteen to twenty years.
In the meantime, there are various non demographic measures by which countries can ease those development problems made more difficult by population growth. The adoption of trade and exchange rate policies that do not penalize labour and the dismantling of institutional barriers to creating jobs would ease the employment problem. Pricing policies in agriculture and more resources allocated to rural credit, agricultural research, and extension, and so forth, would increase agricultural output. In short, policies to reduce population growth can make an important contribution to development (especially in the long run), but their beneficial effects will be greatly diminished if they are not supported by the right macroeconomic and sectoral policies. At the same time, failure to address the population problem will itself reduce the set of macroeconomic and sectoral policies that are possible, and permanently foreclose some long-run development options.
Written by Kazi Ashraf