Written by Olivia Nater | Published: March 5, 2026
While governments around the world are fretting over declining birthrates, experts are increasingly arguing that this fear is unwarranted and that low fertility may in fact bring economic benefits. Demographers Guillaume Marois and Wolfgang Lutz recently laid out this view in a letter published in the journal Nature Human Behaviour, while economist Adair Turner made the case in a Project Syndicate op-ed.
Fertility rates (the estimated number of births per woman over her lifetime) are declining across the world. Two-thirds of the world’s population now lives in countries that have a fertility rate below the “replacement” level of 2.1 — the average rate needed to maintain a population size in the absence of migration. However, just over a quarter of UN-recognized countries, states, and territories have shrinking populations — immigration and demographic momentum (built-in growth resulting from a large number of young people of reproductive age) often keep populations growing for many decades after fertility has dropped below replacement.
Despite the barrage of alarmist media stories leading readers to believe that our global population of 8.2 billion is about to drop off a cliff, it is actually on track to keep growing well into the second half of this century. The UN projects a global population peak of 10.3 billion in 2084, with no significant decline before 2100.
While most reasonable people recognize the environmental advantages of reduced population pressures, governments around the world are concerned about low fertility due to the widely held notion that continuous population growth is a prerequisite to a healthy economy, and that population aging and decline cause economic stagnation, due to a high proportion of elderly dependents and a shrinking pool of workers, consumers, and taxpayers.
Countries with low fertility have introduced a whole range of pronatalist policies aimed at increasing it. These generally range from financial incentives, such as baby cash bonuses and tax breaks, to more generous family policies, such as longer parental leave. Despite many billions spent on these efforts, they have largely been ineffective at significantly boosting the number of births. Data from across the globe show that once fertility drops below the replacement rate, it tends to stay there — a phenomenon known as the “low fertility trap.”
There are many good reasons people are having fewer babies, including affordability, concern over the state of the world, and most importantly, women’s increasing emancipation — you can explore these in our previous blog post.
Unfortunately, pronatalism has a dark side, with conservative and authoritarian governments attempting to restrict women’s rights and bodily autonomy, while promoting traditional, sexist gender roles.
Not everyone believes that low birthrates are economically harmful. In their correspondence paper, Guillaume Marois and Wolfgang Lutz — of the International Institute for Applied Systems Analysis (IIASA) and Wittgenstein Centre for Demography and Global Human Capital — argue that sub-replacement fertility could actually be economically and socially advantageous.
They state,
“The notion of ‘replacement-level fertility’ of about 2.1 children per woman is often presented as an ideal, as it leads to long-term stationarity in the absence of migration and constant mortality. However, this level does not necessarily maximize well-being per person. Smaller populations can maintain high living standards when labor force participation and productivity per worker increase.”
The authors point out that population structure, particularly the ratio of income generators to dependents, matters more than population size, and that better education is a key driver of productivity and innovation.
They claim,
“If lower fertility leads to more investments per child, higher productivity can more than compensate for the smaller number of future workers, particularly under rapid technological change.”
Economist and Co-chair of the Energy Transitions Commission, Adair Turner, makes the same argument in his op-ed. He notes that “rising dependency ratios are not a problem unless humanity has suddenly lost its ability to sustain productivity growth. In fact, AI is likely to strengthen it.”
Turner points out that productivity and GDP per capita have increased rapidly since the early 19th century despite the fact that people are now working much shorter hours than they used to. He explains that the rapid rise of AI will further increase productivity as well as automation, and says that it is absurd to fear both a shortage of workers and a shortage of jobs.
Sub-replacement fertility is economically desirable, argue Marois and Lutz, because available data show that this level maximizes per capita consumption:
“Moderately low fertility and population decline can raise living standards because capital is distributed among fewer workers, which increases capital per worker and productivity. Under this model, the fertility level that maximizes material well-being in high-income countries is typically well below the replacement level — often around 1.5 or even lower, depending on capital costs and intergenerational transfer patterns.”
Turner highlights that the standard measure of old-age dependency ignores the fact that babies are also dependents — lower fertility reduces child dependency even as old-age dependency increases:
“Politicians calling for ‘more babies’ should recognize that if birth rates do increase, the total dependency ratio will rise even faster than before until those children enter the workforce two decades later.”
Marois and Lutz offer an illustrative case study:
“A smaller number of children would reduce the youth dependency ratio for the next two decades without having an immediate effect on the old age dependency ratio. For China, projections show that under a very low fertility scenario (TFR = 0.8), the total dependency ratio remains lower than under a moderate scenario (TFR = 1.7) until around 2050. Although the age-based dependency gap widens thereafter as population aging accelerates, incorporating changes in educational attainment and labor force participation reveals that even under very low fertility, productivity-weighted dependency shows no major increase up to 2070.”
Governments seeking to boost birthrates tend to ignore the evidence that population growth can be economically (and socially) disadvantageous too. Turner notes:
“[T]here is no evidence that economies with sustained high fertility rates grow faster. On the contrary, persistently high fertility often leads to a demographic disaster of sluggish income growth and widespread unemployment.”
This is manifesting in sub-Saharan Africa, Turner writes, where rapid population growth goes hand-in-hand with extremely slow GDP growth and socioeconomic hardship:
“The region’s working-age population has risen from 206 million in 1990 to 580 million today. Rather than producing a demographic dividend, this population boom has fueled an underemployment crisis. The International Labor Organization estimates that 93% of Nigeria’s working-age population is either unemployed or stuck in the informal economy. […]
“Looking ahead, sub-Saharan Africa’s working-age population is projected to rise to 1.1 billion by 2050 and 1.9 billion by 2100. But in a world where most jobs can be automated, there is no chance that such vast numbers will be absorbed into high-productivity work. Africa will reap a true demographic dividend only when its fertility rates fall below replacement level.”
Turner also draws attention to the fact that population pressure often drives up cost of living, particularly housing costs, and that a shrinking workforce can lead to higher salaries.
As Marois, Lutz, and Turner demonstrate, low fertility is not something to fear because evidence shows that productivity and wellbeing can actually increase in the absence of population growth.
By investing in education, skills training, health, and parental and disability support, governments can maximize labor force participation and boost productivity and innovation even when populations decline.
Importantly, policymakers need to accept that they do not get to choose their countries’ fertility rates. As Turner writes:
“In a free society, fertility should not be determined by politicians or economists, but by individuals, particularly women. The key question, then, is what people themselves want, not what experts think the optimal rate might be.”
Journalists across the Global North are so fascinated by declining birthrates that this trend has become the dominant population-themed media narrative. Despite substantial published research on family size choices and…
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