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Declining fertility rates are expected to trigger a transformative demographic shift over the next 25 years, with major implications for the global economy, according to a new study.
By 2050, three-quarters of countries are expected to fall below the population's replacement birth rate of 2.1 children per female, according to research published Wednesday in the Lancet medical journal.
This would make 49 countries – primarily located in low-income regions of sub-Saharan Africa and Asia – responsible for the majority of new births.
“Future trends in fertility rates and live births will propagate shifts in global population dynamics, leading to changes in international relations and the geopolitical environment, and highlighting new challenges in migration and global aid networks,” the report authors wrote in their conclusion.
By 2100, only six countries are expected to have birth rates that replace populations: the African countries of Chad, Niger and Tonga, the Pacific islands of Samoa and Tonga, and Tajikistan in Central Asia.
This changing demographic landscape will have “profound” social, economic, environmental and geopolitical impacts, the report’s authors said.
In particular, shrinking labor forces in advanced economies will require significant political and financial interventions, even as technological progress provides some support.
“As the labor force declines, the overall size of the economy will tend to decline even if output per worker remains the same. In the absence of liberal immigration policies, these countries will face many challenges,” said Dr. Christopher Murray, lead author of the report and director of the Institute for Health Metrics. And the review for CNBC.
“AI and robotics may reduce the economic impact of a declining workforce, but some sectors such as housing will still be severely affected,” he added.
Baby boom versus bust
The report, which was funded by the Bill and Melinda Gates Foundation, did not specify a specific figure for the specific economic impact of demographic shifts. However, it highlighted the disparity between high-income countries, where birth rates are steadily declining, and low-income countries, where birth rates continue to rise.
From 1950 to 2021, the global total fertility rate (TFR) – or the average number of children born to a woman – more than halved, falling from 4.84 to 2.23, as many countries became richer and women had fewer children. This trend has been exacerbated by societal transformations, such as increased female labor force participation, and political measures including China's one-child policy.
From 2050 to 2100, the global total fertility rate is expected to decline from 1.83 to 1.59. The replacement rate – or the number of children a couple needs to replace themselves – is 2.1 in most developed countries.
This comes despite the fact that the world population is expected to grow from the current 8 billion people to 9.7 billion by 2050, before reaching its peak of about 10.4 billion in the mid-1980s, according to the United Nations.
Indeed, many advanced economies have fertility rates well below the replacement rate. By mid-century, this category is set to include major economies such as China and India, with South Korea's birth rate ranking as the lowest in the world at 0.82.
Meanwhile, low-income countries are expected to see their share of new births nearly double from 18% in 2021 to 35% by 2100. By the turn of the century, sub-Saharan Africa will account for half of all new births, according to a new report. the report.
Murray said this could put poor countries in a “stronger position” to negotiate more ethical and fair migration policies — leverage that could become important as countries become increasingly vulnerable to the effects of climate change.
