Fertility rates in nearly all countries will be too low to sustain population levels by the end of the century, and most of the world’s live births will be occurring in poorer countries, according to a study published on Wednesday.
The trend will lead to a “baby boom” and “baby bust” divide across the world, with the boom concentrated in low-income countries that are more susceptible to economic and political instability, senior researcher Stein Emil Vollset from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington in Seattle said in a statement.
The study reported in The Lancet projects that 155 of 204 countries and territories worldwide, or 76 percent, will have fertility rates below population replacement levels by 2050. By 2100, that is expected to rise to 198, or 97 percent, researchers estimated.
The forecasts are based on surveys, censuses, and other sources of data collected from 1950 through 2021 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study.
Over three-quarters of live births will occur in low- and lower-middle-income countries by the end of the century, with more than half taking place in sub-Saharan Africa, researchers said.
The global fertility rate—the average number of births per woman—has fallen from around 5 children in 1950 to 2.2 in 2021, data show.
By 2021, 110 countries and territories (54 percent) had rates below the population replacement level of 2.1 children per woman.
The study highlights a particularly worrying trend for countries like South Korea and Serbia, where the fertility rate is less than 1.1 child per female, exposing them to the challenges of a dwindling workforce.
Many of the most resource-limited countries “will be grappling with how to support the youngest, fastest-growing population on the planet in some of the most politically and economically unstable, heat-stressed, and health system-strained places on earth,” Mr. Vollset said.
The authors noted that predictions were limited by the quantity and quality of past data, especially for the 2020–2021 COVID-19 pandemic period.
