A recent study published in The Lancet reveals that by 2100, 97% of countries will experience a reduction in fertility rates. This analysis highlights a concerning trend: over the past 70 years, the global birth rate has decreased to less than half of its previous level.
By 2050, more than three-quarters of countries are projected to fall below fertility rates sufficient to sustain population growth. This proportion will rise to 97% by the century’s end. These projections point to a significant global demographic challenge.
Conversely, low-income regions, particularly in western and eastern Sub-Saharan Africa, will continue to record high fertility rates, driving population growth in these areas. This demographic disparity will have profound implications for economies and societies worldwide, as the study underscores.
The research draws on estimates from the 2021 Global Burden of Diseases, Injuries, and Risk Factors Study (GBD), conducted by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington’s School of Medicine. These estimates provide insight into current and future trends in fertility and births at regional, national, and global levels.
To maintain generational replacement in the long term, countries need to sustain a total fertility rate (TFR) of 2.1 children per woman—a measure representing the average number of children born to a woman over her reproductive lifetime.
According to the study, the number of countries and territories with unsustainable fertility rates for population replacement will reach 198, representing 97% of all nations and territories globally. This suggests that populations in these areas are destined to decline unless measures such as effective immigration policies or parental support initiatives are implemented to counteract low fertility.
The study’s authors emphasize that these projections underscore the challenges faced by middle- and high-income countries in sustaining economic growth. With a shrinking workforce and increasing pressures on healthcare and social security systems due to aging populations, these countries confront significant obstacles.
The demographic contrast between high- and low-income nations is also striking. The study anticipates a major shift in the global pattern of live births, transitioning from higher-income to lower-income countries. In 2021, about 29% of babies were born in Sub-Saharan Africa. However, projections indicate that this figure will rise to over half (54%) of all global births, highlighting the urgency of improving access to contraception and female education in these regions.
Stein Emil Vollset, senior author of the study and a researcher at IHME, observes: “We are witnessing remarkable social changes throughout the 21st century. The world will simultaneously face a ‘baby boom’ in some countries and a ‘baby bust’ in others.” This observation underscores the complexity and diversity of global demographic dynamics, necessitating adaptive and inclusive approaches to address these transformations.
“While much of the world faces serious challenges related to economic growth due to a shrinking workforce and aging populations, many resource-limited countries in Sub-Saharan Africa are focused on supporting the world’s youngest and fastest-growing populations amid politically and economically unstable healthcare systems,” Vollset analyzes.
Natalia V. Bhattacharjee, co-author of the study and principal research scientist at IHME, adds that these future trends in fertility rates and live births “will completely reshape the global economy and international balance of power, requiring societies to reorganize.”
The study also highlights a global decline in fertility over the past decades. In 1950, the global total fertility rate was about five children per woman, decreasing to 2.2 children per woman in 2021. This trend is particularly alarming in countries such as South Korea and Serbia, where the rate is below 1.1 children.
Conversely, fertility rates remain high in Sub-Saharan Africa, with an average of four children per woman in 2021—nearly double the global average. Chad has the highest total fertility rate globally, with seven births per woman.
The analysis predicts a further global fertility decline, with a projected total fertility rate of approximately 1.8 in 2050 and 1.6 in 2100. By then, only six of 204 countries and territories (Samoa, Somalia, Tonga, Niger, Chad, and Tajikistan) are expected to maintain fertility rates above 2.1 births per woman. In 13 countries, including Bhutan, Bangladesh, Nepal, and Saudi Arabia, rates are expected to drop below one child per woman.
Additionally, most of the world is transitioning to a natural population decline, where deaths outnumber live births. By 2100, only 26 countries, including Angola, Zambia, and Uganda, are projected to maintain population growth, with births exceeding deaths.
“In many ways, the decline in fertility rates is a success story, reflecting not only better and more accessible contraception but also the postponement or reduction of childbirth by many women, along with increased educational and employment opportunities,” Vollset notes.
The study emphasizes the need to expand access to modern contraceptives and promote female education to accelerate fertility declines and reduce birth rates in high-fertility countries.
Furthermore, the study examined the impact of pro-natalist policies offering financial support and childcare assistance to families in an effort to increase fertility rates in low-fertility countries. Data from nations that have implemented such policies suggest these measures can prevent excessively low fertility rates in some regions.
Low birth rates pose numerous challenges for individuals and societies. With fewer children born, the proportion of elderly people in the population rises, placing pressure on healthcare, social security, and elder care services. An increasing number of older people relative to the economically active population can strain available resources and challenge the sustainability of social security programs.
Low fertility rates can also negatively affect consumption, investment, and long-term economic growth. With fewer children born, demand for goods and services related to childhood, such as education, daycare, and toys, diminishes.
