Global fertility rate falls below population replacement level for first time

A new study says the global fertility rate fell below the population replacement threshold in 2026, marking the first such decline on record, even outside periods of war or pandemic. The working paper, titled "Terra Incognita: The Economics of a Shrinking World," calculated that an average of 2.2 children per woman is needed to sustain the population. The researchers found the global fertility rate peaked in 1978 and has trended downward in 219 of 236 countries studied since 1950, with none showing an upward trajectory. The decline is most pronounced in low- and middle-income countries, according to the study. Fertility per woman stood at 0.87 in Thailand, 1.01 in Colombia, 1.35 in Iran, 1.52 in Brazil and 1.51 in Mexico as of 2025, while Tunisia recorded 1.45 using 2024 data. If current trends continue, the world's population is projected to keep growing for roughly 30 more years due to demographic momentum, peaking at around 9 billion in 2056 before beginning to fall. The researchers noted that the United Nations' central projection places the peak later, in 2084, at about 10.3 billion people.