Fertility is declining across the world and the phenomenon will increase. By 2050, three-quarters of the world's countries will have insufficient fertility rate to maintain their population as it is.
By 2100, most countries will be affected. Researchers also predict that the population of poor countries will continue to increase for a long time, particularly in sub-Saharan Africa, while it will decline in developed countries. This imbalance risks, according to them, having “considerable consequences on the economic and societal levels”