How high does the fertility rate have to be?
Whenever a country’s average fertility rate drops below approximately 2.1 then populations will eventually start to shrink (this “baby bust” figure is significantly higher in countries which have high rates of death in childhood).
At the start of the study, in 1950, there were zero nations in this position.
Prof Christopher Murray, the director of the Institute for Health Metrics and Evaluation at the University of Washington, told the BBC: “We’ve reached this watershed where half of countries have fertility rates below the replacement level, so if nothing happens the populations will decline in those countries.”
“It’s a remarkable transition.”
“It’s a surprise even to people like myself, the idea that it’s half the countries in the world will be a huge surprise to people.”