A newly published study has found that nearly half of countries have fertility rates which are below replacement level, meaning that population size will decrease without immigration.
Published in the November issue of The Lancet, the study examines population and fertility by age and sex in 195 countries and territories between 1950 and 2017.
Funded by the Bill & Melinda Gates Foundation and part of the Global Burden of Disease analysis, the study found that the total fertility rates have decreased by more than 49 percent. The study states women on average are having a fewer babies in their lifetime – 2.4 as of 2017, compared to 4.7 in 1950.
To maintain population, the total fertility reate needs to be about 2.1.
The world population has increased by nearly 200 percent since 1950, though researchers have expressed concern that fewer births will lead to more elderly people than children.
Professor Christopher Murray, the director of the Institute for Health Metrics and Evaluation at the University of Washington, told the BBC that half of the countries have birth rates which are lower than the replacement level.
“On current trends there will be very few children and lots of people over the age of 65 and that’s very difficult to sustain global society,” he said.
“Think of all the profound social and economic consequences of a society structured like that with more grandparents than grandchildren.”
“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 … the idea that it’s half the countries in the world will be a huge surprise to people.”
“We will soon be transitioning to a point where societies are grappling with a declining population.”
He said fertility rates are lower in more developed countries like the U.S., South Korea, Australia, and in much of Europe. However, due to higher life expectancies and immigration, the population in these countries have not decreased.
The study also found that three factors have contributed to the decline in fertility rates – more education and work for women, a decrease of deaths in babies under five, and increased availability of contraception.
When a trend in 2014 found a decrease in U.S. birth rates, experts identified the decrease as a shift in the cultural understanding about sex and childbearing, according to the National Catholic Register.
Mary Rice Hanson, who works at the Ethics and Public Policy Center, stated that “Our culture sees children through a warped lens, where children represent loss and burden – lost ‘freedom,’ lost privacy, lost wages, lost opportunities to travel, independence, even sex.”