If we want evidence as to how rapid and widespread the demographic winter of falling fertility rates is, then look no further than this newly released study in the Lancet which is making headlines around the world. The study followed fertility trends in every country from 1950 until 2017. It sought to document the total fertility rates (or TFR, the number of children a woman will have in her life on average in a given population) of individual countries and the world as a whole. Generally a TFR of 2.1 is considered the minimum necessary for a population to reproduce itself from generation to generation. (This 2.1 represents a child for each parent and a bit extra since not all children born survive into adulthood and there are slightly more males born than females. In countries with a higher childhood mortality rate, the replacement TFR is higher than 2.1.) The results of the report are said to be “remarkable” and have come as a “huge surprise” to the researchers themselves.

First, globally the TFR has declined by half since 1950. Then, each woman in the world would have on average 4.7 children in their lifetimes. In 2017, that number had dropped to 2.4 children per woman, only a bit above the replacement level of 2.1 for developed countries. But it is at the level of individual nations that the real surprises can be seen. In 1950, no country had a TFR below the replacement rate of 2.1. That meant that every nation was naturally growing its population. Fast forward to 2017 and nearly half of the 200 odd countries of the world have a TFR of below 2.1. That is, nearly half the countries of the world have a population that will shrink once this generation dies out unless they rely on immigration to prop up their population numbers. But of course, as more countries fall into the “baby bust” territory of below 2.1 then there are fewer countries to supply these immigrants.

The findings are so dramatic that Prof Christopher Murray, the director of the Institute for Health Metrics and Evaluation at the University of Washington, said:

“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…We will soon be transitioning to a point where societies are grappling with a declining population.”

The countries with the lowest TFRs are in Europe and East Asia. The countries with the lowest TFRs are Cyprus and Taiwan with each woman in those countries only having one child in her lifetime. South Korean and Taiwan are just behind at 1.2 while Poland and Japan have a TFR of 1.3. At the other end of the scale, the countries with the ten highest TFRs in the world are all from Africa, with the exception of Afghanistan. Niger leads the way with a TFR of 7.1 while Mali, Chad and Somalia are all at 6 or over. China, still the world’s largest nation although India is catching up, has a TFR of 1.5. This is far below the replacement rate of 2.1, but actually China needs more than 2.1 to maintain a stable population naturally, since the report notes that 117 boys are born for every 100 girls in that country. This is the stark reality of the gendercide that has gone in that country due to sex-selective abortion and female infanticide.

So what are the practical implications of the study’s findings? Dr George Leeson, director of the Oxford Institute of Population Ageing told the BBC that:

“Demography impacts on every single aspect of our lives, just look out of your window at the people on the streets, the houses, the traffic, the consumption…Everything we plan for is not just driven by the numbers in the population, but also the age structure and that is changing, so fundamentally we haven’t got our heads around it.”

Murray notes:

“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. Think of all the profound social and economic consequences of a society structured like that with more grandparents than grandchildren.”

If demography is destiny, then the destiny of half the countries in the world is of decline. Will the next report into global fertility rates in a couple of decades show the trend towards sub-replacement TFR continue? Or have reached the bottom of fertility rate decline? Will Africa continue to buck the population trend? Or will it too join the rest of us in a low fertility future?