Build-up · 6 cards
What changes before fertility falls?
Longer lives, cities, the internet: which usually comes before women have fewer children? Order in time does not prove a cause, but it rules out some simple explanations.
The cards, in order
- In 98% of countries fertility fell below 3 only after life expectancy passed 60
Longer lives: nearly always first.
- In 69% of countries fertility fell below 3 only after the urban share passed 50%
Cities: more often first, but far from always.
- In 88% of countries fertility fell below 2.1 before half the population went online
The internet: usually after.
- China: GDP per person grew 2.1-fold from 2010 to 2022, while births fell by 47%
One country where wealth, universities and the internet grew at once.
- Ethiopia: women have fewer children, yet 24% more babies are born than in 2010
Fewer children per woman, yet more births: two different counts.
- Two thirds of humanity lives where too few children are born to replace the generation
The result at world scale.
The internet came later
In 98% of countries fertility fell below 3 only after life expectancy passed 60; for cities the share is 69%. And in 88% of countries fertility fell below 2.1 before half the population went online. Order is not proof of a cause, but in most countries the internet arrived after fertility had already fallen.