The World Is Getting Older: Median Age by Country

From 22 in 1970 to about 31 today — and people over 65 now outnumber children under 5

The world's median age has risen from about 22 in 1970 to roughly 31 today, and it is still climbing. For the first time in history, people over 65 outnumber children under 5. That crossover happened around 2018 and is not going to reverse.

A 34-year spread

Median age — the age at which half a population is older and half younger — varies more between countries than almost any other demographic measure.

Japan and Monaco sit near 49. Italy, Germany, Portugal, and South Korea are all above 45. At the other extreme, Niger's median age is about 15, meaning half its population are children. Chad, Mali, and Uganda are all under 18.

These are not slight differences in national character. They are entirely different societies in terms of who needs schools, who needs pensions, who works, and who is cared for.

Ageing has two causes, and one is good news

Populations age for two reasons, and they are frequently confused.

1. People live longer. Rising life expectancy adds older people to the top of the age pyramid. This is unambiguously a success.
2. Fewer children are born. Falling fertility narrows the base. This is the larger effect by some distance.

That second point matters for how the problem is discussed. Ageing is driven more by the absence of births than by the presence of the elderly. A country can have modest life expectancy and still age rapidly if its birth rate collapses — which is roughly what happened in South Korea, now ageing faster than any country in recorded history.

The dependency ratio

The measure that carries real economic weight is the old-age dependency ratio: people 65 and over as a share of the working-age population (15–64).

In Japan there are now roughly two working-age people for every person over 65. In 1950 the figure was about twelve. Italy, Germany, and South Korea are on similar paths. The strain is arithmetic rather than ideological: pensions and health systems in most rich countries are funded largely by current workers, so a shrinking base of workers supporting a growing group of retirees puts pressure on the system regardless of how it is designed.

What countries actually do about it

Four responses, with honest track records:

• Raise the retirement age. Effective and widely adopted, but politically costly — it has triggered mass protests in France and elsewhere.
• Increase immigration. The fastest lever available, since it adds working-age people directly. Also the most politically contested.
• Raise birth rates. Attempted extensively; results are modest at best. No country that fell well below replacement has returned to it and stayed.
• Raise participation and productivity. Bringing more women and older workers into the workforce, plus automation. Real but incremental.

Most countries end up doing some of each, because no single lever is sufficient on its own.

It is arriving unevenly, and quickly

The important asymmetry is one of speed. France took roughly 150 years for its 65-plus share to rise from 7% to 14%. South Korea did it in about 18. China is compressing a similar transition into a few decades — and unlike Japan or Italy, it is doing so at a much lower level of income per person.

That is the phrase demographers use: getting old before getting rich. Wealthy countries built pension and healthcare systems while still young and growing. Countries ageing at speed today have less time to prepare and fewer resources to do it with.

Meanwhile sub-Saharan Africa remains young and will supply most of the world's population growth this century. See why birth rates are falling for the mechanism underneath all of this.