I have seen this phrase “aging population” appear in the media for years, probably decades.

It’s confusing as it applies that we are somehow making more old people.

What they meant to say is – the average age of the population is getting older because the birth rate has fallen dramatically, first in the 1970s, rose a bit in the 1980s/early 1990s, and then fell below replacement level ever since.

We are not making more old people as the notion implies – it’s because we are not making more young people. Consequently, the average age of the entire population is moving up. And the percent of the population that is older is now larger than the percent of the population that is young – because of the post WW2 baby boom cohort was so big and is now getting one year old older, every year. Hence, the average age goes up.

Saying “aging population” does not make this clear.

This chart helps to see the issue clearly – the cohorts under about age 30 are becoming smaller and smaller.

Versus the 1960s when the average age was going down:

Coldstreams