Our resident Stats Guy explores the myriad tales a population pyramid can tell, as well as its drawbacks.

If you want to explore population data, if you think about demographics – it’s probably a population pyramid that you are intuitively visualising.

Today I will explain why population pyramids are great and why I nonetheless never, ever use them in my presentations.

It’s a simple enough graphic.

On one side are the blokes, on the other the sheilas, with age groups stacked from youngest at the bottom to oldest up top.

Sometimes the shading shows if there is a surplus of men or women for each year of age, as in this example of South Korea.

The shape of the population pyramid tells us plenty. A broad base? That means lots of kids, a sign of a young, growing community.

A bulge in the middle? You’re looking at a working-age boom. A top-heavy pyramid? That’s the mark of an ageing population, with more seniors than juniors.

Sometimes it’s the gaps that tell scary stories of wars or pandemics. A sudden surge in numbers? That’s a baby boom (if at the bottom of the pyramid) or a change in migration policy (if first occurring in the middle of the pyramid).

Interpreting a population pyramid is like reading a topographic map – the contours give you clues about the past, present, and even the future.

That’s why, whether you’re planning services or trying to project future market movements, this visual remains the go-to for anyone keen on making sense of population data.

Animating a population pyramid over decades allows us to see the........

© InDaily