Population growth is always an issue of intense debate, bouncing between a nation’s acceptance (and need) for migrants and an anti-foreigner sentiment. New Zealand and Australia are both typical and similar in this regard – both have relatively low populations for their size.

Until recently, I lived in Australia where one of the most heated political debates is about population growth. Ever since a 2009 government report projected that Australia’s population would rise from its current 22 million to 36 million by 2050, our neighbours on the West Island have been discussing the pros and cons of a ‘Big Australia’.

‘Big Australia’ is in fact a misnomer. Even at 36 million inhabitants, Australia would only be a mid-sized nation, roughly on par with Peru, Morocco and Poland. And it would still be one of the most sparsely populated countries on Earth with a population density of just 4.6 persons per square kilometre.

But the term ‘Big Australia’ is not the only absurdity in the debate. The weirdest thing is the discussion about whether Australia should grow at all – as if it was something they can freely chose.

The truth is that two out of three factors influencing the size of Australia’s population cannot be controlled by government, and the third factor is difficult to manage.

A population’s size is determined by life expectancy, fertility and migration. Australia has a young population that will likely live longer than their parents. It has a much healthier fertility rate than most other developed countries. Both are out of government control, positive, and set to increase Australia’s population.

This leaves the net migration intake. But who would cut the country’s humanitarian intake? Who would stop family reunions? Who would stop skilled migrants from entering the country? And since we are talking about the ‘net’ intake, who can stop Australians from emigrating or returning home?

All in all, the ways in which government can ‘fine tune’ Australia’s population are limited. Australians are debating the wrong question.

Building roads, rails, schools and houses may not be as intellectually stimulating as discussing population growth, but it is what Australians should really be doing instead of debating whether they want a bigger Australia.