Australia's demographic details will shock you: Almost half of us are foreigners, or their children

What is an Aussie anyway? Picture: Luke Marsden Source: News Limited

Nearly half of Australians alive today were either born overseas or have at least one parent who was, according to the last Census in 2011.

Yep, Australia is not the homogenous nation - of thongs, singlets and beer cans - we sometimes imagine ourselves to be.

And if we are, it's an adopted culture for most of us.

It seems we often need reminding that Australia is, in fact, one of the world's biggest - and most successful - melting pots of cultures.

In the United States, where Lady Liberty has been welcoming immigrants for centuries, only 13 per cent of Americans alive today were born overseas - half our percentage.

Even in the European Union, where proximity makes close bedfellows of different cultures, just 9 per cent of residents were born in foreign countries, from either within or outside the EU.

Mass immigration is a uniquely Australian characteristic and it has made us who we are today.

Yes, we have our tensions. We harbour the same deep-rooted scepticism towards outsiders that finds a home in all human hearts.

But, by and large, Australia today is a model multiculturalism, having successfully integrated generation after generation of people from the most far flung parts of the world.

In the early days of settlement, migrants came mostly from the UK and Europe.

But our citizenship ceremonies have become much more diverse of late.

In the decade from 2001 to 2011, the proportion of our overseas-born population who originate from Europe shrank from 52 per cent to just 40 per cent.

Meanwhile the proportion of foreign-born Australians who were born in Asia increased from 24 per cent to 33 per cent.

Between 2006 and 2011, the biggest growth came from India, with the number of Indian-born people living in Australian increasing by 148,261 people.

This was followed by China - with 112,379 more Chinese-born living in Australia - and New Zealand - an additional 93,934 Kiwis turned Aussies.

The proportion of migrants coming from countries outside of Europe and Asian also increased.

Regular waves of immigration are helping to keep us more youthful as a nation.

Australia's median age - if you lined everyone up in a row and selected the middle person - is 37 years.

But the median age of recent migrants - those who arrived between 2007 and the last census - was just 27.

While other ageing populations, like Japan, have resisted mass immigration putting them on a path to economic stagnation, Australia has maintained a fresh supply of willing hands.

And that's a good thing.

People often worry about immigrants stealing local jobs. But about 70 per cent of our immigration intake is of skilled workers. To the extent that migrants with specific skills fill jobs that could not otherwise be performed by existing Australians, they add to our economic prosperity.

And the income they earn they spend on goods and services produced by other Australians, creating even more jobs.

It's such a recipe for economic success that the Australian Industry Group recently lobbied the government to increase our annual migrant intake from 190,000 to 220,000.

The mining boom may be over, but there is still demand for workers on remote locations. Meanwhile, the growing housing boom in some parts of the country will also require construction workers.

The ageing of the population has already started to act as a drag on our economic potential.

The chief economist of HSBC Australia, Paul Bloxham, estimates our potential growth rate has shrunk to about 2.8 per cent a year, down from 3.5 per cent in the early 2000s, driven by weak productivity growth and a shrinking labour force due to ageing.

Less economic growth means a higher jobless rate as the economy stagnates, warns Bloxham.

Skilled foreign workers don't take away jobs, they help create the vibrant growing economy that creates them. Trying to protect local labour by curbing immigration only leads to economic stagnation.

In that way, Australia is fortunate to have the problem it has today - of many young foreigners wanting to make their home here. As populations age around the world, the competition for young migrants is only going to get fiercer.

So as we celebrate with a BBQ today, let's remember that strong immigration has always been the extra kindling on our economic fire.

Throw another dumpling on the barbie, would ya?