Kellisa

was born in the hospital's maternity section at 7.21pm last night, roughly the moment when the Bureau of Statistics believes the 21 million mark would be reached.

The census, held on August 6 last year, found evidence that Australia had almost 100,000 more people than originally believed.

The bureau estimates that in the past year alone, Australia's population grew by a record 300,000. Just over half that growth is coming from migration, which last year was the highest in almost 20 years, and is set to climb higher as employers hunt for skilled workers.

Last year almost 266,000 babies were born, the second highest ever. the death rate is now a third lower than it was 15 years ago.

This combination is rapidly changing Australia's horizons, and reawakening a population debate.

What would this do to our economy, and our environment? There's no evidence that size makes for economic success. The world's richest economy is Luxembourg.