[vacri]

> Given a population growth rate of about 2% per year, like it was in the 1960s, an average mass of 60 kg per person, current world population of 7 billion

Economic growth in developed countries is driven by population growth, and this is why they all have a decent amount of immigration, to sustain that growth. In developing countries, they can grow by development - adding more subsistence farmers doesn't really grow the economy.

Australia has just taken the record for the longest period without a recession (26ish years), and this has been done on the back of immigration - since 1999, we've increased our population by a quarter, and our birthrate is only replacement-level. Population growth in developed countries != population growth globally.

[daemin]

I'd say a lot of the growth has been by exporting dirt and food to China and other Asian countries. This made Australia resistant to the GFC crashes because our raw materials were in great demand. It was also regardless of immigration as other countries with similar levels of immigration did not have the same economic success.

[vacri]

Mining is only 7-8% of our economy. We survived both the GFC and the recent years of mining downturn. Mining isn't a small part of it, but it's not really the key player in our economy. Agriculture is much bigger, but still, the reason why we import so many humans[1] is to keep our economy growing. Immigration isn't the only thing that can affect an economy, but with an ageing population, bringing in new youthful blood helps keep the workforce growing.

[1] The only large Western nations with higher immigration rates are Spain and, surprisingly, Norway.

[klodolph]

> Population growth in developed countries != population growth globally.

Right, and both are unsustainable long-term.