Those 900 dollars don't just stay in everybody's bank account, they get spent, and start circulating the system and eventually consolidated into fewer hands, who in turn buys properties or other assets.
Yeah ok, I don't have anything to point to which refutes that.
An analysis of the breakdown of the contributors to the Australian housing bubble in 2018 would be cool to see, though. Probably some kind of even split between significant foreign investment in property, negative tax gearing, zoning laws, transport infrastructure issues and a one-off $900 payment that went to middle and low-income earners a decade ago.
Damned trickle-up economics.
900 dollars, or even $2100 for a small family isn't the sort of cash that would inflate an auction for a home anywhere, let alone in one of the australian cities affected by the current bubble.