House Prices Are Out of Control, Why?, page-96

Low interest rates
Bigger more complex homes
Cheaper consumer goods (China imports)
Govt incentives/subsidies
Easier credit
Longer mortgage terms
Infrastructure direct costed to developers
Tight jobs market
Relaxation of speculation taxation
Negative gearing

If the states adhered to the original idea of the CSHA they signed up to post WW2, of slum clearance and no purchaser or tenant should be exploited, plus the promise of affordable state housing to counter developer and banker profiteering it might be a different picture. Shifting to a private landlord model instead of state based took the handcuffs off, giving financiers an open invitation to lend lend lend on their terms. IMO