This is specifically about Australia, but essentially all 3 parts of this piece (and related linked essays) sum up how to solve the housing crisis worldwide.

https://theemergentcity.substack.com/p/how-to-solve-housing-unaffordability

Boils down to:

1: change zoning laws to allow more multifamily construction

2: remove incentives for homeownership and generally disincentivize single family homes

3: build for density in ways that reinforce and support density

If you want more info, basically every mainstream economist in the world agrees this is the solution, and that this is a manufactured problem. It’s a result of regulatory capture by homeowners, essentially. There are many, many papers about it.

Here’s an easily-digestible article

https://www.businessinsider.com/economist-how-to-fix-america-housing-crisis-rural-cities-2022-10

And a well-cited study in an economic journal:

https://sites.lsa.umich.edu/mje/2022/12/30/the-economics-of-the-housing-shortage/

All these sources agree, because this is the solution. Realistically, the only bad solutions are subsidizing more demand via things like rent control - these will only make our problems worse, kind of like how adding more lanes to a highway doesn’t fix traffic.

SUPER high level, and slightly biased explanation: corporate home buying.

Large investment firms like buying up property increasing the demand and raising prices. This prices normal people out of being able to afford a house. It also raises other housing related costs like rent, because these firms want to make a profit. This in turn prices people out of being able to afford ANY housing.

When we’re just numbers on a spreadsheet, there is a certain level of vacancy and homelessness, that maximizes profits.