Federal government gave billions of incentives to states to build more houses who in turn enacted higher density zoning and overrode the concerns of municipalities. And suddenly we have lots of houses being built.
Less immigrants makes the house situation better but not does not solve the problem. Having a continuous system for building lots of houses does.
Canada did this with a housing accelerator fund, for municipalities. Did not amount to much of anything. It's not clear if provinces can override but there's no political will for it. Without reading the numbers for Australia, I expect reform has been modest.
> Less immigrants makes the house situation better but not does not solve the problem.
You contradict yourself in the same sentence. The same result can be achieved whether improving elasticity or reducing the immigration rate. "the problem" is the affordability, not the elasticity. That is your just preferred vector.
Even if zoning is improved, you can't defy the laws of physics; housing will still be relatively inelastic, whereas immigration rate can be much higher.
Australia's population growth rate was less than 1% last year, basically on par with US. Canada's was 3%. Incomparable. No amount of zoning reform will be enough to handle that sustainably.
I'm all for the YIMBY and zoning reform push, but a) that's decided on the municipal level, b) change is slow, c) immigration rates can drastically change in very little time, if the feds decide. In Canada feds wanted to have their cake and eat it too: the population grew by over 3% in a year, but infrastructure at the provincial level (e.g. healthcare) didn't budge, and housing isn't building much faster than it was before.
If we understand that the issue with housing is inelasticity of supply, then it should be easy to surmise that other things can be inelastic: policy and the law. By contrast, immigration rate might as well be a push of a button.