Canada

That release valve you speak of is unsustainable due to infrastructure and transportation costs. It only works up to some level of sprawl.

Completely agree. Greenbelt policies are necessary for environmental and infrastructure reasons, they just also cause problems from a housing affordability / market elasticity standpoint, which we haven't addressed at all.

Correct, which is why it has to be public investment. We need massive multi unit buildouts funded by new public spending. All of it durable, cheap affordable housing. This will not only act on prices via increasing supply, it will also act by bidding prices down because the prices will not be maximizing profits. Whoever wants a place to live, should be able to afford one of thes units. Let the market sort out prices and availability of more premium options.

I do generally agree with this approach, though I think that a) as long as units are up for private ownership, it will make sense for investors to buy them up and hold them, you do also need to pair this with both vacant property taxes and ban investors from buying government built housing.

And b) it also won't work if the government only builds out the bottom of the market. Like we're seeing right now with the condo market, if you just build shitty units that people don't actually want to live in, then people won't really consider them part of the same market and any effects their supply has won't spread widely. If the government actually builds out livable Habitat 67 style buildings and units that middle class people would want to live in then it will be most effective.