[ska]

There is a lot of research on this you can follow up on but short story on your first two points is a) a combination of old stock sales and rezoning is pricing existing residents out of neighborhoods, and b) the money isn't effective as stimulus, it's "parked". Besides the fact that "trickle down" theory has proven a failure at this point, there is no local value to a non-resident whose economic activity is done elsewhere not living in housing that is also not rented.

I think your last point is clearly true also, but the balance isn't obvious.

[eisbaar]

Research in that area is unfortunately very politically loaded. I don't think simply claiming "there is a lot of research" in such a politically disputed subject is sufficient.

As for b), if a Chinese investor buys some house from a Canadian, why is the money parked?

Trickle down or not, it seems in general if you can sell something (in this case houses to Chinese people), it is good.

If you build houses to sell to Chinese people, you also employ people from the building industry, for example. I'm not convinced that "trickle down theory" is the correct theory to apply there.

Special issues presumably arises with land and housing as a good - you shouldn't simply sell all your land to some foreign powers, presumably. Still, in general it holds.

If you worry about land area, you could build a huge skyscraper in a corner of the town that doesn't disturb too many people, and sell the flats to Chinese investors. Very little land use, huge margins.