Earlier quoted context omitted.
In Canada, second houses and vacant houses are taxed higher than primary residences.
As far as I know, they're taxed higher in the sense that they're not exempt from capital gains, like primary residences are, but in my view it seems like that would at-most be a marginal disincentive if renters don't have much in the way of other options or protections (which vary across the country). Likewise, I'm fairly sure a mom+pop residential landlord can save on tax for any expenses related to secondary suites…
The result is that in the last couple of years landlords have gotten rid of many rental units. This primarily affected smaller apartments, and surprise surprise, those prices have remained flat while the rest has increased.
On the other hand, sucks if you for some reason need to rent, because now there's just a few rental units out there and they're now expensive.