Affordable housing crisis – I’m part of the problem

Here’s some quasi-scientific evidence of something I’ve noticed in Toronto.  I think there are a lot of people (like me) whose Toronto homes are often vacant.  It’s a sign of inequality of incomes/wealth.
My one-bedroom apartment in Toronto is vacant more than half the time.
The young family that lives next to me seems to be there only half the time.  They have a loud toddler. It’s easy to tell when they’re home. I’m guessing they’re using it as a pied-a-terre.
My granddaughter has a friend who lives near her school but whose family also has a home in Scarborough.
And this guy – the quasi-researcher, found lots of dark condos and concluded that they are owned but vacant.
https://www.thestar.com/news/gta/2019/11/10/how-many-condos-are-sitting-empty-in-toronto-one-man-investigated-and-what-he-found-surprised-him.html
I can’t think of what a good regulatory approach to this situation should be. The objective would be to redistribute the existing supply of housing in order to meet the needs of families who can’t afford adequate housing. Taxing perpetually vacant condos might work.  Taxing merely under-used condos and apartments would be hard to do and probably wouldn’t change behaviour much – just tick off people like me.
Public shaming would be effective. For example, change the rules for overnight parking so that occasional residents like me have to display a big parking permit in their windshield that says, “I’m partially responsible for the affordable housing crisis.”   That approach wouldn’t address the absentee condo owners.
Better would be incentives for people to rent out their living space when they’re not using (the government would subsidize AirBnB listings? That doesn’t sound right, but why not if it brings extra supply on to the market?)