Except that is in cities like Toronto/Vancouver more condos doesn't mean more people living in those condos. These are investment vehicles. Many of these new condo biuldings in trendy neighbourhoods sit empty, having been purchased as an investment rather than as a living space. What is needed is more rental units, not more places for rich people to park money.
Vancouver is finding that difficult to enforce. How do you tell if a unit is "occupied" or not? At the moment it is largely voluntary. The city cannot tell whether someone is living in a unit or it living overseas ten months out of the year. They aren't going to be sending inspectors to knock on doors.
I'm a good example of the difficulties. I was away on training (military) for six months. My apparment sat empty. Should I have been paying the tax? How would the government detect that I wasn't there?... Short of me or my landlord admitting to it and then paying the tax.
Well, why not? Arguably they would pay for themselves in a short time if implemented correctly.
Combine that with criminal tax fraud charges for cheats.
Oh, They can't really get hold of Vlad Q Oligarch because he's sailing his 100M yacht somewhere in the carribeans?
Expropriate the property.
Drastic? Maybe. I don't think unreasonable, however, for people gaming the system and cheating on their tax obligations.
Edited to add: Of course there should be exceptions for inhabitants with a good reason not to live in their home for a certain amount of time. I.e military, guest professorships, etc
Someone being gone for a stint and leaving a single apartment unoccupied for a while might not be a big issue in the grand scheme of things, if most of the problem is from people who can afford several properties. If the city wanted to go after these sort of units, maybe they could pull utility data and see a drop off in use. I'm no plumber, but with Vancouver winters, maybe you do want to have your water service shut off if you will be gone long term? No one likes coming home to a house completely encased in ice inside and out.