If an absentee owner is forced to sell or rent, great! If a resident is forced to sell or rent, well, they'd be either selling to a wealthier, possibly absente

If an absentee owner is forced to sell or rent, great! If a resident is forced to sell or rent, well, they'd be either selling to a wealthier, possibly absentee owner who can afford the massive price and higher taxes, or they'd be renting a basement suite (since they're residents). Most basement suites legal to rent are already on the market, I think. There's a good chance that this would make the problem worse, by creating vacancies that nobody can afford to occupy. If it manages to crash the market, perhaps those people would be able to move back eventually or see their taxes drop in dollar terms, but it's not clearly a good thing.