Wild idea... Maybe tax wealth instead of income? Tax break on single home ownership, but significantly increased tax on multi-home-ownership? It would be interesting to see comparisons between PE ownership in markets with property tax vs markets without.
Wealth taxes don't work because wealth gets extremely fuzzy. For example, unsold stock that I bought 15 years ago; and then got a loan against. I'm wealthy... kinda? But I didn't sell the stock; I have unrealized gains, and you shouldn't tax me beyond income tax on borrowed money? Okay, tax me on my unrealized gains then - but then 2008 repeats itself, stock goes down 40%, do I get a refund? Of course not, I only pay…
We already do this for property taxes.