I don't even remember the title, but it was written by Clive Cussler.
It was the dullest, most stereotypical adventure book with the bog standard protagonist and plot, with no interesting twist or unexpected event at all.
When PES came out and it seemed to do better that FIFA I looked it up and I was amazed to find out it was from the same publisher as the football game I loved in the early 2000 and nobody else played (ISS Pro)
You could probably sell it as an incentive thing. Rent your property, pay less property tax on it.
But I'd say the tax on rent should still be there, and be proportional to it. Since the property tax would also be dependent on the value of the property, what you say could still be true.
I'd imagine those would be separate taxes. One is a property tax because you own that property, and then if you earn money from it via short or long term rentals you pay taxes on that.
progressively higher property taxes for every additional one (probably with an upper limit)
restrictions and heavy taxes on short term rentals
any house that's not a permanent short term rental (with associated taxation) and has not been the object of a long term rental for some reasonable amount of time, gets forcibly put on the rental market at a government fixed rate
heavy fines for and seizure of properties intentionally left unoccupied to artificially inflate rents