[mapt]

Vacancy taxes are, to my understanding, nearly impossible to administer effectively without approaching them formally as normal property taxes that have some kind of out. Lying about when the unit got vacated is basically expected, while creating a new resident out of whole cloth and filing taxes for them including a Residency Benefit Transfer is a bunch of easy to detect felonies†, and understood as such by everyone. Spend the money on better schools/roads/park and even this isn't practical.

†Modulo accomodations for undocumented immigrants