Property taxes are assessed on land value + "improvements" (i.e., structures) value. A land value tax doesn't tax the imps. This generally encourages doing more productive things with the same parcel of land.
I think there's far too much wiggle room in the analysis of land-value vs improvement and would strongly prefer a solution that moves away from perpetual ownership and towards revolving leases instead. The way to do this non-coercively would be to gate the enormous tax benefits we bestow to real estate windfalls (1031 exchanges, the $500k exclusion, the 15% and 20% capital gains rates) behind conversion to a 99 year lease. We won't see the shade beneath those trees but our grandkids will.
This isn't really a problem in downtown Brooklyn or Austin, though.
I can't speak to Austin, but I would expect to see the same thing in the form of low-value land use. It happens whenever appreciation competes with or outstrips productive activity. Which is extremely common.
Investors should pay the collective for exclusive use of a scarce resource, they should not get paid for holding exclusive access to a scarce resource. That's bad and backwards. Unless you're an investor, of course ;)
Yes, but that's due to financing restrictions. Unless one is planning on putting a tax burden on every piece of real estate analogous to full leverage, the cost of financing an empty unit providing unsufficient motivation to fill it seems to imply a similarly-scaled LVT wouldn't either.
Again, I think that calculating LVT is highly problematic. If you ask me to defend it, I simply won't. Rolling leases are the way.
It isn't possible to calculate the tax with 100% accuracy, but that doesn't mean it is problematic to calculate with a close enough approximation. The process of multivariate analysis is relatively simple, relies upon public data, can be open sourced and is self correcting over time (with the addition of new data via sales).
It's also absolutely impossible to avoid. $0 needs to be spent on enforcement. You can't cart land off to a tax haven. If you don't pay you forfeit the land and property - simple. You don't need legions of forensic tax accountants to uncover a trail of transactions like you would for income taxes. You don't need arbitrary rules about where somebody's main residence is. You don't need elaborate machine learning models to detect VAT carousel fraud.
You need a bunch of publicly available data and a very simple model.
EDIT: I know I'm simplifying a bit. The actual tax laws might not be worded the way I described it, but the net effect is exactly this: you are taxed on the potential resale value of your land, which is highly dependent on "what's the most valuable thing that can be built here?" question.