That implies an added tax burden of $500/month per unit. It's only $500/month per lot if the lot is only expected to have one unit.
> New development isn't disincentivized — it's neutral or even encouraged under a pure LVT.
You're getting this result by comparing it to existing property tax, which even more heavily disincentivizes new development.
Consider what happens if you only compare LVT to itself, i.e. to see what happens if you raise the amount of LVT by $500/lot.
If you build the fourplex, the amount of LVT increases by $500/lot or $125/unit. Now incentive to build the fourplex is lost unless the tenants are going to eat another $125/mo in rent.
And wait a minute here, under the existing property tax system the government was getting $500/mo/unit in property tax. If the typical plot is going to have a fourplex on it and the tax is expected to raise the same amount of revenue as the old property tax then it needs to be $2000/lot and thereby likewise increase the required rents by $500/mo/unit.
Where the incentive changes is that now you'll want to build not just fourplexes but highrises to try to dilute the LVT over more units. But now you've got a weird incentive: If existing rents are high enough then you want to build a highrise. But as soon as they drop below the point that building a highrise is profitable -- and highrises have a higher construction cost per unit -- you certainly don't want to build anything smaller than that, because the higher LVT per unit for smaller structures outweighs the lower construction cost per unit for smaller structures. So as soon as prevailing rents can't justify any more highrises, you get no more construction at all. Even if there are still a bunch of abandoned lots.