[seoaeu]

I'm arguing that a 10x increase in property taxes (or whatever 100k/year works out to) would already be enough to trigger the current owner to sell.

Once the property is sold, a developer will find that their profit from constructing a building is roughly proportional to the floor area regardless of whether there is a 1% property tax or not. This is because the profit they earn per-sqft is more than the resulting net present value of future property taxes on it. Therefore they maximize the density as allowed under zoning and we end up with an efficient use of the land.

(Of course dumb zoning laws messes everything up, but that's a whole separate topic...)