Comment by geocon

That would be a terrible idea, frankly, because it will cause gradients of overbuilding/land abandonment and underuse. Think about it this way: you have a city where land is worth $30/sqft/yr in the center, $10 at the edge and $20 in between. If you set the tax at $20/sqft/yr, you will not incentivize people to build enough in the center of the city. It will be just fine in the middle, but it would be impossible to earn enough money from land to pay the tax on the outside of the city, so people would just abandon the land or try to build way more than you would actually want there (in which case the supposed land tax is actually cutting in and taxing labor and property as well)