In retrospect, the problem is the US has had poor property tax policies. Property tax should be based on 1) the land square footage and 2) the value of the location. If a lot is double the space of normal lot, the tax should be at least 50% higher. If the price increases sharply, the taxes should as well. This way large lots sizes and price fluctuations would stay in check. The property taxes in SF, by the way, are way too low for the current value and square footage of the lots.