[scotty79]

Don't you at least agree that if you'd replace a block of flats for thousand people with houses for 10 you'd seriously reduce supply of housing in this spot without affecting the demand much and so you'd increase the value and tax on each housing unit in this spot?

I'm no sure how land tax works in the US but in my country it is calculated by multiplying tax rate for given region by area of the plot and then divided between people who own the plot. Share is usually proportional to the area of the buildings or parts of them they own on this plot.