Land is not a thing of human production

The way taxes raise prices is by increasing the cost of production and checking supply. But land is not a thing of human production, and taxes upon rent cannot check supply. Therefore, though a tax upon rent compels owners to pay more, it gives them no power to obtain more for the use of their land, as it in no way tends to reduce the supply of land. On the contrary, by compelling those who hold land for speculation to sell or let for what they can get, a tax on land values tends to increase the competition between owners, and thus to reduce the price of land. Henry George, Progress and Poverty, Book 8, Chapter 3.