Tax on land values intended as the sole source of government revenues, replacing all existing taxes. Henry George proposed the single tax in his book Progress and Poverty (1879). The plan gained considerable support in subsequent decades but was never implemented. Advocates argued that since land is a fixed resource, the income it yields is a product of the economy's growth and not individual effort, and that it therefore can fairly be taxed to support the government. Critics protested that the single tax would take no account of an individual's ability to pay, since there is no correlation between land ownership and total wealth or income.