Roy Davidson, commenting on Liggio's review of Howe and Morgan, says that "taxation" (not saying what kind) undermines free markets. He also says that "land monopoly" is a barrier to free markets. He seems to be overlooking the extensive literature on using taxation of land values to offset and overcome the problem of land monopoly, and relieve commerce, labor, and capital from taxes that really do undermine free markets. The modern knee-jerk is "Oh, yes, Henry George", but before him there were John Locke, Baruch Spinoza, Jacob Vanderlint, A.R.J. Turgot, Francois Quesnay and the Physiocrats, Adam Smith, J.S. Mill, and others. Contemporary were Philip Wicksteed, Leon Walras, and others. After him came Harold Hotelling, Bill Vickrey, Lowell Harriss, Dick Netzer, Nicolaus Tideman, and a host of others - a large host, if we include those many who get the point but choose not to get heavily involved. Mason Gaffney