Both The Economist and Bloomberg have focused on new monopolies in the past few months, and a key problem has been quantifying the "moat" that provides companie

Both The Economist and Bloomberg have focused on new monopolies in the past few months, and a key problem has been quantifying the "moat" that provides companies with a lasting advantage. Seems to me that a "moat" is most easily quantified by the share market total capitalization, and to disrupt monopolies, simply introduce a tax on total market value for a firm.