In his latest column for the New York Times, leading liberal pundit and celebrated economist Paul Krugman takes on the new trend in the world of corporate tax avoidance, the practice of "inversion," which is what U.S. corporations call it when they pretend a foreign subsidiary is the real owner of their company as an excuse to shift profits away from America's higher corporate tax rate."The most important thing to understand about inversion," Krugman writes, "is that it does not in any meaningful sense involve American business 'moving overseas.'" Inversion, Krugman says, is "a purely paper transaction" but one that "deprive[s] the U.S.