At Christmas, we traditionally retell Dickens's story of Scrooge, who cared more for money than for his fellow human beings. What would we think of a Scrooge who could cure diseases that blighted thousands of people's lives but did not do so? Clearly, we would be horrified. But this has increasingly been happening in the name of economics, under the innocent sounding guise of "intellectual property rights." Intellectual property differs from other property—restricting its use is inefficient as it costs nothing for another person to use it. Thomas Jefferson, America's third president, put it more poetically than modern economists (who...