New submitter rvw sends word that Bill Gates has posted a review of Capital in the Twenty-First Century, an acclaimed book by economist Thomas Piketty about how income equality is a necessary result of unchecked capitalism. Gates, one of the most successful capitalists of our time, agrees with Piketty's most important conclusions. That said, he also finds parts of the book to be flawed and incomplete, but says Piketty has started vital debate on these issues. Gates writes, Yes, some level of inequality is built in to capitalism. As Piketty argues, it is inherent to the system. The question is, what level of inequality is acceptable? And when does inequality start doing more harm than good? That's something we should have a public discussion about, and it's great that Piketty helped advance that discussion in such a serious way. ... I agree that taxation should shift away from taxing labor. It doesn't make any sense that labor in the United States is taxed so heavily relative to capital. It will make even less sense in the coming years, as robots and other forms of automation come to perform more and more of the skills that human laborers do today. But rather than move to a progressive tax on capital, as Piketty would like, I think we'd be best off with a progressive tax on consumption.