As a manufacturer of economic inequality, the underlying causes are something I know about. Yes, there are a lot of people who get rich through rent-seeking of various forms, and a lot who get rich by playing games that though not crooked are zero-sum. But there are also a significant number who get rich by creating wealth. And that group presents two problems for the hunter of economic inequality. One is that variation in productivity is accelerating. The rate at which individuals can create wealth depends on the technology available to them, and that grows exponentially. The other problem with creating wealth, as a source of inequality, is that it can expand to accommodate a lot of people. I'm all for shutting down the crooked ways to get rich. But that won't eliminate great variations in wealth, because as long as you leave open the option of getting rich by creating wealth, people who want to get rich will do that instead. - www.paulgraham.com