Finger-wagging moralizers say the love of money is the root of all evil. They assume that making a lot of money requires exploiting others, and that the best way to wash off the resulting stain is to give a lot of it away. In Why It's OK to Want to Be Rich, Jason Brennan shows that the moralizers have it backwards. He argues that, in general, the more money you make, the more you already do for others, and that even an average wage...