In the mid-nineteenth century, the French economist Frederic Bastiat distinguished between good and bad economists by focusing on whether they thought through the long-run consequences of their arguments. According to Bastiat, a good economist was not blinded by the possible short-run gains to be attained by pursuing a certain course of action, but asked the question, “What will be the long-run consequences of doing that?” Bastiat was saying that the good economist worries about what we today call unintended consequences, whereas the bad economist considers only the immediate and visible consequences. While Bastiat’s point was couched in terms of economists,...