FOR a century, regulation by government and modesty on the part of business leaders have guided efforts to preserve and improve the capitalist system. The phrase “There oughta be a law” captures the spirit of that impulse, and experience has largely vindicated its worth. In the latter part of the nineteenth century, when the country risked having its key industries fall to monopolists or cartels, Congress enacted antitrust laws that in no small way helped to preserve competitive markets in the United States. These laws also affirmed the idea that social mobility should not be unreasonably restricted in the American economy.