For well over a century, socialists, progressives, and even many Christians have railed against the capitalist exploitation of workers. They denounce capitalists—whether the Carnegies and Fricks of yesteryear or the Nikes of today—for paying low wages for hard work. Their antagonism toward individual and corporate targets is misplaced. The inexorable law of supply and demand, not greedy exploiters, determines wages. When the supply of labor exceeds capital’s demand for labor, wages are low. Carnegie could pay low wages because if Smith wasn’t willing to work for a pittance, Jones was. Why? Because those low wages were superior to Jones’ other...