In recent years, the Harvard economist Roland Fryer has essentially tried to extend the M&M experiment to the scale of a metropolitan school system. He tested several different incentive programs in public schools—offering bonuses to teachers if they improved their classes’ test results; offering incentives like cell-phone minutes to students if they improved their own test results; offering families financial incentives if their children did better. The experiments were painstaking and carefully run—and the results have been almost uniformly disappointing.
