Wealthy investors often invest in hedge funds. Hedge fund managers use investors' money to buy stocks, bonds, and other investments with the intention of earning high returns. But an article in the New York Times notes, "Even professionals have a problem in evaluating hedge fund performance, because distinguishing skill from luck ... is extremely difficult." Is it ever easy to determine whether a firm making an economic profit is doing so because of the skills of the firm's managers or because of luck? Briefly explain.