Background: Most economists share a moral commitment to the ideal of perfect competition. This commitment is based, primarily, on 2 claims: (1) perfect competition yields Pareto-improvements (and, at the limit, Pareto-optimality); (2) Pareto-improvements are moral improvements. (This second claim should be understood as meaning all Pareto-improvements are thereby moral improvements, not that all moral improvements are Pareto improvements.) Some of you are probably familiar with the first claim, but this paper is focused on the second, more unfamiliar, claim. Why do economists generally claim that Pareto-improvements are moral improvements? Is this claim true? If not, what exactly is the moral importance of striving for Pareto-optimality (if there is any)?