"Two Criteria for Social Decisions" Marc Fleurbaey Nuffield College, University of Oxford Abstract: This paper studies the ethical underpinnings of two social criteria which are prominent in the literature dealing with the problem of evaluating allocations of several consumption goods in a population with heteregenous preferences. The Pazner-Schmeidler criterion (Pazner-Schmeidler 1978) and the Walrasian criterion (Fleurbaey and Maniquet 1996) are prima facie quite different. But it is shown here that these criteria are related to close variants of the fairness condition that an allocation is better when every individual bundle in it dominates the average consumption in another allocation. In addition, the results suggest that the Pazner-Schmeidler criterion can be viewed as the best extension of the Walrasian criterion to non-convex economies. JEL Classification: D63, D71 Keywords: social welfare, social choice, fairness