 In the first half of the twentieth century, most leading economists (Pigou, Hicks, Kaldor, Samuelson, Arrow etc.) devoted a significant part of their research effort to normative issues, notably the definition of criteria for the evaluation of public policies. The situation is very different nowadays. “Economists do not devote a great deal of time to investigating the values on which their analyses are based. Welfare economics is not a subject which every present-day student of economics is expected to study”, writes Atkinson (2001, p. 195), who regrets “the strange disappearance of welfare economics”. Normative economics itself may be partly guilty for this state of affairs, in view of its repeated failure to provide conclusive results and its long-lasting focus on impossibility theorems (see  § 4.1).  But there has also been a persistent ambiguity about the status of normative propositions in economics. The subject matter of economics and its close relation to policy advice make it virtually impossible to avoid mingling with value judgments. Nonetheless, the desire to separate positive statements from normative statements has often been transformed into the illusion that economics could be a science only by shunning the latter. Robbins (1932) has been influential in this positivist move, in spite of a late clarification (Robbins 1981) that his intention was not to disparage normative issues, but only to clarify the normative status of (useful and necessary) interpersonal comparisons of welfare. It is worth emphasizing that many results in normative economics are mathematical theorems with a primary analytical function. Endowing them with a normative content may be confusing, because they are most useful in clarifying ethical values and do not imply by themselves that these values must be endorsed. “It is a legitimate exercise of economic analysis to examine the consequences of various value judgments, whether or not they are shared by the theorist.” (Samuelson 1947, p. 220) The role of ethical judgments in economics has received recent and valuable scrutiny in Sen (1987), Hausman and McPherson (2006) and Mongin (2001b).