 The proponents of a “new” welfare economics (Hicks, Kaldor, Scitovsky) have distanced themselves from their predecessors (Marshall, Pigou, Lerner) by abandoning the idea of making social welfare judgments on the basis of interpersonal comparisons of utility. Their problem was then that in absence of any kind of interpersonal comparisons, the only principle on which to ground their judgments was the Pareto principle, according to which a situation is a global improvement if it is an improvement for every member of the concerned population (there are variants of this principle depending on how individual improvement is defined, in terms of preferences or some notion of well-being, and depending on whether it is a strict improvement for all members or some of them stay put). Since most changes due to public policy hurt some subgroups for the benefit of others, the Pareto principle remains generally silent. The need for a less restrictive criterion of evaluation has led Kaldor (1939) and Hicks (1939) to propose an extension of the Pareto principle through compensation tests. According to Kaldor’s criterion, a situation is a global improvement if ex post the gainers could compensate the losers. For Hicks’ criterion, the condition is that ex ante the losers could not compensate the gainers (a change from situation A to situation B is approved by Hicks’ criterion if the change from B to A is not approved by Kaldor’s criterion). These criteria are much less partial than the Pareto principle, but they remain partial (that is, they fail to rank many pairs of alternatives). This is not, however, their main drawback. They have been criticized for two basic flaws. First, for plausible definitions of how the compensation transfers could be computed, these criteria may lead to inconsistent social judgments: the same criterion may simultaneously declare that a situation A is better than another situation B, and conversely. Scitovsky (1941) has proposed to combine the two criteria, but this does not prevent the occurrence of intransitive social judgments. Second, the compensation tests have a dubious ethical value. If the compensatory transfers are performed in Kaldor’s criterion, then the Pareto criterion alone suffices since after compensation everybody gains. If the compensatory transfers are not performed, the losers remain losers and the mere possibility of compensation is a meager consolation to them. Such criteria are then typically biased in favor of the rich whose willingness to pay is generally high (i.e., they are willing to give a lot in order to obtain whatever they want, and therefore they can easily compensate the losers; when they do not actually pay the compensation, they can have the cake and eat it too).