 Cost-benefit analysis has more recently developed criteria which are very similar and rely on the summation of willingness to pay across the population. In spite of repeated criticism by specialists (Arrow 1951, Boadway and Bruce 1984, Sen 1979, Blackorby and Donaldson 1990), practitioners of cost-benefit analysis and some branches of economic theory (industrial organization, international economics) still commonly rely on such criteria. More sophisticated variants of cost-benefit analysis (Layard and Glaister 1994, Drèze and Stern 1987) avoid these problems by relying on weighted sums of willingness to pay or even on consistent social welfare functions. Adler (2012) offers a comprehensive study of the foundations of the social welfare function approach to cost-benefit analysis. Many specialists of public economics (e.g. Stiglitz 1987) have considered that the Pareto criterion was the core ethical principle on which economists should buttress their social evaluations, and that they should focus on denouncing all sources of inefficiency in social organizations and public policies.