Consequences, opportunities, and Arrovian theorems with consequentialist domains

We examine whether Arrow’s theorem holds when social alternatives are the pairs of final outcomes and opportunity sets from which outcomes are chosen, and there exist consequentialists in society. Consequentialism is a choice attitude towards outcomes and opportunities, and gives priority to outcomes over opportunities. We first prove Arrow’s theorem in an abstract setting, and show that domains in which all individuals are the same type of consequentialist are a model for this setting. If there coexist the different types of consequentialist in society, it is possible to construct an extended social welfare function which satisfies weak Pareto principle, independence of irrelevant alternatives and nondictatorship. Further, when we strengthen weak Pareto principle, we show that a theorem in Suzumura and Xu (2004) is incorrect and Arrow’s theorem holds even if there exists the diversity of the society within the territory of consequentialism. Journal of Economic Literature classification number: D63, D71