The Social Welfare Function

Abstract

Abstract This chapter provides a synopsis of the social welfare function (SWF) framework. It presents the key components of the framework, which are then developed in greater detail in subsequent chapters: an interpersonally comparable measure of well-being, which converts each outcome into a list (“vector”) of well-being numbers, one for each person in the population; a rule (the SWF) for ranking well-being vectors, such as the utilitarian SWF or a continuous-prioritarian SWF; and a procedure for ranking policies, understood as probability distributions across outcomes. The chapter then discusses the relation between the SWF methodology and ethics. This framework provides an ethical evaluation of governmental policies—an evaluation that is consequentialist and, specifically, welfarist. Finally, the chapter contrasts the SWF framework with cost-benefit analysis (CBA); and explains how the framework succeeds in producing a well-behaved ranking of outcomes and policies, notwithstanding Arrow’s theorem.