Social choice with approximate interpersonal comparison of welfare gains

摘要

Suppose it is possible to make approximate interpersonal comparisons of welfare gains and losses. Thus, if w, x, y and z are personal states (each encoding all factors which influence the well-being of an individual), then it is sometimes possible to say "The welfare gain of the state change w (sic) x is greater than the welfare gain of the state change y (sic) z". We can represent this by the formula "(w (sic) x) >= (y (sic) z)", where (>=) is a difference preorder: an incomplete preorder on the space of all possible personal state changes. A social state change is a bundle of personal state changes. A social difference preorder (SDP) is an incomplete preorder on the space of social state changes, which satisfies Pareto and Anonymity axioms. We characterize a family of SDPs which are roughly utilitarian in nature. We also apply the model to redistributive taxation.