How to Avoid Both the Repugnant and Sadistic Conclusions without Dropping Standard Axioms in Population Economics

TL;DR

This paper shows that certain acceptable social welfare orderings can avoid both the repugnant and sadistic conclusions in population ethics without dropping standard axioms, but strengthening avoidance criteria leads to new impossibilities.

Contribution

It demonstrates that acceptable social welfare orderings can prevent both conclusions while adhering to standard axioms, and explores the conflicts arising from strengthening avoidance requirements.

Findings

Acceptable social welfare orderings can avoid both conclusions.

Strengthening avoidance leads to new impossibility results.

Conflicts exist between independence axiom and avoiding the weak repugnant conclusion.

Abstract

This study investigates possibility and impossibility results of the repugnant and sadistic conclusions in population ethics and economics. The repugnant conclusion says that an enormous population with very low well-being is socially better than any smaller population with sufficiently high well-being. The sadistic conclusion says that adding individuals with negative well-being to a society is socially better than adding individuals with positive well-being to it. Previous studies have often found it challenging to avoid both undesirable conclusions. However, I demonstrate that a class of acceptable social welfare orderings can easily prevent these conclusions while adhering to standard axioms, such as anonymity, strong Pareto, Pigou-Dalton transfer, and extended continuity. Nevertheless, if the avoidance requirements for the repugnant and sadistic conclusions are strengthened, it is possible to encounter new impossibility results. These results reveal essential conflicts between the independence axiom and the avoidance of the weak repugnant conclusion when evaluating well-being profiles with different populations.