CRITICAL LEVELS AND THE (REVERSE) REPUGNANT CONCLUSION

It is well-known that there is a trade-off among the properties of pop ulation principles that are used to make social evaluations when the n umber of people in the society under consideration may vary. The commo nly used principles either lead to the repugnant conclusion (which is the case for classical utilitarianism), or they violate the Pareto-plu s principle and related properties (average utilitarianism is an examp le of such a principle). This paper examines the nature of this trade- off and shows that the incompatibility between avoiding the repugnant conclusion and the Pareto-plus principle is fundamental and not restri cted to the commonly used population principles.