I argue for the principle of Anonymity, according to which two populations are equally good whenever they have the same anonymous distribution of wellbeing. I first show that, given transitivity of the at-least-as-good-as relation, Anonymity is entailed by the ``Non-Identity Principle'', according to which the consequence of bringing better rather than worse lives into existence is, all else equal, better. I then argue for the Non-Identity Principle on the basis that if it were false, it would follow that we fail (...) to improve the world when we make existing people better off, while at the same time replacing worse-off future people with different better-off future people. Since this is implausible, we should accept the Non-Identity Principle, and therefore Anonymity as well. (shrink)

This essay introduces a new type of measure of social welfare, where populations are evaluated by their resemblance to an optimum population, which is an (in principle) possible population with the highest degree of social welfare, relative to some circumstances. Here it is argued to be the largest possible population where everyone fares maximally well. The new measure is responsive to quality of welfare, equality of welfare, and the number of people. It satisfies dominance and negative monotonicity, and it avoids (...) both the repugnant conclusion and a reverse repugnant conclusion for comparisons relative to our future on earth. (shrink)

In this essay I argue that even though egalitarianism and prioritarianism are different theories of social welfare, they can use the same social welfare measures. I present six different arguments for this thesis. The first argument is that conceptual connections between egalitarianism and prioritarianism ensure that any measure that works for either theory works for both. The second argument is that conditions necessary and sufficient to identify egalitarian and prioritarian measures, respectively, are equivalent. The third argument is that both egalitarianism (...) and prioritarianism can use two standard measures, typically proposed for only one theory. The fourth to sixth arguments contend that four properties that have been proposed as distinctive of either egalitarian or prioritarian measures cannot distinguish between them. I conclude that any egalitarian measure is also a prioritarian measure, and vice versa. (shrink)