World A has a million people with an average utility of 10; world B has 100 people with an average utility of 11. Average utilitarianism says world B is preferable to world A. This seems counterintuitive as it has less total utility, but what if we reframe the question?
Imagine you are behind a veil of ignorance and you have to choose which world you will be instantiated into, becoming one citizen randomly selected from the population. From this perspective, world B is the obvious choice: even though it has far less total utility than word A, you personally get more utility by being instantiated into world B. This remains true even if world B only has 1 citizen, though most people, presumably, have "access to good company" in their utility function.
This reframing seems to invert my intuitions. Though this may just mean I am more selfish than most.
This has always been how I thought about it. (I consider myself approximately an Average Utilitarian, with some caveats that this is more descriptive than normative)
One person who disagreed with me said: "you are not randomly born into 'a person', you are randomly born into 'a collection of atoms.' A world with fewer atoms arranged into thinking beings increases the chance that you get zero utility, not whatever the average utility from among whichever patterns have developed consciousness"
I disagree with that person, but just wanted to float it as an alternate way of thinking.
It's the difference between SIA and SSA. If you work with SIA, then you're randomly chosen from all possible beings, and so in world B you're less likely to exist.