This is only obviously true if you evaluate average/total at a given time. Population ethicists tend to consider the population in a whole universe history. And in a big enough world, if you can only make changes at the margin then average utilitarianism is the same as critical-level total utilitarianism (where the critical level is set by the average of the population). Then it’s again possible that the animals have a positive contribution.
This is only obviously true if you evaluate average/total at a given time. Population ethicists tend to consider the population in a whole universe history. And in a big enough world, if you can only make changes at the margin then average utilitarianism is the same as critical-level total utilitarianism (where the critical level is set by the average of the population). Then it’s again possible that the animals have a positive contribution.
That’s interesting, I’ve never really thought about temporality, but I don’t see any reason why a future person would be valued less.
That said, I see critical level utilitarianism flawed for very similar reasons. I’ll probably write about it some time.