Q. In step 2, Alice was definitely going to exist, which is why we paid $1. But then in step 3 Alice was no longer definitely going to exist. If we knew step 3 was going to happen, then we wouldn’t think Alice was definitely going to exist, and so we wouldn’t pay $1.
If your person-affecting view requires people to definitely exist, taking into account all decision-making, then it is almost certainly going to include only currently existing people. This does avoid the Dutch book but has problems of its own, most notably time inconsistency. For example, perhaps right before a baby is born, it take actions that as a side effect will harm the baby; right after the baby is born, it immediately undoes those actions to prevent the side effects.
Do you mean in the case where we don’t know yet for sure if we’ll have the option to undo the actions after the baby is born?
If we do know for sure the option will be available, we’ll be required to undo them, and the net welfare of those who will definitely exist anyway will be worse if we do the actions and then undo them than not taking them at all, then we wouldn’t take the actions that would harm the baby in the first place, because it’s worse for those who will definitely exist anyway.
A solution to time inconsistency could be to make commitments ahead of time, which is also a solution for some other decision-theoretic problems, like St. Petersburg lotteries for EU maximization with unbounded utility functions. Or, if we’re accepting time inconsistency in some cases, then we should acknowledge that our reasons for it aren’t generally decisive, and so not necessarily decisive against time inconsistent person-affecting views in particular.
I was imagining a local decision rule that was global in only one respect, i.e. choosing which people to consider based on who would definitely exist regardless of what decision-making happens. But in hindsight I think this is an overly complicated rule that no one is actually thinking about; I’ll delete it from the post.
Do you mean in the case where we don’t know yet for sure if we’ll have the option to undo the actions after the baby is born?
If we do know for sure the option will be available, we’ll be required to undo them, and the net welfare of those who will definitely exist anyway will be worse if we do the actions and then undo them than not taking them at all, then we wouldn’t take the actions that would harm the baby in the first place, because it’s worse for those who will definitely exist anyway.
A solution to time inconsistency could be to make commitments ahead of time, which is also a solution for some other decision-theoretic problems, like St. Petersburg lotteries for EU maximization with unbounded utility functions. Or, if we’re accepting time inconsistency in some cases, then we should acknowledge that our reasons for it aren’t generally decisive, and so not necessarily decisive against time inconsistent person-affecting views in particular.
I was imagining a local decision rule that was global in only one respect, i.e. choosing which people to consider based on who would definitely exist regardless of what decision-making happens. But in hindsight I think this is an overly complicated rule that no one is actually thinking about; I’ll delete it from the post.