Another possible response is that ahead of time, each possible contingent individual may have an extraordinarily weak claim against you for possible harms to them, because they almost certainly won’t exist. But I’d guess this isn’t enough to capture the ex ante badness of bringing into existence an unknown individual who will probably have a bad life (e.g. factory farmed animals), so one of your other options or something else seems necessary anyway. Also, it may lead to some pretty odd dynamic inconsistency or other seemingly irrational behaviour like trying to avoid finding out who will be harmed in cases of many individuals at small individual risk of harm but large collective risk of at least one individual being harmed.
Thanks for writing this!
Another possible response is that ahead of time, each possible contingent individual may have an extraordinarily weak claim against you for possible harms to them, because they almost certainly won’t exist. But I’d guess this isn’t enough to capture the ex ante badness of bringing into existence an unknown individual who will probably have a bad life (e.g. factory farmed animals), so one of your other options or something else seems necessary anyway. Also, it may lead to some pretty odd dynamic inconsistency or other seemingly irrational behaviour like trying to avoid finding out who will be harmed in cases of many individuals at small individual risk of harm but large collective risk of at least one individual being harmed.