Also, this seems like a bad decision theory. I can’t estimate the longterm effects of eating an apple, but that doesn’t imply that I should starve due to indecision.
Longtermism is the claim (or thesis) that we can do the most good by focusing on effects going into the longterm future:
Let strong longtermism be the thesis that in a wide class of decision situations, the option that is ex ante best is contained in a fairly small subset of options whose ex ante effects on the very long-run future are best.
Also, this seems like a bad decision theory. I can’t estimate the longterm effects of eating an apple, but that doesn’t imply that I should starve due to indecision.
Longtermism wouldn’t say you should die, just that, unless you know more, it wouldn’t say that you shouldn’t die either.
You can’t work on longtermist interventions if you die, though, and doing so might be robustly better than dying.
Is this longtermism?
List all possible actions {A1,..,AK}.
For each action Aj, calculate expected value Vt(Aj) over t=1:∞, using the social welfare function.
If we can’t calculate Vt for some t, due to cluelessness, then skip over that action.
Out of the remaining actions, choose the action with the highest expected value.
Or, (3′): if we can’t calculate Vt for Ai and Aj, then assume that they’re equal, and rank them by using their expected value over periods before t.
So longtermism is not a general decision theory, and is only meant to be applied narrowly?
Longtermism is the claim (or thesis) that we can do the most good by focusing on effects going into the longterm future:
https://globalprioritiesinstitute.org/hilary-greaves-william-macaskill-the-case-for-strong-longtermism/