I think counterfactual analysis as a guide to making decisions is sometimes (!) a useful approach (especially if it is done with appropriate epistemic humility in light of the empirical difficulties).
But, tentatively, I don’t think that it is a valid method for calculating the impact an individual has had (or can be expected to have, if you calculate ex ante). I struggle a bit to put my thinking on this into words, but here’s an attempt: If I say “Alec [random individual] has saved 1,000 lives”, I think what I mean is “1,000 people now live because of Alec alone”. But if Alec was only able to save those lives with the help of twenty other people, and the 1,000 people would now be dead were it not for those twenty helpers, then it seems wrong to me to claim that the 1,000 survivors are alive only because of Alec—even if Alec played a vital role in the endeavour and if it would have been impossible to replace Alec by some other random individual. And just because any one of the twenty people were easily replaceable, I don’t think that they all suddenly count for nothing/very little in the impact evaluation; the fact seems to remain that Alec would not have been able to have any impact if he did not have twenty other people to help him… So it seems like an individual impact evaluation would need to include some sharing between Alec and the twenty other helpers; wouldn’t it??
Correct me if you (anyone reading this) think I’m misguided, but I believe the crux here is that I’m using a different definition of “impact” than the one that underlies counterfactual analysis. I agree that the impact definition underlying counterfactual analysis can sometimes be useful for making individual decisions, but I would argue that the definition I use can be helpful when talking about efforts to do good as a community and when trying to build a strategy for how to live one’s life over the long term (because it looks at what is needed for positive change in the aggregate).
This is a good question. I think, if we assume everything else equal (neither got the money by causing harm, both were influenced by roughly the same number of actors to be able and willing to donate their money), then I think I agree that the altruistic impact of the first is 100x that of the second.
I am not entirely sure what that implies for my own thinking on the topic. On the face of it, it clearly contradicts the conclusion in my Empirical problem section. But it does so without, as far as I can tell, addressing the subpoints I mention in that section. Does that mean the subpoints are not relevant to the empirical claim I make? They seem relevant to me, and that seems clear in examples other than the one you presented. I’m confused, and I imagine I’ll need at least a few more days to figure out how the example you gave changes my thinking.
Update: I am currently working on a Dialogue post with JWS to discuss their responses to the essay above and my reflections since publishing it. I imagine/hope that this will help streamline my thinking on some of the issues raised in comments (as well as some of the uncertainties I had while writing the essay). For that reason, I’ll hold off on comment responses here and on updates to the original essay until work on the Dialogue post has progressed a bit further, hoping to come back to this in a few days (max 1-1.5 weeks?) with a clearer take on whether & how comments such as this one by Jeff shift my thinking. Thanks again to all critical (and supportive) commenters for kicking off these further reflections!