While I think the Shapley value can be useful, there are clearly cases where the counterfactual value is superior for an agent deciding what to do. Derek Parfit clearly explains this in Five Mistakes in Moral Mathematics. He is arguing against the ‘share of the total view’ and but at least some of the arguments also apply to the Shapley value too (which is basically an improved version of ‘share of the total’). In particular, the best things you have listed in favour of the Shapley value applied to making a moral decision correctly apply when you and others are all making the decision ‘together’. If the others have already committed to their part in a decision, the counterfactual value approach looks better.
e.g. on your first example, if the other party has already paid their $1000 to P, you face a choice between creating 15 units of value by funding P or 10 units by funding the alternative. Simple application of Shapley value says you should do the action that creates 10 units, predictably making the world worse.
One might be able to get the best of both methods here if you treat cases like this where another agent has already committed to a known choice as part of the environment when calculating Shapley values. But you need to be clear about this. I consider this kind of approach to be a hybrid of the Shapley and counterfactual value approaches, with Shapley only being applied when the other agents’ decisions are still ‘live’. As another example, consider your first example and add the assumption that the other party hasn’t yet decided, but that you know they love charity P and will donate to it for family reasons. In that case, the other party’s decision, while not yet made, is not ‘live’ in the relevant sense and you should support P as well.
If you are going to pursue what the community could gain from considering Shapley values, then look into cases like this and subtleties of applying the Shapley value further — and do read that Parfit piece.
Sorry to revive a dead comment just to argue, but I’m going to disagree about the claims made here for most of what EA as a movement does, even if it’s completely right in many narrowly defined cases.
In most cases where we see that other funders have committed their funds before we arrive, you say that we should view it counterfactually. I think this is probably myopic. EA is a large funder, and this is an iterated dilemma—other actors are ‘live’ in the relevant sense, and will change their strategies based on knowing our decisions. The cooperative and overall better solution, if we can get other actors to participate in this pareto-improving change in strategy, is to explicitly cooperate, or at least embrace a decision theory that lets us do so.
(See the discussion here that pointed me back to this comment, where I make a similar argument. And in the post, I point to where Givewell is actively using counterfactual reasoning when the other decisions are most certainly ‘live’, because again, it’s an iterated game, and the other funders have already said they are adjusting their funding levels to account for the funding that EA provides.)
While I think the Shapley value can be useful, there are clearly cases where the counterfactual value is superior for an agent deciding what to do. Derek Parfit clearly explains this in Five Mistakes in Moral Mathematics. He is arguing against the ‘share of the total view’ and but at least some of the arguments also apply to the Shapley value too (which is basically an improved version of ‘share of the total’). In particular, the best things you have listed in favour of the Shapley value applied to making a moral decision correctly apply when you and others are all making the decision ‘together’. If the others have already committed to their part in a decision, the counterfactual value approach looks better.
e.g. on your first example, if the other party has already paid their $1000 to P, you face a choice between creating 15 units of value by funding P or 10 units by funding the alternative. Simple application of Shapley value says you should do the action that creates 10 units, predictably making the world worse.
One might be able to get the best of both methods here if you treat cases like this where another agent has already committed to a known choice as part of the environment when calculating Shapley values. But you need to be clear about this. I consider this kind of approach to be a hybrid of the Shapley and counterfactual value approaches, with Shapley only being applied when the other agents’ decisions are still ‘live’. As another example, consider your first example and add the assumption that the other party hasn’t yet decided, but that you know they love charity P and will donate to it for family reasons. In that case, the other party’s decision, while not yet made, is not ‘live’ in the relevant sense and you should support P as well.
If you are going to pursue what the community could gain from considering Shapley values, then look into cases like this and subtleties of applying the Shapley value further — and do read that Parfit piece.
Sorry to revive a dead comment just to argue, but I’m going to disagree about the claims made here for most of what EA as a movement does, even if it’s completely right in many narrowly defined cases.
In most cases where we see that other funders have committed their funds before we arrive, you say that we should view it counterfactually. I think this is probably myopic. EA is a large funder, and this is an iterated dilemma—other actors are ‘live’ in the relevant sense, and will change their strategies based on knowing our decisions. The cooperative and overall better solution, if we can get other actors to participate in this pareto-improving change in strategy, is to explicitly cooperate, or at least embrace a decision theory that lets us do so.
(See the discussion here that pointed me back to this comment, where I make a similar argument. And in the post, I point to where Givewell is actively using counterfactual reasoning when the other decisions are most certainly ‘live’, because again, it’s an iterated game, and the other funders have already said they are adjusting their funding levels to account for the funding that EA provides.)