1 Introduction
In “Utility Cascades”, Max Khan Hayward raises a purported problem for act-utilitarians (and their effective altruist brethren): namely, that they are vulnerable to utility cascades, which “occur when ongoing rational updating of judgements concerning the effectiveness of an intervention causes a utilitarian to push a situation further and further away from the antecedently optimific outcome” (Hayward, Reference Hayward2020: 433). Hayward argues that, when facing a utility cascade, utilitarians should either ignore evidence about the effectiveness of their interventions (“to ostrich”) or not apportion support for these interventions to their effectiveness.Footnote 1
If true, this would be a remarkable finding – and one with far-reaching import for those who wish to live by the light of act-utilitarianism, including, as Hayward notes, some members of the effective altruism movement. But, in what follows, I will argue that Hayward's article does not establish either of these claims, because, in principle, the sorts of act-utilitarians with which he is concerned will either (i) avoid the utility cascade or (ii) fail to avoid it but in an unobjectionable fashion. The night may be dark and full of terrors for diligent act-utilitarian effective altruists, but threats of utility cascades need not crowd out nightmares of the coming robot apocalypse.
2 Hayward's target
Hayward's targets are act-utilitarians of a particular stripe: let's call them expected utility maximizing act-utilitarians. Traditionally, act-utilitarianism is the view that one ought to take the available action that maximizes utility. Because we are rarely ever positioned to know which action actually maximizes utility, act-utilitarianism is rarely action-guiding – which is fine; the view is meant to provide an objective criterion of rightness, not a decision-procedure (Railton, Reference Railton1984). That said, act-utilitarianism is typically supplemented with a subjective criterion of rightness as well: one that says what one should do in light of one's beliefs about the consequences of one's actions.Footnote 2 One such proposal involves evaluating actions in terms of expected utility. An action's expected utility is the weighted sum of the utilities of its potential outcomes, where weights correspond to one's rational credence that that outcome will result.Footnote 3 On these views, what you objectively ought to do is perform the action that maximizes utility; and, what you subjectively ought to do is perform the action that maximizes expected utility.Footnote 4 Hayward's true target, I take it, is this latter view: namely, that one ought to maximize expected value.Footnote 5
The targeted view is embodied by Hayward's well-intentioned character, Bill, who undertakes a variety of doomed philanthropic spending initiatives. Bill participates in the effective altruism movement, which (according to Hayward (Reference Hayward2020: 440–41)),
combines the act-utilitarian doctrine that we should apportion our efforts according to efficiency with a doctrine concerning the acquisition of evidence about efficiency: that “We should employ the best empirical research methods available in order to determine, as best we can, which efforts promote those values most efficiently.” (Berkey, Reference Berkey2018: 147)Footnote 6
Following Hayward, I'll refer to this view as “act-utilitarianism”, although distinct positions share the name.
As previously mentioned, Hayward's conclusion is that utilitarian agents should sometimes either ignore evidence about, or fail to apportion support to, effectiveness. How are we to understand this “should”? If it's the objective “should”, Hayward's conclusion is undoubtedly true – but uninteresting. When evidence is misleading, it would be better objectively to ignore it; the initiative that is actually best is what should objectively be supported, not the initiative (if it is different) that is expectedly best. One doesn't need a utility cascade to show this, though; all one needs is an unpurchased winning lottery ticket. So, instead, I presume that the “should” in the conclusion is meant to be subjective: in some cases, act-utilitarians subjectively ought to ignore evidence, or subjectively ought to fail to apportion support in accordance with expected utility. This is, I take it, what Hayward's utility cascades are meant to show. I agree that, if they succeed in showing this, that's an interesting and troubling problem for those, like members of the effective altruism movement, who are broadly sympathetic to act-utilitarianism. But we have good reason, or so I'll argue, to be skeptical that Hayward's argument succeeds.
3 Unpacking Hayward's argument
The argument is developed narratively – Hayward engagingly sets forth two examples of a utility cascade: the first, an intrapersonal case; the second, an interpersonal case. In what follows, I focus on the former, developing lines of critique that have application in the interpersonal case as well.
3.1 The intrapersonal case: Bill and the vaccine initiative
Bill, Hayward's protagonist, is a wealthy philanthropist who is considering backing the rollout of a vaccine, effectanol. In June, the evidence available to Bill suggests that effectanol is 80% effective, which, given the good it could yield, means that the option donate $10,000 per month to effectanol maximizes expected utility. In July, Bill learns that the vaccine is only 70% effective, which changes his assignment of expected utilities so that, now, the option donate $8,000 per month to effectanol and $2,000 to mosquito nets maximizes expected utility.Footnote 7 But, because of Bill's reduced support, in August, Bill learns that the effectanol project is even less likely to succeed, making it the case that, now, the option donate $4,000 per month to effectanol and $6,000 to mosquito nets maximizes expected utility. Bill's reduced support makes it such that, in September, he is forced to conclude that the project is no longer worth investing in at all. Once all is said and done, Bill has wasted thousands on a vaccine program that is ultimately unsuccessful. He has, Hayward tells us, fallen victim to the eponymous “utility cascade”.
But what's the real problem here? Here's one way to read the case. Bill, we might say, has behaved in a way that brought about a sub-optimal outcome; as it turns out, it would've been better for him to have spent the entirety of his $10,000 per month on the mosquito nets all along. But, under conditions of uncertainty, bringing about an outcome that turns out to be sub-optimal isn't particularly objectionable. We do it every time we buy fire insurance and our house doesn't burn.
What about Hayward's claim that Bill would have done better to have ignored evidence? Hayward suggests that it would've been better for Bill to never learn that effectanol was only 70%, rather than 80%, effective. This suggests that the option donate $10,000 per month to effectanol is the one that maximizes actual utility – the optimal choice. But if that's right, then the information Bill received in July – the information that led him to conclude that effectanol was no longer worth donating $10,000 per month to – was misleading.Footnote 8 Of course, there is a sense in which it is better to disregard misleading information (it always is), but, given that Bill had no reason to suspect his evidence was misleading, there's nothing particularly objectionable about his having failed to do so.
On the other hand, it would be objectionable for Bill to predictably bring about a sub-optimal outcome or to knowingly fail to disregard misleading information. But, given that Bill is a rational act-utilitarian who maximizes expected utility, he won't do these things. If he knows an action will result in a sub-optimal outcome, its expected utility will be lower than that of some other; and, because Bill maximizes expected utility, he will avoid performing it.
Let's apply this last thought to Hayward's utility cascade. Suppose that, in July (after receiving the disappointing news about effectanol), Bill can predict that, if he lowers his monthly contribution from $10,000 to $8,000, there'll be a spike in infections which will make the initiative not worth donating $8,000 to (and likewise for lowering his monthly contribution from $8,000 to $4,000, and from $4,000 to $2,000, etc.). If Bill can predict this reliably, then the expected utility of lowering his contribution to $8,000 should be roughly the same as the expected utility of pulling his support altogether. After all, if Bill is attentive to all the consequences of his actions, he can predict that that's where he's headed. If that's right, Bill has two options still in the running:
A Continue donating $10,000 per month to effectanol.
B Pull all funding from effectanol and transfer it to mosquito nets.
The example doesn't provide us with enough detail to determine which option maximizes expected utility. If it's A, then, given that A maximizes actual utility, Bill ends up doing exactly what he objectively ought to do – and there's no sense in which it would've been better for him to have avoided July's evidence. On the other hand, if it's B, then Bill fails to do what is actually best, but only as a result of doing what made the most sense given the misleading information he'd been handed. Options that look best ex ante aren't always best ex post. This poses no new threat to act-utilitarianism.
Let me counter a potential response here – one Hayward gestures toward when he says, of suggestions like the one that Bill should assign low expected utility to lowering his contribution from $10,000 to $8,000, that:
[T]his does not vitiate the problem of utility cascades – it capitulates to them. It illustrates the limitations they place upon the deliberations of utilitarian agents. After all, this lowering of efficiency scores is based not on any innate feature of the situation, but on Bill's own vulnerability to cascades. […] [i]n this case, one of the limitations of the world is that it contains epistemically rational act-utilitarian agents. (Hayward, Reference Hayward2020: 438)
Hayward's idea is that, if Bill's reason for assigning low expected utility to lowering his contribution to $8,000 is that he anticipates that Bill-in-a-month-from-now will lower it even further (and so on and so on), this is still objectionable because it's an example of Bill obstructing himself.
I think this is mistaken. It's true that Bill (correctly) anticipates that, were he, in July, to lower his contribution to $8,000, he'd think, in August, that he was allocating too much to the initiative. But the reason he, in July, should assign low expected utility to lowering his contribution to $8,000 isn't because future-Bill will lower the contribution even further; instead, it's because, if he lowers the donation, the vaccine initiative won't be worth funding at that level – a fact that he can appreciate now as well as anticipate appreciating in a month from now. By assigning low expected utility to reducing his donation, Bill isn't capitulating to his future-self; he's not making a concession to a future decision that he, now, doesn't endorse; instead, he's responding to the fact that funding the initiative at $8,000 will result in it no longer being worth funding at that level.
It's not the cascade itself that explains why Bill assigns low expected value to the option; rather, it's the facts underlying the cascade – the facts about the effects his choices have on the initiative's success, to which his future-selves would be responding – which justify his evaluations of the options. So, contra Hayward, “this lowering of efficiency scores” is based on features of the situation, and not on Bill's vulnerability to cascades.
3.2 The interpersonal case: Bill (& co.) vs. climate change
The central lesson of the previous section – that act-utilitarians will either avoid the cascade or fail to do so but in a way that isn't objectionable – carries over to Hayward's interpersonal example regarding climate change. In this case, Bill is recognized by other philanthropists as an important contributor to charitable projects: his every move is scrutinized by others, who condition their own contributions on his. Now, either Bill knows that, for example, shifting his support from preventative measures to mitigative ones will herald a similar shift on the part of other members of his community (thus rendering the preventative measures less likely to succeed) or he doesn't.
Suppose he does know this. Then, given that he's a rational act-utilitarian, he will take that information into account when deciding what to do. So after receiving the first round of bad news about the efficacy of the preventative measures, it's not obvious that Bill is committed to shifting his contributions from prevention to mitigation. That bad news might lower the expected utility he assigns to the preventative strategy, but – given that, as we're supposing, he can predict that other members of his community will follow his lead – it's implausible that it will have lower expected utility than shifting his contributions from prevention to mitigation will. Why? Bill isn't shortsighted, so he knows that shifting his contributions away from prevention will eventually result in his (and the rest of the community) going all in for mitigation. So, unless Bill thinks that it's not worth putting any resources toward prevention, he'll regard keeping his contributions where they are as the better of the two options. As before, the cascade is avoided.
On the other hand, if Bill doesn't know that his decision will influence the behavior of the others, down the cascade he might go. But why is that a mark against act-utilitarianism? If it turns out that, unbeknownst to me, a murderous villain will destroy the planet if I snap my fingers, there's a sense (the objective one) in which I shouldn't snap my fingers; but, given that I don't know the influence my decision will have, how am I criticizable? Furthermore, as before, this is a case in which Bill receives misleading evidence about the effectiveness of the interventions – the evidence suggests that prevention isn't worth supporting at its current level when, in fact, it is.
Let me address a potential objection – analogous to the one from section 3.1 – which holds that, while Bill might be doing the best he can given the situation he's in, that situation would be even better if it didn't contain so may act-utilitarians.Footnote 9 The worry is that, if Bill's reason for assigning low expected utility to shifting his support from prevention to mitigation is that he anticipates that this will herald a similar shift on the part of the other members of his community, this is an example of act-utilitarians collectively getting in their own way. As before and for analogous reasons, I think this is mistaken. The reason Bill should assign low expected utility to shifting his resources away from prevention isn't because other members of the community will lower their contributions per se; instead, it's because, if he shifts his support away from prevention, prevention won't be worth funding by his peers either. His contributions – or lack thereof – alter the effectiveness of the interventions, which in turn affect (in ways he wholly endorses) what other act-utilitarians ought to do.
That said, one potentially important difference between Hayward's interpersonal case and his intrapersonal one is that Bill's peers might act contemporaneously – and, thus, without knowledge of what he and the others have likewise decided. This added degree of uncertainty might make it difficult – especially if the decisions are made independently and in ignorance of each other – for the community to coordinate on the optimal level of funding. But, as previously argued, it's far from clear that bringing about a sub-optimal outcome in the face of uncertainty is particularly objectionable.Footnote 10 And even if this were objectionable in some sense, it's not clear that it constitutes an objection to act-utilitarianism. Instead, all it shows is that act-utilitarianism is “indirectly collectively self-defeating” (Parfit, Reference Parfit1984: 27): things would be worse, by act-utilitarian lights, if everyone tried to behave like one. But (as argued in Parfit, Reference Parfit1984: 27–28) this doesn't show that act-utilitarianism is false – only that, if it's true, it would be worse if we all attempted to behave like it.
4 Conclusion
The versions of the examples in which Bill is vulnerable to sliding his way down a utility cascade involve two things: (i) misleading evidence, which pushes Bill away from the initiative that is, in fact, the one that it would be optimal to support; and, (ii) uncertainty surrounding the effects that Bill's decisions will have on the overall effectiveness of the available interventions. (In the versions without these features, Bill avoids the cascade.) Bringing about a sub-optimal outcome in these circumstances – that is, in the face of misleading evidence and under a thick fog of uncertainty – isn't particularly objectionable. Furthermore, the remedy for such situations, contra Hayward, is not to ignore evidence – it's to gather more of it. Subjectively, the best cure for misleading information is more information; and, a promising way for an act-utilitarian to avoid a utility cascade is to become better informed about the effects of their actions on both the effectiveness of the available interventions and the group dynamics of other altruistically minded agents.
I have argued that Hayward's utility cascades don't pose a significant worry for act-utilitarians in principle. But what about the members of the effective altruism movement? Are they vulnerable to utility cascades? Perhaps members of the effective altruist community are prone to naively evaluate interventions only in terms of their local effectiveness, ignoring the effects that their very support might have on the intervention's success. If so, I agree that this would be a mistake. But, I imagine, so would they; if this is a mistake effective altruists make, I doubt it's one that they'd endorse making. But, in any case, what's called for is more information, not less. The lesson I take from Hayward's examples is not that act-utilitarians should avoid evidence, or selectively ignore it, but that, rather, they should seek out as much information as possible. Their view does not license ostriching.
All that said, I think Hayward's utility cascades potentially do raise some very interesting issues – if not for impeccably rational expected utility maximizing act-utilitarians, then at least for the rest of us – about how best to navigate a complex, interconnected world. It might be that, in an environment replete with potential cascades, groups of expected utility maximizers will do worse – in some sense – than groups employing some other decision-rule. When maximizing is difficult, it might be better to not even try – to adopt some simple heuristic instead (e.g., Todd and Gigerenzer, Reference Todd, Gigerenzer, Todd and Gigerenzer2012).Footnote 11 That might be right, but more would be required to show it.Footnote 12
