William MacAskill

In the final pages of On What Matters, Volume II, Derek Parfit comments: ‘We live during the hinge of history... If we act wisely in the next few centuries, humanity will survive its most dangerous and decisive period... What now matters most is that we avoid ending human history.’ This passage echoes Parfit's comment, in Reasons and Persons, that ‘the next few centuries will be the most important in human history’. But is the claim that we live at the hinge of history true? The argument of this paper is that it is not. The paper first suggests a way of making the hinge of history claim precise and action-relevant in the context of the question of whether altruists should try to do good now, or invest their resources in order to have more of an impact later on. Given this understanding, there are two worldviews - the Time of Perils and Value Lock-in views - on which we are indeed living during, or about to enter, the hinge of history. This paper then presents two arguments against the hinge of history claim: first, that it is a priori extremely unlikely to be true, and that the evidence in its favour is not strong enough to overcome this a priori unlikelihood; second, an inductive argument that our ability to influence events has been increasing over time, and we should expect that trend to continue into the future. The paper concludes by considering two additional arguments in favour of the claim, and suggests that though they have some merit, they are not sufficient for us to think that the present time is the most important time in the history of civilisation. GPI Working Paper No. 12-2020

Given plausible assumptions about the long-run impact of our everyday actions, we show that standard non-consequentialist constraints on doing harm entail that we should try to do as little as possible in our lives. We call this the Paralysis Argument. After laying out the argument, we consider and respond to a number of objections. We then suggest what we believe is the most promising response: to accept, in practice, a highly demanding morality of beneficence with a long-term focus. GPI Working Paper No. 6-2019.

Effective altruism is the use of evidence and careful reasoning to work out how to maximize positive impact on others with a given unit of resources, and the taking of action on that basis. It’s a philosophy and a social movement that is gaining considerable steam in the philanthropic world. For example, GiveWell, an organization that recommends charities working in global health and development and generally follows effective altruist principles, moves over $90 million per year to its top recommendations. Giving What We Can, which encourages individuals to pledge at least 10% of their income to the most cost-effective charities, now has over 3500 members, together pledging over $1.5 billion of lifetime donations. Good Ventures is a foundation, founded by Dustin Moskovitz and Cari Tuna, that is committed to effective altruist principles; it has potential assets of $11 billion, and is distributing over $200 million each year in grants, advised by the Open Philanthropy Project. [...] GPI Working Paper No. 8-2019

True benevolence is, most fundamentally, a desire that the world be better. It is natural and common, however, to frame thinking about benevolence indirectly, in terms of a desire to make a difference to how good the world is. This would be an innocuous shift if desires to make a difference were extensionally equivalent to desires that the world be better. This paper shows that at least on some common ways of making a “desire to make a difference” precise, this extensional equivalence fails. Where it fails, “difference-making preferences” run counter to the ideals of benevolence. In particular, in the context of decision making under uncertainty, coupling a “difference-making” framing in a natural way with risk aversion leads to preferences that violate stochastic dominance, and that lead to a strong form of collective defeat, from the point of view of betterness. Difference-making framings and true benevolence are not strictly mutually inconsistent, but agents seeking to implement true benevolence must take care to avoid the various pitfalls that we outline. GPI Working Paper No. 16-2022

This chapter makes the case for strong longtermism: the claim that, in many situations, impact on the long-run future is the most important feature of our actions. Our case begins with the observation that an astronomical number of people could exist in the aeons to come. Even on conservative estimates, the expected future population is enormous. We then add a moral claim: all the consequences of our actions matter. In particular, the moral importance of what happens does not depend on when it happens. That pushes us toward strong longtermism. We then address a few potential concerns, the first of which is that it is impossible to have any sufficiently predictable influence on the course of the long-run future. We argue that this is not true. Some actions can reasonably be expected to improve humanity’s long-term prospects. These include reducing the risk of human extinction, preventing climate change, guiding the development of artificial intelligence, and investing funds for later use. We end by arguing that these actions are more than just extremely effective ways to do good. Since the benefits of longtermist efforts are large and the personal costs are comparatively small, we are morally required to take up these efforts.

Suppose that an altruistic agent who is uncertain between evidential and causal decision theory finds herself in a situation where these theories give conflicting verdicts. We argue that even if she has significantly higher credence in CDT, she should nevertheless act in accordance with EDT. First, we claim that the appropriate response to normative uncertainty is to hedge one's bets. That is, if the stakes are much higher on one theory than another, and the credences you assign to each of these theories are not very different, then it is appropriate to choose the option that performs best on the high-stakes theory. Second, we show that, given the assumption of altruism, the existence of correlated decision makers will increase the stakes for EDT but leave the stakes for CDT unaffected. Together these two claims imply that whenever there are sufficiently many correlated agents, the appropriate response is to act in accordance with EDT.

It has been argued that evolutionary considerations favour utilitarianism by selectively debunking its competitors. However, evolutionary considerations also seem to undermine the practical significance of utilitarianism, since commonsense beliefs about well-being seem like prime candidates for evolutionary debunking. We argue that the practical significance of utilitarianism is not undermined in this way if we understand the requirements of practical rationality as sensitive to normative uncertainty. We consider the view that rational decision-making under normative uncertainty requires maximizing expected choice-worthiness, as well as the possibility that different theories’ choice-worthiness rankings are not all interval-scale measurable or intertheoretically comparable. Finally, we suggest how evolutionary considerations may increase the practical significance of utilitarianism even if belief in utilitarianism is debunked by evolutionary considerations, so long as belief in competing theories is undermined to an even greater extent.

Many everyday actions have major but unforeseeable long-term consequences. Some argue that this fact poses a serious problem for consequentialist moral theories. We argue that the problem for non-consequentialists is greater still. Standard non-consequentialist constraints on doing harm combined with the long-run impacts of everyday actions entail, absurdly, that we should try to do as little as possible. We call this the Paralysis Argument. After laying out the argument, we consider and respond to a number of objections. We then suggest what we believe is the most promising response: to accept, in practice, a highly demanding morality of beneficence with a long-term focus.

In all probability, future generations will outnumber us by thousands or millions to one. In the aggregate, their interests therefore matter enormously, and anything we can do to steer the future of civilization onto a better trajectory is of tremendous moral importance. This is the guiding thought that defines the philosophy of longtermism. Political science tells us that the practices of most governments are at stark odds with longtermism. But the problems of political short-termism are neither necessary nor inevitable. In principle, the state could serve as a powerful tool for positively shaping the long-term future. In this chapter, we make some suggestions about how to align government incentives with the interests of future generations. First, in Section II, we explain the root causes of political short-termism. Then, in Section III, we propose and defend four institutional reforms that we think would be promising ways to increase the time horizons of governments: 1) government research institutions and archivists; 2) posterity impact assessments; 3) futures assemblies; and 4) legislative houses for future generations. Section IV concludes with five additional reforms that are promising but require further research: to fully resolve the problem of political short-termism we must develop a comprehensive research program on effective longtermist political institutions.

Effective altruism is the use of evidence and reason to figure out how to benefit others as much as possible and the taking of action on that basis. This chapter discusses the moral framework and methodological approach that effective altruism uses to prioritize causes, charities, and careers, and examines some of the world problems that, on this perspective, appear to be most urgent and important: global health and development, non-human animal suffering, and risks to long-term human survival. It then lays out some of the most important unsolved problems facing the effective altruist project.

A major problem for interpersonal aggregation is how to compare utility across individuals; a major problem for decision-making under normative uncertainty is the formally analogous problem of how to compare choice-worthiness across theories. We introduce and study a class of methods, which we call statistical normalization methods, for making interpersonal comparisons of utility and intertheoretic comparisons of choice-worthiness. We argue against the statistical normalization methods that have been proposed in the literature. We argue, instead, in favor of normalization of variance: we claim that this is the account that most plausibly gives all individuals or theories ‘equal say’. To this end, we provide two proofs that variance normalization has desirable properties that all other normalization methods lack, though we also show how different assumptions could lead one to axiomatize alternative statistical normalization methods.

This paper argues in favor of a particular account of decision‐making under normative uncertainty: that, when it is possible to do so, one should maximize expected choice‐worthiness. Though this position has been often suggested in the literature and is often taken to be the ‘default’ view, it has so far received little in the way of positive argument in its favor. After dealing with some preliminaries and giving the basic motivation for taking normative uncertainty into account in our decision‐making, we consider and provide new arguments against two rival accounts that have been offered—the accounts that we call ‘My Favorite Theory’ and ‘My Favorite Option’. We then give a novel argument for comparativism—the view that, under normative uncertainty, one should take into account both probabilities of different theories and magnitudes of choice‐worthiness. Finally, we further argue in favor of maximizing expected choice‐worthiness and consider and respond to five objections.

In the article, ‘Being Good in a World of Need: Some Empirical Worries and an Uncomfortable Philosophical Possibility,’ Larry Temkin presents some concerns about the possible impact of international aid on the poorest people in the world, suggesting that the nature of the duties of beneficence of the global rich to the global poor are much more murky than some people have made out. In this article, I’ll respond to Temkin from the perspective of effective altruism—one of the targets he attacks. I’ll argue that Temkin’s critique has little empirical justification, given the conclusions he wants to reach, and is therefore impotent.

A number of philosophers have claimed that we should take not just empirical uncertainty but also fundamental moral uncertainty into account in our decision-making, and that, despite widespread moral disagreement, doing so would allow us to draw robust lessons for some issues in practical ethics. In this article, I argue that, so far, the implications for practical ethics have been drawn too simplistically. First, the implications of moral uncertainty for normative ethics are far more wide-ranging than has been noted so far. Second, one can't straightforwardly argue from moral uncertainty to particular conclusions in practical ethics, both because of ‘interaction’ effects between moral issues, and because of the variety of different possible intertheoretic comparisons that one can reasonably endorse.

We are often unsure about what we ought to do. This can be because we lack empirical knowledge, such as the extent to which future generations will be harmed by climate change. It can also be because we lack normative knowledge, such as the relative moral importance of the interests of present people and the interests of future people. However, though the question of how one ought to act under empirical uncertainty has been addressed extensively by both economists and philosophers---with expected utility theory providing the standard formal framework---the question of how one ought to act under normative uncertainty is comparatively neglected. My thesis attempts to address this gap. In my thesis I develop a view that I call metanormativism: that there are second-order norms that govern action that are relative to a decision-maker's uncertainty about first-order norms. In the first part of the thesis, I defend one specific metanormative view: that under normative uncertainty decision-makers should maximise expected choice-worthiness, treating normative uncertainty analogously with empirical uncertainty. Drawing on the analogy between decision-making under normative uncertainty and social choice theory, I defend this view at length in response to the problem of merely ordinal theories and the problem of intertheoretic value comparisons. In the second part of the thesis, I explore the implications of metanormativism for other philosophical issues. I argue that it has important consequences regarding the theory of rational action in the face of incomparable values, the causal/evidential debate in decision-theory, and our assessment of the value of moral philosophy.

The cofounder of the Effective Altruism movement presents a counterintuitive approach anyone can use to make a difference in the world. While studying philosophy at Oxford University and trying to work out how he could have the greatest impact, William MacAskill discovered that most of the time and money aimed at making the world a better place achieves little. Why? Because individuals rarely have enough information to make the best choices. Confronting this problem head-on, MacAskill developed the concept of effective altruism, a scientific, data-driven approach to making a difference that operates by asking these five questions: How much will this action improve others' lives? Is this the most effective action I can take? How useful is my contribution, given what others are already doing? What will happen if I don't do it? What are the chances of success, and how good would success be? Applying these principles, he demonstrates that many of our assumptions about doing good are misguided: he argues that one can potentially save more lives by working on Wall Street than as a heart surgeon, that cancer charities are not the best use of money, and that buying sweatshop-produced goods is a form of ethical consumption. MacAskill challenges us to think differently but argues that if we set aside our biases and rely on evidence and careful reasoning, each of us can make a tremendous difference.

In this paper I propose an approach to decision theory that I call metanormativism, where the key idea is that decision theory should take into account decision-theoretic uncertainty. I don’t attempt to argue in favor of this view, though I briefly offer some motivation for it. Instead, I argue that if the view is correct, it has important implications for the causal versus evidential decision-theory debate. First, it allows us to make rational sense of our seemingly divergent intuitions across the Smoking Lesion and The Psychopath Button cases. Second, it generates strong new arguments for preferring the causal approach to decision-theory over the evidential approach.

Some philosophers have recently argued that decision-makers ought to take normative uncertainty into account in their decisionmaking. These philosophers argue that, just as it is plausible that we should maximize expected value under empirical uncertainty, it is plausible that we should maximize expected choice-worthiness under normative uncertainty. However, such an approach faces two serious problems: how to deal with merely ordinal theories, which do not give sense to the idea of magnitudes of choice-worthiness; and how, even when theories do give sense to magnitudes of choice-worthiness, to compare magnitudes of choice-worthiness across different theories. Some critics have suggested that these problems are fatal to the project of developing a normative account of decision-making under normative uncertainty. The primary purpose of this article is to show that this is not the case. To this end, I develop an analogy between decision-making under normative uncertainty and the problem of social choice, and then argue that the Borda Rule provides the best way of making decisions in the face of merely ordinal theories and intertheoretic incomparability.

In “Rejecting Ethical Deflationism,” Jacob Ross argues that a rational decision maker is permitted, for the purposes of practical reasoning, to assume that nihilism is false. I argue that Ross’s argument fails because the principle he relies on conflicts with more plausible principles of rationality and leads to preference cycles. I then show how the infectiousness of nihilism, and of incomparability more generally, poses a serious problem for the larger project of attempting to incorporate moral uncertainty into expected value maximization style reasoning.