H. Orri Stefansson

Stockholm University
Institute for Futures Studies
  •  164
    Fairness, ambiguity and dynamic consistency
    Theory and Decision. forthcoming.
    Considerations of dynamic inconsistency have figured prominently in debates over the rationality of preferences that violate the separability conditions characteristic of expected utility theory. These debates have mostly focused on risk- and ambiguity averse preferences, but analogous considerations apply to preferences for fairness. We revisit these debates in the context of a specific hypothesis regarding the violations of separability by such preferences, namely that they are potentially bot…Read more
  •  20
    Incommensurability, the sequence argument, and the Pareto principle
    Philosophical Studies 181 (12): 3395-3411. 2024.
    Parfit (Theoria 82:110–127, 2016) responded to the Sequence Argument for the Repugnant Conclusion by introducing imprecise equality. However, Parfit’s notion of imprecise equality lacked structure. Hájek and Rabinowicz (2022) improved on Parfit’s proposal in this regard, by introducing a notion of degrees of incommensurability. Although Hájek and Rabinowicz’s proposal is a step forward, and may help solve many paradoxes, it can only avoid the Repugnant Conclusion at great cost. First, there is a…Read more
  •  56
    Recently, Martin Smith defended a view he called the “normic de minimis expected utility theory”. The basic idea is to integrate a ‘normic’ version of the de minimis principle into an expected utility-based decision theoretical framework. According to the de minimis principle some risks are so small (falling below a threshold) that they can be ignored. While this threshold standardly is defined in terms of some probability, the normic conception of de minimis defines this threshold in terms of a…Read more
  •  392
    Climate Change and Decision Theory
    In Pellegrino Gianfranco & Marcello Di Paola (eds.), Handbook of Philosophy of Climate Change, Springer Nature. pp. 267-286. 2023.
    Many people are worried about the harmful effects of climate change but nevertheless enjoy some activities that contribute to the emission of greenhouse gas (driving, flying, eating meat, etc.), the main cause of climate change. How should such people make choices between engaging in and refraining from enjoyable greenhouse-gas-emitting activities? In this chapter, we look at the answer provided by decision theory. Some scholars think that the right answer is given by interactive decision theory…Read more
  •  273
    A trilemma for the lexical utility model of the precautionary principle
    Philosophical Studies 181 (12): 3271-3287. 2024.
    Bartha and DesRoches (Synthese 199(3–4):8701–8740, 2021) and Steel and Bartha (Risk Analysis 43(2):260–268, 2023) argue that we should understand the precautionary principle as the injunction to maximise lexical utilities. They show that the lexical utility model has important pragmatic advantages. Moreover, the model has the theoretical advantage of satisfying all axioms of expected utility theory except continuity. In this paper I raise a trilemma for any attempt at modelling the precautionary…Read more
  •  508
    Fairness and risk attitudes
    Philosophical Studies 180 (10-11): 3179-3204. 2023.
    According to a common judgement, a social planner should often use a lottery to decide which of two people should receive a good. This judgement undermines one of the best-known arguments for utilitarianism, due to John C. Harsanyi, and more generally undermines axiomatic arguments for utilitarianism and similar views. In this paper we ask which combinations of views about (a) the social planner’s attitude to risk and inequality, and (b) the subjects’ attitudes to risk are consistent with the af…Read more
  •  404
    In defence of Pigou-Dalton for chances
    Utilitas 35 (4): 292-311. 2023.
    I defend a weak version of the Pigou-Dalton principle for chances. The principle says that it is better to increase the survival chance of a person who is more likely to die rather than a person who is less likely to die, assuming that the two people do not differ in any other morally relevant respect. The principle justifies plausible moral judgements that standard ex post views, such as prioritarianism and rank-dependent egalitarianism, cannot accommodate. However, the principle can be just…Read more
  •  532
    Rowe has recently argued that pure risk of harm cannot itself be a harm. I respond to Rowe and argue that given an appropriate understanding of objective probabilities, pure objective risk of harm can itself be a harm.
  •  457
    Many philosophers think that we should use a lottery to decide who gets a good to which two persons have an equal claim but which only one person can get. Some philosophers think that we should save identified persons from harm even at the expense of saving a somewhat greater number of statistical persons from the same harm. I defend a principled way of justifying both judgements, namely, by appealing to the decreasing marginal moral value of survival chances. I identify four desiderata that, I …Read more
  •  438
    Longtermism and social risk-taking
    In Jacob Barrett, Hilary Greaves & David Thorstad (eds.), Essays on Longtermism, Oxford University Press. forthcoming.
    A social planner who evaluates risky public policies in light of the other risks with which their society will be faced should judge favourably some such policies even though they would deem them too risky when considered in isolation. I suggest that a longtermist would—or at least should—evaluate risky polices in light of their prediction about future risks; hence, longtermism supports social risk-taking. I consider two formal versions of this argument, discuss the conditions needed for the arg…Read more
  •  58
    Why Offsetting is Not Like Shaking a Bag: A Reply to Barry & Cullity
    Ethics, Policy and Environment 26 (1): 144-148. 2023.
    1. Barry and Cullity (2022b) argue that when morally assessing a person’s climate actions,1 we should ask how these actions affect other people’s prospects.2 For the present purposes, we can unders...
  •  732
    Laurie Paul argues that, when it comes to many of your most significant life-changing decisions, the principles of rational choice are silent. That is because, in these cases, you anticipate that one of your choice options would yield a transformative experience. We argue that such decisions are best seen as ones in which you anticipate awareness growth. You do not merely lack knowledge about which possible outcome will arise from a transformative option; you lack knowledge about what are the po…Read more
  •  751
    Should I Offset or Should I Do More Good?
    Ethics, Policy and Environment 25 (3): 225-241. 2022.
    ABSTRACT Offsetting is a very ineffective way to do good. Offsetting your lifetime emissions may increase aggregated life expectancy by at most seven years, while giving the amount it costs to offset your lifetime emissions to a malaria charity saves in expectation the life of at least one child. Is there any moral reason to offset rather than giving to some charity that does good so much more effectively? There might be such a reason if your offsetting compensated or somehow benefitted the vict…Read more
  •  639
    The Economics and Philosophy of Risk
    In Conrad Heilmann & Julian Reiss (eds.), Routledge Handbook of Philosophy of Economics, Routledge. 2022.
    Neoclassical economists use expected utility theory to explain, predict, and prescribe choices under risk, that is, choices where the decision-maker knows---or at least deems suitable to act as if she knew---the relevant probabilities. Expected utility theory has been subject to both empirical and conceptual criticism. This chapter reviews expected utility theory and the main criticism it has faced. It ends with a brief discussion of subjective expected utility theory, which is the theory neocla…Read more
  •  26
    Can a knowledge threshold save the de minimis principle?
    Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability 236 (6): 1164-1167. 2022.
    The de minimis principle states that some risks are so trivial that they can be ignored or treated categorically differently from non-trivial risks. Lundgren and Stefánsson criticize the de minimis principle, arguing that it either has to be applied locally or globally and that problems arise whichever application is chosen. Aven and Seif respond to Lundgren and Stefánsson’s argument and defend the de minimis principle as a “meaningful and useful perspective for handling risk in practice.” The r…Read more
  •  1390
    Calibration dilemmas in the ethics of distribution
    Economics and Philosophy 39 (1): 67-98. 2023.
    This paper presents a new kind of problem in the ethics of distribution. The problem takes the form of several “calibration dilemmas,” in which intuitively reasonable aversion to small-stakes inequalities requires leading theories of distribution to recommend intuitively unreasonable aversion to large-stakes inequalities. We first lay out a series of such dilemmas for prioritarian theories. We then consider a widely endorsed family of egalitarian views and show that they are subject to even more…Read more
  •  44
    Collective Responses to Covid-19 and Climate Change
    with Andrea S. Asker and H. Orri Stefánsson
    Erasmus Journal for Philosophy and Economics 14 (1). 2021.
    Both individuals and governments around the world have willingly sacrificed a great deal to meet the collective action problem posed by Covid-19. This has provided some commentators with newfound hope about the possibility that we will be able to solve what is arguably the greatest collective action problem of all time: global climate change. In this paper we argue that this is overly optimistic. We defend two main claims. First, these two collective action problems are so different that the act…Read more
  •  573
    Economic policy evaluations require social welfare functions for variable-size populations. Two important candidates are critical-level generalized utilitarianism (CLGU) and rank-discounted critical-level generalized utilitarianism, which was recently characterized by Asheim and Zuber (2014) (AZ). AZ introduce a novel axiom, existence of egalitarian equivalence (EEE). First, we show that, under some uncontroversial criteria for a plausible social welfare relation, EEE suffices to rule out the Re…Read more
  •  856
    Continuity and catastrophic risk
    Economics and Philosophy 38 (2): 266-274. 2022.
    Suppose that a decision-maker's aim, under certainty, is to maximise some continuous value, such as lifetime income or continuous social welfare. Can such a decision-maker rationally satisfy what has been called "continuity for easy cases" while at the same time satisfying what seems to be a widespread intuition against the full-blown continuity axiom of expected utility theory? In this note I argue that the answer is "no": given transitivity and a weak trade-off principle, continuity for easy c…Read more
  •  1358
    The main aim of this book is to introduce the topic of limited awareness, and changes in awareness, to those interested in the philosophy of decision-making and uncertain reasoning.
  •  573
    What calibrating variable-value population ethics suggests
    with Dean Spears
    Economics and Philosophy 40 (3): 673-684. 2024.
    Variable-Value axiologies avoid Parfit’s Repugnant Conclusion while satisfying some weak instances of the Mere Addition principle. We apply calibration methods to two leading members of the family of Variable-Value views conditional upon: first, a very weak instance of Mere Addition and, second, some plausible empirical assumptions about the size and welfare of the intertemporal world population. We find that such facts calibrate these two Variable-Value views to be nearly totalist, and therefor…Read more
  •  1627
    The Repugnant Conclusion served an important purpose in catalyzing and inspiring the pioneering stage of population ethics research. We believe, however, that the Repugnant Conclusion now receives too much focus. Avoiding the Repugnant Conclusion should no longer be the central goal driving population ethics research, despite its importance to the fundamental accomplishments of the existing literature.
  •  1024
    Radical interpretation and decision theory
    with Anandi Hattiangadi and H. Orri Stefánsson
    Synthese 199 (3-4): 6473-6494. 2021.
    This paper takes issue with an influential interpretationist argument for physicalism about intentionality based on the possibility of radical interpretation. The interpretationist defends the physicalist thesis that the intentional truths supervene on the physical truths by arguing that it is possible for a radical interpreter, who knows all of the physical truths, to work out the intentional truths about what an arbitrary agent believes, desires, and means without recourse to any further empir…Read more
  •  442
    The Tragedy of the Risk Averse
    Erkenntnis 88 (1): 351-364. 2020.
    Those who are risk averse with respect to money, and thus turn down some gambles with positive monetary expectations, are nevertheless often willing to accept bundles involving multiple such gambles. Therefore, it might seem that such people should become more willing to accept a risky but favourable gamble if they put it in context with the collection of gambles that they predict they will be faced with in the future. However, it turns out that when a risk averse person adopts the long-term per…Read more
  •  628
    Catastrophic risk
    Philosophy Compass 15 (11): 1-11. 2020.
    Catastrophic risk raises questions that are not only of practical importance, but also of great philosophical interest, such as how to define catastrophe and what distinguishes catastrophic outcomes from non-catastrophic ones. Catastrophic risk also raises questions about how to rationally respond to such risks. How to rationally respond arguably partly depends on the severity of the uncertainty, for instance, whether quantitative probabilistic information is available, or whether only comparati…Read more
  •  1758
    The Bayesian maxim for rational learning could be described as conservative change from one probabilistic belief or credence function to another in response to newinformation. Roughly: ‘Hold fixed any credences that are not directly affected by the learning experience.’ This is precisely articulated for the case when we learn that some proposition that we had previously entertained is indeed true (the rule of conditionalisation). But can this conservative-change maxim be extended to revisi…Read more
  •  1010
    Population Ethics under Risk
    Social Choice and Welfare. forthcoming.
    Population axiology concerns how to evaluate populations in terms of their moral goodness, that is, how to order populations by the relations “is better than” and “is as good as”. The task has been to find an adequate theory about the moral value of states of affairs where the number of people, the quality of their lives, and their identities may vary. So far, this field has largely ignored issues about uncertainty and the conditions that have been discussed mostly pertain to the ranking of risk…Read more
  •  17
    Against the de minimis principle
    Risk Analysis 40 (5): 908-914. 2020.
    According to the class of de minimis decision principles, risks can be ignored (or at least treated very differently from other risks) if the risk is sufficiently small. In this article, we argue that a de minimis threshold has no place in a normative theory of decision making, because the application of the principle will either recommend ignoring risks that should not be ignored (e.g., the sure death of a person) or it cannot be used by ordinary bounded and information-constrained agents.
  •  1057
    Ambiguity Aversion behind the Veil of Ignorance
    Synthese 198 (7): 6159-6182. 2021.
    The veil of ignorance argument was used by John C. Harsanyi to defend Utilitarianism and by John Rawls to defend the absolute priority of the worst off. In a recent paper, Lara Buchak revives the veil of ignorance argument, and uses it to defend an intermediate position between Harsanyi's and Rawls' that she calls Relative Prioritarianism. None of these authors explore the implications of allowing that agent's behind the veil are averse to ambiguity. Allowing for aversion to ambiguity---which is…Read more
  •  1454
    On the Limits of the Precautionary Principle
    Risk Analysis 39 (6): 1204-1222. 2019.
    The Precautionary Principle (PP) is an influential principle of risk management. It has been widely introduced into environmental legislation, and it plays an important role in most international environmental agreements. Yet, there is little consensus on precisely how to understand and formulate the principle. In this paper I prove some impossibility results for two plausible formulations of the PP as a decision-rule. These results illustrate the difficulty in making the PP consistent with the …Read more