H. Orri Stefansson

Stockholm University
Institute for Futures Studies
  •  199
    Fair Chance and Modal Consequentialism
    Economics and Philosophy 31 (3): 371-395. 2015.
    This paper develops a Multidimensional Decision Theory and argues that it better captures ordinary intuitions about fair distribution of chances than classical decision theory. The theory is an extension of Richard Jeffrey’s decision theory to counterfactual prospects and is a form of Modal Consequentialism, according to which the value of actual outcomes often depends on what could have been. Unlike existing versions of modal consequentialism, the multidimensional decision theory allows us to e…Read more
  •  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
  •  158
    Epistemic Transformation and Rational Choice
    Economics and Philosophy 33 (1): 125-138. 2017.
    L. A. Paul has recently argued that the epistemically transformative nature of certain experiences makes it impossible to rationally decide whether to have the experience or not. We start by explaining why, contrary to what Paul claims, epistemically transformative experiences do not pose a general problem for the possibility of rational choice. However, we show there is a particular type of agent for whom the problem identified by Paul does arise. With this agent in mind, we examine Paul’s own …Read more
  •  157
    What is "real" in Probabilism?
    Australasian Journal of Philosophy 95 (3): 573-587. 2017.
    This paper defends two related claims about belief. First, the claim that unlike numerical degrees of belief, comparative beliefs are primitive and psychologically real. Second, the claim that the fundamental norm of Probabilism is not that numerical degrees of belief should satisfy the probability axioms, but rather that comparative beliefs should satisfy certain constraints.
  •  128
    Desires, beliefs and conditional desirability
    Synthese 191 (16): 4019-4035. 2014.
    Does the desirability of a proposition depend on whether it is true? Not according to the Invariance assumption, held by several notable philosophers. The Invariance assumption plays an important role in David Lewis’ famous arguments against the so-called Desire-as-Belief thesis (DAB), an anti-Humean thesis according to which a rational agent desires a proposition exactly to the degree that she believes the proposition to be desirable. But the assumption is of interest independently of Lewis’ ar…Read more
  •  100
    On the Ratio Challenge for Comparativism
    Australasian Journal of Philosophy 96 (2): 380-390. 2018.
    This paper discusses a challenge for Comparativists about belief, who hold that numerical degree of belief (in particular, subjective probability) is a useful fiction, unlike comparative belief, which they regard as real. The challenge is to make sense of claims like ‘I am twice as confident in A as in B’ in terms of comparative belief only. After showing that at least some Comparativists can meet this challenge, I discuss implications for Zynda’s [2000] and Stefánsson’s [2017] defences of Compa…Read more
  •  99
    Humean Supervenience and Multidimensional Semantics
    Erkenntnis 79 (6): 1391-1406. 2014.
    What distinguishes indicative conditionals from subjunctive conditionals, according to one popular view, is that the so-called Adams’ thesis holds for the former kind of conditionals but the so-called Skyrms’ thesis for the latter. According to a plausible metaphysical view, both conditionals and chances supervene on non-modal facts. But since chances do not supervene on facts about particular events but facts about event-types, the past as well as the future is chancy. Some philosophers have wo…Read more
  •  88
    Gambling with Death
    Topoi 39 (2): 271-281. 2020.
    Orthodox expected utility theory imposes too stringent restrictions on what attitudes to risk one can rationally hold. Focusing on a life-and-death gamble, I identify as the main culprit the theory’s Linearity property, according to which the utility of a particular change in the risk of a bad outcome is independent of the original level of risk. Finally, I argue that a recent non-standard Bayesian decision theory, that does not have this property, handles risky gambles better than the orthodox …Read more
  •  75
    Desirability of conditionals
    Synthese 193 (6): 1967-1981. 2016.
    This paper explores the different ways in which conditionals can be carriers of good and bad news. I suggest a general measure of the desirability of conditionals, and use it to explore the different ways in which conditionals can have news value. I conclude by arguing that the desirability of a counterfactual conditional cannot be reduced to the desirability of factual propositions.
  •  68
    A Lewisian Trilemma
    Ratio 27 (3): 262-275. 2013.
    According to one reading of the thesis of Humean Supervenience, most famously defended by David Lewis, certain ‘fundamental’ (non-modal) facts entail all there is but do not supervene on less fundamental facts. However, in this paper I prove that it follows from Lewis' possible world semantics for counterfactuals, in particular his Centring condition, that all non-modal facts supervene on counterfactuals. Humeans could respond to this result by either giving up Centring or abandoning the idea th…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...
  •  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
  •  54
  •  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
  •  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
  •  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
  •  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.