The paper discusses Ian Wells’s recent argument that there is a decision problem in which followers of Evidential Decision Theory end up poorer than followers of Causal Decision Theory despite having the same opportunities for money. It defends Evidential Decision Theory against Wells’s argument, on the following grounds. Wells's has not presented a decision problem in which his main claim is true. Four possible decision problems can be generated from his central example, in each of which followers of Evidential Decision (...) Theory do at least as well as followers of Causal Decision Theory. There is another case in which followers of Causal Decision Theory have the same opportunities for making money but end up worse than followers of Evidential Decision Theory. (shrink)

This paper argues that evidential decision theory is incompatible with options having objective values. If options have objective values, then it should always be rationally permissible for an agent to choose an option if they are certain that the option uniquely maximizes objective value. But, as we show, if options have objective values and evidential decision theory is true, then it is not always rationally permissible for an agent to choose an option if they are certain that the option uniquely (...) maximizes objective value. (shrink)

I begin with by discussing cases that seem to show that a range of norms – norms like Choose the best!, Believe the truth!, and even Keep your promises! – fail to map out an important part of normative space. At the core of the problem is the observation that in some cases we can only conform to these norms by luck, in a way that is not creditable to us. I outline a prevalent diagnosis of the problem of luck, (...) which I label perspectivist. According to this diagnosis, the problem with a range of objectivist norms is that they make reference to facts that may lie outside our perspectives, not being present to our minds. An agent’s perspective is a kind of representation of the world: her evidence, knowledge, beliefs, experiences, etc. The first aim of this paper is to argue that the perspectivist diagnosis of the problem of luck is not ultimately correct. The correct diagnosis, I argue, is feasibilist: in some situations it is not feasible to choose, act, or believe in ways that conformity to objectivist norms robustly depends on. That is, it is sometimes not feasible to manifest dispositions that robustly enough track what one ought to do or believe, according to norms like those listed above. The same, I argue, is true of perspectivist norms: sometimes it is not feasible to track facts about our own perspectives. This shift in focus from the limits of our perspectives to limits on what dispositions it is feasible to manifest has, I argue, deep ramifications for normative theory. My second aim is to sketch an alternative, feasibilist way of thinking about a more subject-directed kind of normativity, one that takes into account our limitations as human agents. The result is a normative picture that unifies the practical and theoretical domains. (shrink)

Newcomb’s Problem, Arif Ahmed (editor). Cambridge University Press, 2018, 233 pages.

A review of some major topics of debate in normative decision theory from circa 2007 to 2019. Topics discussed include the ongoing debate between causal and evidential decision theory, decision instability, risk-weighted expected utility theory, decision-making with incomplete preferences, and decision-making with imprecise credences.

Suppose that you have to take a test tomorrow but you do not want to study. Unfortunately you should study, since you care about passing and you expect to pass only if you study. Is there anything you can do to make it the case that you should not study? Is there any way for you to ‘rationalize’ slacking off? I suggest that such rationalization is impossible. Then I show that if evidential decision theory is true, rationalization is not only (...) possible but sometimes advisable. (shrink)

This paper develops a hybridization of Newcomb’s Problem and the Frustrater (Spencer and Wells’s 2019 paper ‘Why take both boxes?’), underscoring how difficult it is to reconcile the rationality of taking both boxes in Newcomb’s Problem and the rationality of taking the envelope in the Frustrater.

Our decision-theoretic states are not luminous. We are imperfectly reliable at identifying our own credences, utilities and available acts, and thus can never be more than imperfectly reliable at identifying the prescriptions of decision theory. The lack of luminosity affords decision theory a remarkable opportunity — to issue guidance on the basis of epistemically inaccessible facts. We show how a decision theory can guarantee action in accordance with contingent truths about which an agent is arbitrarily uncertain. It may seem that (...) such advantages would require dubiously adverting to externalist facts that go beyond the internalism of traditional decision theory, but this is not so. Using only the standard repertoire of decision-theoretic tools, we show how to modify existing decision theories to take advantage of this opportunity. These improved decision theories require agents to maximize conditional expected utility — expected utility conditional upon an agent’s actual decision situation. We call such modified decision theories ‘self-confident’. These self-confident decision theories have a distinct advantage over standard decision theories: their prescriptions are better. (shrink)

The nature of evidence is a problem for epistemology, but I argue that this problem intersects with normative decision theory in a way that I think is underappreciated. Among some decision theorists, there is a presumption that one can always ignore the nature of evidence while theorizing about principles of rational choice. In slogan form: decision theory only cares about the credences agents actually have, not the credences they should have. I argue against this presumption. In particular, I argue that (...) if evidence can be unspecific, then an alleged counterexample to causal decision theory fails. This implies that what theory of decision we think is true may depend on our opinions regarding the nature of evidence. Even when we are theorizing about subjective theories of rationality, we cannot set aside questions about the objective nature of evidence. (shrink)

Orthodox causal decision theory is unstable. Its advice changes as you make up your mind about what you will do. Several have objected to this kind of instability and explored stable alternatives. Here, I'll show that explorers in search of stability must part with a vestige of their homeland. There is no plausible stable decision theory which satisfies Savage's Sure Thing Principle. So those in search of stability must learn to live without it.

Evidential decision theory (EDT) says that the choiceworthiness of an option depends on its evidential connections to possible outcomes. Causal decision theory (CDT) holds that it depends on your beliefs about its causal connections. While Newcomb cases support CDT, Arif Ahmed has described examples that support EDT. A new account is needed to get all cases right. I argue that an option A's choiceworthiness is determined by the probability that a good outcome ensues at possible A‐worlds that match actuality in (...) the facts causally unaffected by your decision (the “unaffected facts”). Moreover, you should evaluate A on the assumption that A is compossible with the unaffected facts. This view entails that you should use EDT when evaluating A on the assumption that the unaffected facts determine your action, but use CDT when assessing A on the opposite assumption. A's choiceworthiness equals a weighted average of these conditional assessments. The weights are determined by your beliefs about whether the unaffected fact determine your action. This account gets both Newcomb and Ahmed cases right. According to an influential view, whether you take the unaffected facts to determine your action can make a difference to whether you can regard yourself as free and the action as being under your control. While my account is neutral on this issue, it entails that whether you take the unaffected facts to determine your action is important in a different way: it matters to whether you should follow EDT or CDT. (shrink)

In ‘An argument against causal decision theory’, Jack Spencer shows that standard formulations of causal decision theory run afoul of his Guaranteed Principle. In the sequential choice problem he employs to make this case, the transgression stems from an awkward discrepancy between how causalists typically value present vs future acts. This note suggests a version of causal decision theory that avoids this incongruity and so respects the Guaranteed Principle in Spencer’s problem. However, this formulation, and hence symmetric appraisal of present (...) and future acts, is also shown to be insufficient to secure causalist satisfaction of the Guaranteed Principle in general. (shrink)

In Necessary Existence, Pruss and Rasmussen give an argument for a necessary being employing a modest causal principle. Here I note that, when applied to highly general and fundamental matters, the principle may well be false (or at least not so obvious).

Seeking a decision theory that can handle both the Newcomb problems that challenge evidential decision theory and the unstable problems that challenge causal decision theory, some philosophers recently have turned to ‘graded ratifiability’. However, the graded ratifiability approach to decision theory is, despite its virtues, unsatisfactory; for it conflicts with the platitude that it is always rationally permissible for an agent to knowingly choose their best option.

According to ‘Excluders’, descriptive uncertainty – but not normative uncertainty – matters to what we ought to do. Recently, several authors have argued that those wishing to treat normative uncertainty differently from descriptive uncertainty face a dependence problem because one's descriptive uncertainty can depend on one's normative uncertainty. The aim of this paper is to determine whether the phenomenon of dependence poses a decisive problem for Excluders. I argue that existing arguments fail to show this, and that, while stronger ones (...) can be found, Excluders can escape them. (shrink)

This paper develops a form of moral actualism that can explain the procreative asymmetry. Along the way, it defends and explains the attractive asymmetry: the claim that although an impermissible option can be self-conditionally permissible, a permissible option cannot be self-conditionally impermissible.

This paper develops an argument against causal decision theory. I formulate a principle of preference, which I call the Guaranteed Principle. I argue that the preferences of rational agents satisfy the Guaranteed Principle, that the preferences of agents who embody causal decision theory do not, and hence that causal decision theory is false.

I present a decision problem in which causal decision theory appears to violate the independence of irrelevant alternatives (IIA) and normal-form extensive-form equivalence (NEE). I show that these violations lead to exploitable behavior and long-run poverty. These consequences appear damning, but I urge caution. This decision should lead causalists to a better understanding of what it takes for a decision between some collection of options to count as a subdecision of a decision between a larger collection of options. And with (...) this better understanding of subdecisions in hand, causalists will not violate the IIA or the NEE. This decision will also teach causalists that, in sequential decisions, a rational agent may be led to make a series of choices which are causally dominated by some other sequence of choices they could have made instead. I will encourage causalists to recognise this as an intrapersonal tragedy of the commons. (shrink)

Consequentialists often assume rational monism: the thesis that options are always made rationally permissible by the maximization of the selfsame quantity. This essay argues that consequentialists should reject rational monism and instead accept rational pluralism: the thesis that, on different occasions, options are made rationally permissible by the maximization of different quantities. The essay then develops a systematic form of rational pluralism which, unlike its rivals, is capable of handling both the Newcomb problems that challenge evidential decision theory and the (...) unstable problems that challenge causal decision theory. (shrink)

In the classic Miners case, an agent subjectively ought to do what they know is objectively wrong. This case shows that the subjective and objective ‘oughts’ are somewhat independent. But there remains a powerful intuition that the guidance of objective ‘oughts’ is more authoritative—so long as we know what they tell us. We argue that this intuition must be given up in light of a monotonicity principle, which undercuts the rationale for saying that objective ‘oughts’ are an authoritative guide for (...) agents and advisors. (shrink)

A choice function C is rational iff: if it allows a path through a sequence of decisions with a particular outcome, then that outcome is amongst the ones that C would have chosen from amongst all the possible outcomes of the sequence. This implies, and it is the strongest definition that implies, that anyone who is irrational could be talked out of their own preferences. It also implies weak but non-vacuous constraints on choices over ends. These do not include alpha (...) or beta. (shrink)

This paper presents a case for the claim that the infamous miners paradox is not a paradox. This contention is based on some important observations about the nature of ignorance with respect to both disjunctions and conditional obligations and their modal features. The gist of the argument is that given the uncertainty about the location of the miners in the story and the nature of obligations, the apparent obligation to block either mine shaft is cancelled.

Philosophers’ two favorite accounts of rational choice, Evidential Decision Theory (EDT) and Causal Decision Theory (CDT), each face a number of serious objections. Especially troubling are the recent charges that these theories are dynamically inconsistent. I note here that, under the epistemic assumptions that validate these charges, every decision theory that satisfies a pair of attractive postulates is doomed to a similar fate and then survey various lessons rational choice theorists might opt to draw from this.

In sequential decision problems, an act of learning cost-free evidence might be symptomatic, in the sense that performing this act itself provides evidence about states of the world it does nothing to causally promote. It is well known that orthodox causal decision theory, like its main rival evidential decision theory, may sanction such acts as rationally impermissible. This paper shows that, under plausible assumptions, a minimal version of ratificationist causal decision theory, known as principled ratificationism, fares better in this respect, (...) for it never labels symptomatic acts of learning cost-free evidence as rationally impermissible. (shrink)

Newcomb’s problem has spawned a debate about which variant of expected utility maximisation should guide rational choice. In this paper, we provide a new argument against what is probably the most popular variant: causal decision theory. In particular, we provide two scenarios in which CDT voluntarily loses money. In the first, an agent faces a single choice and following CDT’s recommendation yields a loss of money in expectation. The second scenario extends the first to a diachronic Dutch book against CDT.