In quantum domains, the measurement (or observation) of one of a pair of complementary variables introduces an unavoidable uncertainty in the value of that variable's complement. Such uncertainties are negligible in Newtonian worlds, where observations can be made without appreciably disturbing the observed system. Hence, one would not expect that an observation of a non-quantum probabilistic outcome could affect a probability distribution over subsequently possible states, in a way that would conflict with classical probability calculations. This paper examines three problems (...) in which observations appear to affect the probabilities and expected utilities of subsequent outcomes, in ways which may appear paradoxical. Deeper analysis of these problems reveals that the anomalies arise, not from paradox, but rather from faulty inferences drawn from the observations themselves. Thus the notion of ‘quantum’ decisiontheory is disparaged. (shrink)
This paper starts out from the proposition that case-based decisiontheory (CBDT) is an appropriate tool to explain human decision behavior in situations of structural ignorance. Although the developers of CBDT suggest its reality adequacy, CBDT has not yet been tested empirically very often, especially not in repetitive decision situations. Therefore, our main objective is to analyse the decision behavior of subjects in a repeated-choice experiment by comparing the explanation power of CBDT to reinforcement learning (...) and to classical decision criteria under uncertainty namely maximin, maximax, and pessimism-optimism. Our findings substantiate a predominant significantly higher validity of CBDT compared to the classical criteria and to reinforcement learning. For this reason, the experimental results confirm the suggested reality adequacy of CBDT in repetitive decision situations of structural ignorance. (shrink)
Research in psychology suggests that some individuals are more sensitive to positive than to negative information while others are more sensitive to negative rather than positive information. I take these cognitive positive–negative asymmetries in information processing to a Bayesian decision-theory model and explore its consequences in terms of decisions and payoffs. I show that in monotone decision problems economic agents with more positive-responsive information structures are always better off, ex ante, when they face problems where payoffs are (...) relatively more sensitive to the action chosen when the state of nature is favorable. (shrink)
In the last half century, decisiontheory has had a deep influence on moral theory. Its impact has largely been beneficial. However, it has also given rise to some problems, two of which are discussed here. First, issues such as risk-taking and risk imposition have been left out of ethics since they are believed to belong to decisiontheory, and consequently the ethical aspects of these issues have not been treated in either discipline. Secondly, ethics (...) has adopted the decision-theoretical idea that action-guidance has to be based on cause–effect or means–ends relationships between an individual action and its possible outcomes. This is problematic since the morally relevant connections between an action and future events are not fully covered by such relationships. In response to the first problem it is proposed that moral theory should deal directly and extensively with issues such as risk-taking and risk imposition, thereby intruding unabashedly into the traditional territory of decisiontheory. As a partial response to the second problem it is proposed that moral theorizing should release itself from the decision-theoretical requirement that the moral status of an action has to be derivable from the consequences (or other properties) that are assignable to that action alone. In particular, the effects that an action can have in combination with other actions by the same or other agents are valid arguments in an action-guiding moral discourse, even if its contribution to these combined consequences cannot be isolated and evaluated separately. (shrink)
Causal DecisionTheory (CDT) cares only about the effects of a contemplated act, not its causes. The paper constructs a case in which CDT consequently recommends a bet that the agent is certain to lose, rather than a bet that she is certain to win. CDT is plainly giving wrong advice in this case. It therefore stands refuted.
I argue that standard decision theories, namely causal decisiontheory and evidential decisiontheory, both are unsatisfactory. I devise a new decisiontheory, from which, under certain conditions, standard game theory can be derived.
This up-to-date introduction to decisiontheory offers comprehensive and accessible discussions of decision-making under ignorance and risk, the foundations of utility theory, the debate over subjective and objective probability, Bayesianism, causal decisiontheory, game theory, and social choice theory. No mathematical skills are assumed, and all concepts and results are explained in non-technical and intuitive as well as more formal ways. There are over 100 exercises with solutions, and a glossary of key (...) terms and concepts. An emphasis on foundational aspects of normative decisiontheory (rather than descriptive decisiontheory) makes the book particularly useful for philosophy students, but it will appeal to readers in a range of disciplines including economics, psychology, political science and computer science. • Has over 100 end of chapter review questions and exercises with solutions • Includes a chapter on how to draw a decision matrix • Explains the link between individual decision making, game theory and social choice theory Contents Preface; 1. Introduction; 2. The decision matrix; 3. Decisions under ignorance; 4. Decisions under risk; 5. Utility; 6. The mathematics of probability; 7. The philosophy of probability; 8. Why should we accept the preference axioms; 9. Causal vs. evidential decisiontheory; 10. Bayesian vs. non-Bayesian decisiontheory; 11. Game theory I: basic concepts and zero sum games; 12. Game theory II: nonzero sum and co-operative games; 13. Social choice theory; 14. Overview of descriptive decisiontheory; Appendix A. Glossary; Appendix B. Proof of the von Neumann-Morgenstern theorem; Further reading; Index. (shrink)
Decisiontheory is concerned with how agents should act when the consequences of their actions are uncertain. The central principle of contemporary decisiontheory is that the rational choice is the choice that maximizes subjective expected utility. This entry explains what this means, and discusses the philosophical motivations and consequences of the theory. The entry will consider some of the main problems and paradoxes that decisiontheory faces, and some of responses that can (...) be given. Finally the entry will briefly consider how decisiontheory applies to choices involving more than one agent. (shrink)
Decisiontheory is a theory of rationality, but the concept of rationality has several different dimensions. Making decisiontheory more realistic with respect to one dimension may well have the result of making it less realistic in another dimension. This paper illustrates this tension in the context of sequential choice. Trying to make decisiontheory more realistic by accommodating resoluteness and commitment brings the normative assessment dimension of rationality into conflict with the action-guiding (...) dimension. In the case of resolute choice the conflict comes because of a clash of perspectives. The perspective from which resolute choice seems normatively compelling is not the perspective from which it can serve the purpose of guiding action. (shrink)
The paper argues that on three out of five possible hypotheses about the Stern-Gerlach experiment we can construct novel and comparatively realistic decision problems on which (a) Causal decisionTheory and Evidential DecisionTheory conflict (b) Causal DecisionTheory and Quantum Mechanics conflict. It concludes that Causal DecisionTheory is false.
Andy Egan has recently produced a set of alleged counterexamples to causal decisiontheory (CDT) in which agents are forced to decide among causally unratifiable options, thereby making choices they know they will regret. I show that, far from being counterexamples, CDT gets Egan's cases exactly right. Egan thinks otherwise because he has misapplied CDT by requiring agents to make binding choices before they have processed all available information about the causal consequences of their acts. I elucidate CDT (...) in a way that makes it clear where Egan goes wrong, and which explains why his examples pose no threat to the theory. My approach has similarities to a modification of CDT proposed by Frank Arntzenius, but it differs in the significance that it assigns to potential regrets. I maintain, contrary to Arntzenius, that an agent facing Egan's decisions can rationally choose actions that she knows she will later regret. All rationality demands of agents it that they maximize unconditional causal expected utility from an epistemic perspective that accurately reflects all the available evidence about what their acts are likely to cause. This yields correct answers even in outlandish cases in which one is sure to regret whatever one does. (shrink)
An alleged counterexample to causal decisiontheory, put forward by Andy Egan, is studied in some detail. It is argued that Egan rejects the evaluation of causal decisiontheory on the basis of a description of the decision situation that is different from—indeed inconsistent with—the description on which causal decisiontheory makes its evaluation. So the example is not a counterexample to causal decisiontheory. Nevertheless, the example shows that causal (...) class='Hi'>decisiontheory can recommend unratifiable acts (acts that once decided upon appear sub-optimal) which presents a problem in the dynamics of intentions (as a decision is the forming of an intention to act). It is argued that we can defuse this problem if we hold that decisiontheory is a theory of rational decision making rather than a theory of rational acts. It is shown how decisions can have epistemic side-effects that are not mediated by the act and that there are cases where one can only bring oneself to perform the best act by updating by imaging rather than by conditioning . This provides a pragmatic argument for updating by imaging rather than by conditioning in these cases. (shrink)
The ontology of decisiontheory has been subject to considerable debate in the past, and discussion of just how we ought to view decision problems has revealed more than one interesting problem, as well as suggested some novel modifications of classical decisiontheory. In this paper it will be argued that Bayesian, or evidential, decision-theoretic characterizations of decision situations fail to adequately account for knowledge concerning the causal connections between acts, states, and outcomes (...) in decision situations, and so they are incomplete. Second, it will be argues that when we attempt to incorporate the knowledge of such causal connections into Bayesian decisiontheory, a substantial technical problem arises for which there is no currently available solution that does not suffer from some damning objection or other. From a broader perspective, this then throws into question the use of decisiontheory as a model of human or machine planning. (shrink)
The focus of this study is cognitive choice: the selection of one cognitive option (a hypothesis, a theory, or an axiom, for instance) rather than another. The study proposes that cognitive choice should be based on the plausibilities of states posited by rival cognitive options and the utilities of these options' information outcomes. The proposal introduces a form of decisiontheory that is novel because comparative; it permits many choices among cognitive options to be based on merely (...) comparative plausibilities and utilities. This form of decisiontheory intersects with recommendations by advocates of decisiontheory for cognitive choice, on the one hand, and defenders of comparative evaluation of scientific hypotheses and theories, on the other. But it differs from prior decision-theoretic proposals because it requires no more than minimal precision in specifying plausibilities and utilities. And it differs from comparative proposals because none has shown how comparative evaluations can be carried out within a decision-theoretic framework. (shrink)
In many forms of severe acute brain injury there is an early phase when prognosis is uncertain, followed later by physiological recovery and the possibility of more certain predictions of future impairment. There may be a window of opportunity for withdrawal of life support early, but if decisions are delayed there is the risk that the patient will survive with severe impairment. In this paper I focus on the example of neonatal encephalopathy and the question of the timing of prognostic (...) tests and decisions to continue or to withdraw life-sustaining treatment. Should testing be performed early or later; and how should parents decide what to do given the conflicting values at stake? I apply decisiontheory to the problem, using sensitivity analysis to assess how different features of the tests or different values would affect a decision to perform early or late prognostic testing. I draw some general conclusions from this model for decisions about the timing of testing in neonatal encephalopathy. Finally I consider possible solutions to the problem posed by the window of opportunity. Decisiontheory highlights the costs of uncertainty. This may prompt further research into improving prognostic tests. But it may also prompt us to reconsider our current attitudes towards the palliative care of newborn infants predicted to be severely impaired. (shrink)
We recast parts of decisiontheory in terms of channel theory concentrating on qualitative issues. Channel theory allows one to move between model theoretic and language theoretic notions as is necessary for an adequate covering. Doing so clarifies decisiontheory and presents the opportunity to investigate alternative formulations. As an example, we take some of Savage’s notions of decisiontheory and recast them within channel theory. In place of probabilities, we use (...) a particular logic of preference. We introduce a logic for describing actions separate from the logic of preference over actions. The structures introduced by channel theory that represent the decision problems can be seen to be an abstract framework. This frame-work is very accommodating to changing the nature of the decision problems to handle different aspects or theories about decision making. (shrink)
Is Bayesian decisiontheory a panacea for many of the problems in epistemology and the philosophy of science, or is it philosophical snake-oil? For years a debate had been waged amongst specialists regarding the import and legitimacy of this body of theory. Mark Kaplan had written the first accessible and non-technical book to address this controversy. Introducing a new variant on Bayesian decisiontheory the author offers a compelling case that, while no panacea, decision (...)theory does in fact have the most profound consequences for the way in which philosophers think about inquiry, criticism and rational belief. The new variant on Bayesian theory is presented in such a way that a non-specialist will be able to understand it. The book also offers new solutions to some classic paradoxes. It focuses on the intuitive motivations of the Bayesian approach to epistemology and addresses the philosophical worries to which it has given rise. (shrink)
In its classical conception, game theory aspires to be a determinate decisiontheory for games, understood as elements of a structurally specified domain. Its aim is to determine for each game in the domain a complete solution to each player's decision problem, a solution valid for all real-world instantiations, regardless of context. “Permissiveness” would constrain the theory to designate as admissible for a player any conjecture consistent with the solution function's designation of admissible strategies for (...) the other players. Given permissiveness and other appropriate constraints, solution sets must contain only Nash equilibria and at least one pure-strategy equilibrium, and there is no solution to games in which no symmetry invariant set of pure-strategy equilibria forms a Cartesian product. These results imply that the classical program is unrealizable. Moreover, the program is implicitly committed to permissiveness, through its common-knowledge assumptions and its commitment to equilibrium. The resulting incoherence deeply undermines the classical conception in a way that consolidates a long series of contextualist criticisms. (shrink)
We present a novel variant of decision making based on the mathematical theory of separable Hilbert spaces. This mathematical structure captures the effect of superposition of composite prospects, including many incorporated intentions, which allows us to describe a variety of interesting fallacies and anomalies that have been reported to particularize the decision making of real human beings. The theory characterizes entangled decision making, non-commutativity of subsequent decisions, and intention interference. We demonstrate how the violation of (...) the Savage’s sure-thing principle, known as the disjunction effect, can be explained quantitatively as a result of the interference of intentions, when making decisions under uncertainty. The disjunction effects, observed in experiments, are accurately predicted using a theorem on interference alternation that we derive, which connects aversion-to-uncertainty to the appearance of negative interference terms suppressing the probability of actions. The conjunction fallacy is also explained by the presence of the interference terms. A series of experiments are analyzed and shown to be in excellent agreement with a priori evaluation of interference effects. The conjunction fallacy is also shown to be a sufficient condition for the disjunction effect, and novel experiments testing the combined interplay between the two effects are suggested. (shrink)
The study of decision making has multiple implications for business ethics. This paper outlines some commonly used frameworks for understanding choice in business. It characterises the dominant model for business decision making as rational choice theory (RCT) and contrasts this with a more recent, naturalistic theory of decision-making, image theory. The implications of using RCT and image theory to model decision making are discussed with reference to three ethical systems. RCT is shown (...) to be consistent with Utilitarian ethics, but not with Kantian or Virtue-based ethics. Image theory is shown to be consistent with each. The paper identifies a number of implications following from this analysis. (shrink)
This paper discusses the philosophical argument and the application of the Triple Font Theory (TFT) for moral evaluation of human acts and attempts to integrate the conceptual components of major moral theories into a systematic internally consistent decision-making model that is theoretically driven. The paper incorporates concepts such as formal and material cooperation and the Principle of Double Effect (PDE) into the theoretical framework. It also advances the thesis that virtue theory ought to be included in any (...) adequate justification of morality and the need to integrate or coordinate notions of virtue into various act-oriented or principles-based ethics. The TFT offers a comprehensive and practical approach to ethical decision-making and is a useful alternative embedded in traditional wisdom. This paper provides a more general framework of the TFT than traditionally presented. Practical judgment is shown to play a constitute role in providing a guide for right action and is the “glue” that integrates the various components of the TFT. (shrink)
This paper provides new foundations for Bayesian DecisionTheory based on a representation theorem for preferences defined on a set of prospects containing both factual and conditional possibilities. This use of a rich set of prospects not only provides a framework within which the main theoretical claims of Savage, Ramsey, Jeffrey and others can be stated and compared, but also allows for the postulation of an extended Bayesian model of rational belief and desire from which they can be (...) derived as special cases. The main theorem of the paper establishes the existence of a such a Bayesian representation of preferences over conditional prospects, i.e. the existence of a pair of real-valued functions respectively measuring the agent’s degrees of belief and desire and which satisfy the postulated rationality conditions on partial belief and desire. The representation of partial belief is shown to be unique and that of partial desire, unique up to a linear transformation. (shrink)
Psychological theory and research in ethical decision making and ethical professional practice are presently hampered by a failure to take appropriate account of an extensive background in moral philosophy. As a result, attempts to develop models of ethical decision making are left vulnerable to a number of criticisms: that they neglect the problems of meta-ethics and the variety of meta-ethical perspectives; that they fail clearly and consistently to differentiate between descriptive and prescriptive accounts; that they leave unexplicated (...) the theoretical assumptions derived from the underlying moral theories; and that they fail to accommodate the complexity and comprehensiveness of the processes involved in the making and implementing of ethical decisions. Many of these problems also have implications for the methodological domain. This paper offers an analysis of the difficulties, and makes a number of recommendations for future theory, research and practical applications, including: the need for training in moral philosophy; clarification of the status of Professional Codes in decisional models; the development of theoretically comprehensive prescriptive models; and the testing of these models in ways that do justice to their dimensional scope and theoretical complexity. (shrink)
The first part of this paper reexamines the logical foundations of Bayesian decisiontheory and argues that the Bayesian criterion of expected-utility maximization is the only decision criterion consistent with rationality. On the other hand, the Bayesian criterion, together with the Pareto optimality requirement, inescapably entails a utilitarian theory of morality. The next sections discuss the role both of cardinal utility and of cardinal interpersonal comparisons of utility in ethics. It is shown that the utilitarian welfare (...) function satisfies all of Arrow's social choice postulates avoiding the celebrated impossibility theorem by making use of information which is unavailable in Arrow's original framework. Finally, rule utilitarianism is contrasted with act utilitarianism and judged to be preferable for the purposes of ethical theory. (shrink)
In general, the technical apparatus of decisiontheory is well developed. It has loads of theorems, and they can be proved from axioms. Many of the theorems are interesting, and useful both from a philosophical and a practical perspective. But decisiontheory does not have a well agreed upon interpretation. Its technical terms, in particular, ‘utility’ and ‘preference’ do not have a single clear and uncontroversial meaning.How to interpret these terms depends, of course, on what purposes (...) in pursuit of which one wants to put decisiontheory to use. One might want to use it as a model of economic decision-making, in order to predict the behavior of corporations or of the stock market. In that case, it might be useful to interpret the technical term ‘utility’ as meaning money profit. Decisiontheory would then be an empirical theory. I want to look into the question of what ‘utility’ could mean, if we want decisiontheory to function as a theory of practical rationality. I want to know whether it makes good sense to think of practical rationality as fully or even partly accounted for by decisiontheory. I shall lay my cards on the table: I hope it does make good sense to think of it that way. For, I think, if Humeans are right about practical rationality, then decisiontheory must play a very large part in their account. And I think Humeanism has very strong attractions. (shrink)
Since the middle of this century, the dominant prescriptive approach to decisiontheory has been a deductive viewpoint which is concerned with axioms of rational preference and their consequences. After summarizing important problems with the preference primitive, this paper argues for a constructive approach in which information is the foundation for decision-making. This approach poses comparability of uncertain acts as a question rather than an assumption. It is argued that, in general, neither preference nor subjective probability can (...) be assumed given, and that these need to be generated by using the relevant information available to the decision-agent in a given situation. A specific constructive model is discussed and illustrated with a real example from this viewpoint. (shrink)
A new axiomatic basis for the foundations of decisiontheory is introduced and its mathematical development outlined. The system combines direct intuitive operational appeal with considerable structural flexibility in the resulting mathematical framework.
Zeleny's recent conjecture that multi-attribute decisiontheory may help to overcome the inadequacies of the linear regression model is incorrect. Recognition of the information processing advantages inherent in multiple -attribute decision situations combined with a requirement of transitivity itself implies linear objective functions. This follows from some recent developments by a psychologist and an economist in the analysis of individual and collective decision processes, developments which do not take as their starting point the paradigm of choice (...) offered in utility theory. (shrink)
The New Economic Windows Series, derived from Massimo Salzano's ideas and work, incorporates material from textbooks, monographs and conference proceedings that deals with both the theoretical and applied aspects of various sub-disciplines ...
The theory of Markov decision processes (MDP) can be used to analyze a wide variety of stopping time problems in economics. In this paper, the nature of such problems is discussed and then the underlying theory is applied to the question of arranged marriages. We construct a stylized model of arranged marriages and, inter alia, it is shown that a decision maker's optimal policy depends only on the nature of the current marriage proposal, independent of whether (...) there is recall (storage) of previous marriage proposals. (shrink)
Following Kuhn's main thesis according to which theory revision and acceptance is always paradigm relative, I propose to outline some possible consequences of such a view. First, asking the question in what sense Bayesian decisiontheory could serve as the appropriate (normative) theory of rationality examined from the point of view of the epistemology of theory acceptance, I argue that Bayesianism leads to a narrow conception of theory acceptance. Second, regarding the different types of (...)theory revision, i. e. expansion, contraction, replacement and residuals shifts, I extract from Kuhn's view a series of indications showing that theory replacement cannot be rationalized within the framework of Bayesian deciston theory, not even within a more sophisticated version of that model. Third, and finally, I will point to the need for a more comprehensive model of rationality than the Bayesian expected utility maximization model, the need for a model which could better deal with the different aspects of theory replacement. I will show that Kuhn's distinction between normal and revolutionary science gives us several hints for a more adequate theory of rationality in science. I will also show that Kuhn is not in a position to fully articulate his main ideas and that he well be confronted with a serious problem concerning collective choice of a paradigm. (shrink)
This book is a unique introductory overview of decisiontheory. It is completely non-technical, without a single formula in the book. Written in a crisp and clear style it succinctly covers the full range of philosophical issues of rationality and decisiontheory, including game theory, social choice theory, prisoner's dilemma and much else. The book aims to expand the scope and enrich the foundations of decisiontheory. By addressing such issues as ambivalence, (...) inner conflict, and the constraints imposed upon us by our attachments to others, Frederic Schick reveals that our thinking is often more subtle than standard theories of rationality allow. Only a theory that respects that subtlety can illumine what is otherwise puzzling. The book contains many examples drawn from history and literature dealing with subjects such as love, war, friendship, and crime. (shrink)
Decision making theory in general, and mental models in particular, associate judgment and choice. Decision choice follows probability estimates and errors in choice derive mainly from errors in judgment. In the studies reported here we use the Monty Hall dilemma to illustrate that judgment and choice do not always go together, and that such a dissociation can lead to better decision-making. Specifically, we demonstrate that in certain decision problems, exceeding working memory limitations can actually improve (...)decision choice. We show across four experiments that increasing the number of choice alternatives forces people to collapse choices together, resulting in better decision-making. While choice performance improves, probability judgments do not change, thus demonstrating an important dissociation between choice and probability judgments. We propose the Collapsing Choice Theory (CCT) which explains how working memory capacity, probability estimation, choice alternatives, judgment, and regret all interact and effect decision quality. (shrink)
Incorporation of the behavioral issues of the decision maker (DM) is among the aspects that each Multicriteria Decision Making (MCDM) method implicitly or explicitly takes into account. As postulated by regret theory, the feelings of regret and rejoice are among the behavioral issues associated with the entire decision making process. Within the context of MCDM, the DM may feel regret, when the chosen alternative is compared with another one having at least one better criterion value. PROMETHEE (...) II is a widely known MCDM method that makes no explicit incorporation of regret attitude of the DM. In this paper, we elaborate on the applicability of regret theory to MCDM context. In particular, we investigate the findings of regret theory and explore the parallel between regret theory and PROMETHEE II method. Relying on the concepts of regret theory, we demonstrate how a decision that is made using a PROMETHEE II based outranking method conforms to the regret attitude of the DM. (shrink)
Some decisions result in cognitive consequences such as information gained and information lost. The focus of this study, however, is decisions with consequences that are partly or completely noncognitive. These decisions are typically referred to as ‘real-life decisions’. According to a common complaint, the challenges of real-life decision making cannot be met by decisiontheory. This complaint has at least two principal motives. One is the maximizing objection that to require agents to determine the optimal act under (...) real-world constraints is unrealistic. The other is the precision objection that the numeric requirements for applying decisiontheory are overly demanding for real-life decisions. Responses to both objections are aired in the History section of this chapter. The maximizing objection is addressed with reference to work by Weirich and Pollock, while the precision objection is countered via a proposal by Kyburg and another by Gärdenfors and Sahlin. However, the Current Research section urges a different response to the precision objection by introducing a comparative version of decisiontheory. Drawing on Chu and Halpern’s notion of generalized expected utility, this version of decisiontheory permits many choices to be based on merely comparative plausibilities and utilities. Finally, the Further Research section undertakes an open-ended exploration of three of the assumptions upon which this form of decisiontheory (and many others) is based: transitivity, independence, and plausibilistic decision rules. (shrink)
A simple two-choice single outcome valued decision under risk is presented which should show up the limitations in the classical approach of von Neumann, its extensions and its alternatives. An empirical testing of this hypothesis strongly supports this criticism. A rationale for explaining the apparent ‘irrational decision’ is put forward and the case is made for understanding the relative nature of decision choices especially when multi-criteria are involved.
Newcomb's problem and similar cases show the need to incorporate causal distinctions into the theory of rational decision; the usual noncausal decisiontheory, though simpler, does not always give the right answers. I give my own version of causal decisiontheory, compare it with versions offered by several other authors, and suggest that the versions have more in common than meets the eye.
Representation theorems are often taken to provide the foundations for decisiontheory. First, they are taken to characterize degrees of belief and utilities. Second, they are taken to justify two fundamental rules of rationality: that we should have probabilistic degrees of belief and that we should act as expected utility maximizers. We argue that representation theorems cannot serve either of these foundational purposes, and that recent attempts to defend the foundational importance of representation theorems are unsuccessful. As a (...) result, we should reject these claims, and lay the foundations of decisiontheory on firmer ground. (shrink)
The purpose of this paper is to show how some of the controversial questions concerning utilitarianism can be clarified by the modelling techniques and the other analytical tools of decisiontheory (and, sometimes, of game theory). It is suggested that the moral rules of utilitarian ethics have a logical status similar to that of the normative rules (theorems) of such formal normative disciplines as decisiontheory and game theory.The paper argues that social utility should (...) be defined, not in hedonistic or in ideal-utilitarian terms, but rather in terms of individual preferences, in accordance with the author's equiprobability model of moral value judgments. (shrink)
Many philosophers (myself included) have been converted to causal decisiontheory by something like the following line of argument: Evidential decisiontheory endorses irrational courses of action in a range of examples, and endorses “an irrational policy of managing the news”. These are fatal problems for evidential decisiontheory. Causal decisiontheory delivers the right results in the troublesome examples, and does not endorse this kind of irrational news-managing. So we should give (...) up evidential decisiontheory, and be causal decision theorists instead. Unfortunately, causal decisiontheory has its own family of problematic examples for which it endorses irrational courses of action, and its own irrational policy that it is committed to endorsing. These are, I think, fatal problems for causal decisiontheory. I wish that I had another theory to offer in its place. (shrink)
has offered evidential decision theorists a defence against the charge that they make unintuitive recommendations for cases like Newcomb's Problem. He says that when conditional probabilities are assessed from the agent's point of view, evidential decisiontheory makes the same recommendation as intuition. I argue that calculating the probabilities in Price's way leads to no recommendation. It condemns the agent to perpetual oscillation between different options. Price's Argument Instability Objections Conclusion.
This paper has as its topic two recent philosophical disputes. One of these disputes is internal to the project known as decisiontheory, and while by now familiar to many, may well seem to be of pressing concern only to specialists. It has been carried on over the last twenty years or so, but by now the two opposing camps are pretty well entrenched in their respective positions, and the situation appears to many observers (as well as to (...) some of the parties involved) to have reached a sort of stalemate. The second of these two disputes is, on the other hand, very much alive. While it has been framed in decision theoretic terms, it is definitely not a dispute internal to that enterprise. It is, rather, a debate about the very coherence of the notion of objective value, and as such touches on issues of central importance to, for example, meta–ethics and moral psychology. (shrink)
You are given a choice between two envelopes. You are told, reliably, that each envelope has some money in it—some whole number of dollars, say—and that one envelope contains twice as much money as the other. You don’t know which has the higher amount and which has the lower. You choose one, but are given the opportunity to switch to the other. Here is an argument that it is rationally preferable to switch: Let x be the quantity of money in (...) your chosen envelope. Then the quantity in the other is either 1/2x or 2x, and these possibilities are equally likely. So the expected utility of switching is 1/2(1/2x) + 1/2(2x) = 1.25x, whereas that for sticking is only x. So it is rationally preferable to switch. There is clearly something wrong with this argument. For one thing, it is obvious that neither choice is rationally preferable to the other: it’s a tossup. For another, if you switched on the basis of this reasoning, then the same argument could immediately be given for switching back; and so on, indefinitely. For another, there is a parallel argument for the rational preferability of sticking, in terms of the quantity y in the other envelope. But the problem is to provide an adequate account of how the argument goes wrong. This is the two envelope paradox. In an earlier paper Horgan 2000) I offered a diagnosis of the paradox. I argued that the flaw in the argument is considerably more subtle and interesting than is usually believed, and that an adequate diagnosis reveals important morals about both probability and the foundations of decisiontheory. One moral is that there is a kind of expected utility, not previously noticed as far as I know, that I call nonstandard expected utility. I proposed a general normative principle governing the proper application of nonstandard expected utility in rational decisionmaking. But this principle is inadequate in several respects, some of which I acknowledged in note added in press and some of which I have meanwhile discovered.. (shrink)
On the face of it, ethics and decisiontheory give quite different advice about what the best course of action is in a given situation. In this paper we examine this alleged conflict in the realm of environmental decision-making. We focus on a couple of places where ethics and decisiontheory might be thought to be offering conflicting advice: environmental triage and carbon trading. We argue that the conflict can be seen as conflicts about other (...) things (like appropriate temporal scales for value assignments, idealisations of the decision situation, whether the conservation budget really is fixed and the like). The good news is that there is no conflict between decisiontheory and environmental ethics. The bad news is that a great deal of environmental decision modelling may be rather simple minded, in that it does not fully incorporate some of these broader issues about temporal scales and the dynamics of many of the decision situations. (shrink)