Abstract In this paper, I argue that the traditional philosophical approach of taking cognitively and emotionally competent adult people to be the prototypical instances of agency should be revised in light of current work in the behavioral sciences. Logical consistency in application is better served by taking simple goal-directed and feedback-governed systems such as insects as the prototypes of the concept of agency, with people being agents ?by extension? in the same sense as countries or corporations.

This encyclopedia entry urges what it takes to be correctives to common (mis)understandings concerning the phenomenon of incommensurability and incomparability and briefly outlines some of their philosophical upshots.

This dissertation looks at a set of interconnected questions concerning the foundations of probability, and gives a series of interconnected answers. At its core is a piece of old-fashioned philosophical analysis, working out what probability is. Or equivalently, investigating the semantic question of what is the meaning of ‘probability’? Like Keynes and Carnap, I say that probability is degree of reasonable belief. This immediately raises an epistemological question, which degrees count as reasonable? To solve that in its full generality would (...) mean the end of human inquiry, so that won’t be attempted here. Rather I will follow tradition and merely investigate which sets of partial beliefs are coherent. -/- The standard answer to this question, what is commonly called the Bayesian answer, says that degrees of belief are coherent iff they form a probability function. I disagree with the way this is usually justified, but subject to an important qualification I accept the answer. The important qualification is that degrees of belief may be imprecise, or vague. Part one of the dissertation, chapters 1 to 6, looks largely at the consequences of this qualification for the semantic and epistemological questions already mentioned. It turns out that when we allow degrees of belief to be imprecise, we can discharge potentially fatal objections to some philosophically attractive theses. Two of these, that probability is degree of reasonable belief and that the probability calculus provides coherence constraints on partial beliefs, have been mentioned. Others include the claim, defended in chapter 4, that chance is probability given total history. -/- As well as these semantic and epistemological questions, studies of the foundations of probability usually include a detailed discussion of decision theory. For reasons set out in chapter 2, I deny we can gain epistemological insights from decision theory. Nevertheless, it is an interesting field to study on its own, and it might be expected that there would be decision theoretic consequences of allowing imprecise degrees of belief. As I show in part two, this expectation seems to be mistaken. Chapter 9 shows that there aren’t interesting consequences of this theory for decision theory proper, and chapters 10 and 11 show that Keynes’s attempt to use imprecision in degrees of belief to derive a distinctive theory of interest rates is unsound. -/- Chapters 7 and 8 provide a link between these two parts. In chapter 7 I look at some previous philosophical investigations into the effects of imprecision. In chapter 8 I develop what I take to be the best competitor to the theory defended here – a constructivist theory of probability. On this view degrees of belief are precise, but the relevant coherence constraint is a constructivist probability calculus. This view is, I think, mistaken, but the calculus has some intrinsic interest, and there are at least enough arguments for it to warrant a chapter-length examination. (shrink)

Probabilistic coherence is not an absolute requirement of rationality; nevertheless, it is an ideal of rationality with substantive normative import. An idealized rational agent who avoided making implicit logical errors in forming his preferences would be coherent. In response to the challenge, recently made by epistemologists such as Foley and Plantinga, that appeals to ideal rationality render probabilism either irrelevant or implausible, I argue that idealized requirements can be normatively relevant even when the ideals are unattainable, so long as they (...) define a structure that links imperfect and perfect rationality in a way that enables us to make sense of the notion of better approximations to the ideal. I then analyze the notion of approximation to the ideal of coherence by developing a generalized theory of belief functions that allows for incoherence, and showing how such belief functions can be ordered with regard to greater or lesser coherence. (shrink)

What distinguishes preference utilitarianism from other utilitarian positions is the axiological component: the view concerning what is intrinsically valuable. According to PU, intrinsic value is based on preferences. Intrinsically valuable states are connected to our preferences being satisfied.

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 decision theory that is novel because comparative; it permits many choices among cognitive options to be based on merely comparative plausibilities and (...) utilities. This form of decision theory intersects with recommendations by advocates of decision theory 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)

Against the contention of David Lewis Philosophy and Public Affairs 8, 235–240, that the Prisoner’s Dilemma is a Newcomb Problem, José Luis Bermúdez Analysis 73, 423–429, has urged that Lewis’s assimilation removes the very outcome scenarios that make the Dilemma so puzzling. I objected that this criticism of Lewis presupposes that the Dilemma is harder to resolve than Newcomb’s Problem, in effect challenging Bermúdez to justify this assumption. In his 2015 he takes up the challenge, arguing that while the former (...) presents a problem of strategic choice the latter is problem of parametric choice. I argue here that appeal to the distinction between these two kinds of choice cannot sustain the rejection of Lewis’s view. (shrink)

The claim that (OIC) “ought” implies “can” (i.e., you have an obligation only at times at which you can obey it) entails that (1) obligations that become infeasible are lost (i.e., you stop having an obligation when you become unable to obey it). Moreover, the claim that (2) obligations that become overridden are not always lost (i.e., sometimes you keep having an obligation when you acquire a stronger incompatible obligation) entails that (ONIM) “ought” does not imply “must” (i.e., some obligations (...) are not all-things-considered). It is standard to infer ONIM—via (2)—from the premise that becoming overridden can result in “moral residue” (e.g., in the appropriateness of feeling regret). But then, I note, one could similarly infer not-OIC—via not-(1)—from the premise that becoming infeasible can result in moral residue. So there is an argument against OIC which parallels the standard argument for ONIM. I respond by rejecting both arguments: it is a mistake to always infer from the presence of moral residue that an obligation is not lost. Then I propose new arguments both for ONIM and for OIC. (shrink)

This paper investigates the relation between consequentialism, as conceived of in moral theory, and standard expected utility theory. I argue that there is a close connection between the two. I show furthermore that consequentialism is not neutral with regard to the values of the agent. Consequentialism, as well as standard expected utility theory, is incompatible with the recognition of considerations that depend on what could have been the case, such as regret and disappointment. I conclude that consequentialism should be rejected (...) as a principle of rational choice and that there are reasons to doubt its plausibility in the realm of moral theory. Moreover, this is a reason to doubt whether standard expected utility theory is a plausible theory of rational choice. (shrink)

When thinking about ethics, technology is often only mentioned as the source of our problems, not as a potential solution to our moral dilemmas. When thinking about technology, ethics is often only mentioned as a constraint on developments, not as a source and spring of innovation. In this paper, we argue that ethics can be the source of technological development rather than just a constraint and technological progress can create moral progress rather than just moral problems. We show this by (...) an analysis of how technology can contribute to the solution of so-called moral overload or moral dilemmas. Such dilemmas typically create a moral residue that is the basis of a second-order principle that tells us to reshape the world so that we can meet all our moral obligations. We can do so, among other things, through guided technological innovation. (shrink)

It is a familiar argument that advocates accommodating the so-called paradoxes of decision theory by abandoning the “independence” postulate. After all, if we grant that choice reveals preference, the anomalous choice patterns of the Allais and Ellsberg problems violate postulate P2 of Savage's system. The strategy of making room for new preference patterns by relaxing independence is adopted in each of the following works: Samuelson, Kahneman and Tversky's “Prospect Theory”, Allais and Hagen, Fishburn, Chew and MacCrimmon, McClennen, and in closely (...) argued essays by Machina. (shrink)

There are at least two plausible generalisations of subjective expected utility (SEU) theory: cumulative prospect theory (which relaxes the independence axiom) and Levi’s decision theory (which relaxes at least ordering). These theories call for a re-assessment of the minimal requirements of rational choice. Here, I consider how an analysis of sequential decision making contributes to this assessment. I criticise Hammond’s (Economica 44(176):337–350, 1977; Econ Philos 4:292–297, 1988a; Risk, decision and rationality, 1988b; Theory Decis 25:25–78, 1988c) ‘consequentialist’ argument for the SEU (...) preference axioms, but go on to formulate a related diachronic-Dutch-book-style’ argument that better achieves Hammond’s aims. Some deny the importance of Dutch-book sure losses, however, in which case, Seidenfeld’s (Econ Philos 4:267–290, 1988a) argument that distinguishes between theories that relax independence and those that relax ordering is relevant. I unravel Seidenfeld’s argument in light of the various criticisms of it and show that the crux of the argument is somewhat different and much more persuasive than what others have taken it to be; the critical issue is the modelling of future choices between ‘indifferent’ decision-tree branches in the sequential setting. Finally, I consider how Seidenfeld’s conclusions might nonetheless be resisted. (shrink)

The question of how the probabilistic opinions of different individuals should be aggregated to form a group opinion is controversial. But one assumption seems to be pretty much common ground: for a group of Bayesians, the representation of group opinion should itself be a unique probability distribution, 410–414, [45]; Bordley Management Science, 28, 1137–1148, [5]; Genest et al. The Annals of Statistics, 487–501, [21]; Genest and Zidek Statistical Science, 114–135, [23]; Mongin Journal of Economic Theory, 66, 313–351, [46]; Clemen and (...) Winkler Risk Analysis, 19, 187–203, [7]; Dietrich and List [14]; Herzberg Theory and Decision, 1–19, [28]). We argue that this assumption is not always in order. We show how to extend the canonical mathematical framework for pooling to cover pooling with imprecise probabilities by employing set-valued pooling functions and generalizing common pooling axioms accordingly. As a proof of concept, we then show that one IP construction satisfies a number of central pooling axioms that are not jointly satisfied by any of the standard pooling recipes on pain of triviality. Following Levi, 3–11, [39]), we also argue that IP models admit of a much better philosophical motivation as a model of rational consensus. (shrink)

I focus my discussion on the well-known Ellsberg paradox. I find good normative reasons for incorporating non-precise belief, as represented by sets of probabilities, in an Ellsberg decision model. This amounts to forgoing the completeness axiom of expected utility theory. Provided that probability sets are interpreted as genuinely indeterminate belief, such a model can moreover make the “Ellsberg choices” rationally permissible. Without some further element to the story, however, the model does not explain how an agent may come to have (...) unique preferences for each of the Ellsberg options. Levi holds that the extra element amounts to innocuous secondary “risk” or security considerations that are used to break ties when more than one option is rationally permissible. While I think a lexical choice rule of this kind is very plausible, I argue that it involves a greater break with xpected utility theory than mere violation of the ordering axiom. (shrink)

This paper studies a generalization of rational choice theory. I briefly review the motivations that Helzner gives for his conditional choice construction . Then, I focus on the important class of conditional choice functions with vacuous second tiers. This class is interesting for both formal and philosophical reasons. I argue that this class makes explicit one of conditional choice’s normative motivations in terms of an account of neutrality advocated within a certain tradition in decision theory. The observations recorded—several of which (...) are generalizations of central results in the standard theory of rational choice—are intended to provide further insight into how conditional choice generalizes the standard account and are offered as additional evidence of the fruitfulness of the conditional choice framework. (shrink)

The paper will show how one may rationalize one-boxing in Newcomb's problem and drinking the toxin in the Toxin puzzle within the confines of causal decision theory by ascending to so-called reflexive decision models which reflect how actions are caused by decision situations (beliefs, desires, and intentions) represented by ordinary unreflexive decision models.

An organizing framework is set out for the diverse literature on business ethics in relation to strategic management. It consists of sets of bi-polar components, spanning themes and topical themes, with a derived typology of contributions. Then, in the spirit of classical pragmatism, the organizing framework is re-cast as an integrative conceptual model of the strategy–ethics relationship. The approach recognizes that both pragmatism and dialectics can underpin progress towards integration, encompassing both normative and empirical aspects.

We discuss several features of coherent choice functions—where the admissible options in a decision problem are exactly those that maximize expected utility for some probability/utility pair in fixed set S of probability/utility pairs. In this paper we consider, primarily, normal form decision problems under uncertainty—where only the probability component of S is indeterminate and utility for two privileged outcomes is determinate. Coherent choice distinguishes between each pair of sets of probabilities regardless the “shape” or “connectedness” of the sets of probabilities. (...) We axiomatize the theory of choice functions and show these axioms are necessary for coherence. The axioms are sufficient for coherence using a set of probability/almost-state-independent utility pairs. We give sufficient conditions when a choice function satisfying our axioms is represented by a set of probability/state-independent utility pairs with a common utility. (shrink)

In this article, monist values are expressed as preferences like in economics and decision making. On the basis of this formalization, various ways of defining value disagreement of agents within a group are investigated. Twelve notions of categorical value disagreement are laid out. Since these are too coarse-grained for many purposes, known distance-based approaches like Kendall’s Tau and Spearman’s footrule are generalized from linear orders to preorders and position-sensitive variants are developed. The account is further generalized to allow for agents (...) with incomplete information. The article ends with a discussion of known limitations of preference-based accounts of values and how these might be overcome by accounting for parity and essential incompleteness. It is also shown that one intuitively compelling notion of disagreement does not give rise to a proper distance measure. (shrink)

According to the fitting-attitude analysis of value , to be valuable is to be a fitting object of a pro-attitude. In earlier publications, setting off from this format of analysis, I proposed a modelling of value relations which makes room for incommensurability in value. In this paper, I first recapitulate the value modelling and then move on to suggest adopting a structurally similar analysis of probability. Indeed, many probability theorists from Poisson onwards did adopt an analysis of this kind. This (...) move allows to formally model probability and probability relations in essentially the same way as value and value relations. One of the advantages of the model is that we get a new account of Keynesian incommensurable probabilities, which goes beyond Keynes in distinguishing between different types of incommensurability. It also becomes possible to draw a clear distinction between incommensurability and vagueness in probability comparisons. (shrink)

This paper presents a formal characterization of a two stage decision rule. This characterization involves three conditions which, together, are satisfied by any choice function that can be represented as a two-tier choice function. And any choice function satisfying these three conditions can be represented as a two-tier choice function. The first condition identifies particular features of two-tier choice functions when they violate Property α. The other two conditions are essentially existence claims, required to ensure that the two tiers of (...) a choice function can be represented as (pseudo-) rationalizable choice functions. My aim is to offer a formal result that provides insight into the nature of two-tier decisions. The more we understand how a particular decision procedure operates, the more we should expect to predict its results accurately, and the more we should be able to understand the circumstances under which its use is (and is not) appropriate. (shrink)

What does it mean to be irresponsible in developing or using a technology? There are two fundamentally different answers to this question and they each generate research strands that differ in scope, style and applicability. To capture this difference, I make use of two mythical creatures of Jewish origin that have been employed in the past to represent relationships between man and man-made entities: the Golem (Collins and Pinch, 2002, 2005 ) and the Leviathan (Hobbes, 1994 ). The Golem is (...) the traditional image of technology as a creature that can be helpful but needs to be controlled. Irresponsibility in this perspective is the failure to exercise control. The Leviathan is the image of technology as a difficult compromise between fundamental values. Irresponsibility is in this perspective is allowing some values to systematically dominate others. Having worked out the basics of these images, I show that each comes with its specific methodological challenges: where the Golem gives rise to the Collingridge Dilemma of control, the Leviathan gives rise to Münchhausen’s trilemma of justification. Since the Golem image is predominant in scholarship on irresponsibility, I conclude with an appeal for a more equal distribution of efforts in conceptualizing technologies as Golems and as Leviathans. (shrink)

Suppose it is possible to make approximate interpersonal comparisons of welfare gains and losses. Thus, if w\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$w$$\end{document}, x\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$x$$\end{document}, y\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$y$$\end{document} and z\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$z$$\end{document} are personal states, then it is sometimes possible to say “The welfare gain of the state change w⇝x\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} (...) \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$w\leadsto x$$\end{document} is greater than the welfare gain of the state change y⇝z\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$y\leadsto z$$\end{document}”. We can represent this by the formula “⪰\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\succeq $$\end{document}”, where \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$$$\end{document} is a difference preorder: an incomplete preorder on the space of all possible personal state changes. A social state change is a bundle of personal state changes. A social difference preorder is an incomplete preorder on the space of social state changes, which satisfies Pareto and Anonymity axioms. We characterize a family of SDPs which are roughly utilitarian in nature. We also apply the model to redistributive taxation. (shrink)

It seems natural to choose whether to have a child by reflecting on what it would be like to actually have a child. I argue that this natural approach fails. If you choose to become a parent, and your choice is based on projections about what you think it would be like for you to have a child, your choice is not rational. If you choose to remain childless, and your choice is based upon projections about what you think it (...) would be like for you to have a child, your choice is not rational. This suggests we should reject our ordinary conception of how to make this life-changing decision, and raises general questions about how to rationally approach important life choices. (shrink)

We describe a logic of preference in which modal connectives reflect reasons to desire that a sentence be true. Various conditions on models are introduced and analyzed.

So-called ‘existential risks’ present virtually unlimited reasons for probing them and responses to them further. The ensuing normative pull to respond to such risks thus seems to present us with r...

In this paper we explore the connections between ethics and decision theory. In particular, we consider the question of whether decision theory carries with it a bias towards consequentialist ethical theories. We argue that there are plausible versions of the other ethical theories that can be accommodated by “standard” decision theory, but there are also variations of these ethical theories that are less easily accommodated. So while “standard” decision theory is not exclusively consequentialist, it is not necessarily ethically neutral. Moreover, (...) even if our decision-theoretic models get the right answers vis-`a-vis morally correct action, the question remains as to whether the motivation for the non-consequentialist theories and the psychological processes of the agents who subscribe to those ethical theories are lost or poorly represented in the resulting models. (shrink)

The aim of this paper is to provide a detailed characterisation of some ways in which our preferences reflect our reasons. I will argue that practical reasons can be characterised along two dimensions that influence our preferences: their balance and their weight. This is analogous to a similar characterisation of the way in which probabilities reflect the balance and weight of evidence in epistemology. In this paper, I will illustrate the distinction between the balance and weight of reasons, and show (...) how this is crucial for an adequate account of preference and choice. The upshot is a more complete picture of a particular kind of decision, labelled by Isaac Levi and, more recently, Ruth Chang as ‘hard choices’. These are choices in which one option is better than another in some ways, the other is better than the first in some ways, but neither seems better overall. The distinction between the balance and weight of reasons presents a new way of understanding how hard choices vary by degree and what it is that makes them so hard. (shrink)

We live in a world which is more connected than ever before. We can now send messages to a friend or colleague with a touch of a button, can learn about other’s interests before we even meet them, and now leave a digital trail behind us—whether we intend to or not. One question which, in proportion to its importance, has been asked quite infrequently since the dawn of the Internet era involves exactly how meaningful all of these connections are. To (...) what extent can we love another if we only communicate via social technology? What value does visiting a friend have which e-mailing him or texting him does not? “Social Media, Love, and the Look of the Other” attempts to answer these questions by applying the framework of social communication established by Jean-Paul Sartre to the realm of social media. Sartre writes that in all communications with the other, we face the look of the other—or our own perception of how the other judges us. The direction in which the look points determines, to a large degree, the character of any interaction with others. How does social media affect the nature of this look? Particularly, this inquiry seeks to discover the nature of the object to which this look points—and what implications, in cases where the look is not directed at ourselves, this has on our ability to develop and share concern for others. (shrink)

The idea that rational agents should have acyclic preferences and should obey conditionalization has been defended on the grounds that otherwise an agent is threatened with becoming a “money pump.” This essay argues that such arguments fail to prove their claims.

The idea that rational agents should have acyclic preferences and should obey conditionalization has been defended on the grounds that otherwise an agent is threatened with becoming a “money pump.” This essay argues that such arguments fail to prove their claims.

This is a brief review of issues over which Henry Kyburg and I differed concerning the requirement that full beliefs should be closed under deductive consequence.

One can interpret the No Probabilities for Acts-Principle, namely that any adequate quantitative decision model must in no way contain subjective probabilities for actions in two ways: it can either refer to actions that are performable now and extend into the future or it can refer to actions that are not performable now, but will be in the future. In this paper, I will show that the former is the better interpretation of the principle.

In this study, we analyze choice in the presence of some conflict that affects the decision time, a subject that has been documented in the literature. We axiomatize a multiattribute decision time representation, which is a dynamic extension of the classic multiattribute expected utility theory that allows potentially incomplete preferences. Under this framework, one alternative is preferred to another in a certain period if and only if the weighted sum of the attribute-dependent expected utility induced by the former alternative is (...) larger than that induced by the latter for all attribute weights in a closed and convex set. MDT uniquely determines the decision time as the earliest period at which the ranking between alternatives becomes decisive. The comparative statics result indicates that the decision time provides useful information to locate indifference curves in a specific setting. MDT also explains various empirical findings in economics and other relevant fields. (shrink)

It is commonplace to suppose that the theory of individual rational choice is considerably less problematic than the theory of collective rational choice. In particular, it is often assumed by philosophers, economists, and other social scientists that an individual's choices among outcomes accurately reflect that individual's underlying preferences or values. Further, it is now well known that if an individual's choices among outcomes satisfy certain plausible axioms of rationality or consistency, that individual's choice-behavior can be interpreted as maximizing expected utility (...) on a utility scale that is unique up to a linear transformation. Hence, there is, in principle, an empirically respectable method of measuring individuals' values and a single unified schema for explaining their actions as value maximizing. (shrink)

An argument is advanced to show why E-admissibility should be preferred over maximality as a principle of rational choice where rationality is understood as minimal rationality. Consideration is given to the distinction between second best and second worst options in three way choice that is ignored according to maximality. It is shown why the behavior exhibited in addressing the problems posed by Allais (Econometrica 21:503–546, 1952) and by Ellsberg (Q Econ 75:643–669, 1961) do not violate the independence postulate according to (...) minimal rationality. (shrink)

This paper presents a proof of concept for a graphical models approach to assessing the moral coherence and moral robustness of systems of social interactions. “Moral coherence” refers to the degree to which the rights and duties of agents within a system are effectively respected when agents in the system comply with the rights and duties that are recognized as in force for the relevant context of interaction. “Moral robustness” refers to the degree to which a system of social interaction (...) is configured to ensure that the interests of agents are effectively respected even in the face of noncompliance. Using the case of conscientious objection of pharmacists to filling prescriptions for emergency contraception as an example, we illustrate how a graphical models approach can help stakeholders identify structural weaknesses in systems of social interaction and evaluate the relative merits of alternate organizational structures. By illustrating the merits of a graphical models approach we hope to spur further developments in this area. (shrink)

Set-valued choice functions provide a framework that is general enough to encompass a wide variety of theories that are significant to the study of rationality but, at the same time, offer enough structure to articulate consistency conditions that can be used to characterize some of the theories within this encompassed variety. Nonetheless, two-tiered choice functions, such as those advocated by Isaac Levi, are not easily characterized within the framework of set-valued choice functions. The present work proposes conditional choice functions as (...) the proper carriers of synchronic rationality. The resulting framework generalizes the familiar one mentioned above without emptying it and, moreover, provides a natural setting for two-tiered choice rules. (shrink)

Two types of measures of probabilistic uncertainty are introduced and investigated. Dispersion measures report how diffused the agent’s second-order probability distribution is over the range of first-order probabilities. Robustness measures reflect the extent to which the agent’s assessment of the prior (objective) probability of an event is perturbed by information about whether or not the event actually took place. The properties of both types of measures are investigated. The most obvious type of robustness measure is shown to coincide with one (...) of the major candidates for a dispersion measure, the mean square deviation measure. (shrink)

Although it has often been claimed that all the information contained in second-order probabilities can be contained in first-order probabilities, no practical recipe for the elimination of second-order probabilities without loss of information seems to have been presented. Here, such an elimination method is introduced for repeatable events. However, its application comes at the price of losses in cognitive realism. In spite of their technical eliminability, second-order probabilities are useful because they can provide models of important features of the world (...) that are cognitively more plausible than those that can be obtained with single-level probabilities. (shrink)