Paul Weirich

Classical bargaining theory attempts to solve a bargaining problem using only the information about the problem contained in the representation of its possible outcomes in utility space. However, this information usually underdetermines the solution. I use additional information about interpersonal comparisons of utility and bargaining power. The solution is then the outcome that maximizes the sum of power-weighted utilities. I use these results to advance a contractarian argument for a utilitarian form of social cooperation. As the original position, I propose a hypothetical situation in which the members of society are rational, fully informed, free, and equal. I argue that in this original position they would adopt a utilitarian form of social cooperation. I conclude that utilitarian cooperation constitutes a moral ideal toward which society ought to aspire.

Food products with genetically modified (GM) ingredients are common, yet many consumers are unaware of this. When polled, consumers say that they want to know whether their food contains GM ingredients, just as many want to know whether their food is natural or organic. Informing consumers is a major motivation for labeling. But labeling need not be mandatory. Consumers who want GM-free products will pay a premium to support voluntary labeling. Why do consumers want to know about GM ingredients? GM foods are tested to ensure safety and have been on the market for more than a decade. Still, many consumers, including some with food allergies, want to be cautious. Also, GM crops may affect neighboring plants through pollen drift. Despite tests for environmental impact, some consumers may worry that GM crops will adversely effect the environment. The study of risk and its management raises questions not settled by the life sciences alone. This book surveys various labeling policies and the cases for them. It is the first comprehensive, interdisciplinary treatment of the debate about labeling genetically modified food. The contributors include philosophers, bioethicists, food and agricultural scientists, attorneys/legal scholars, and economists.

I will characterize the utilitarian and maximin rules of social choice game-theoretically. That is, I will introduce games whose solutions are the utilitarian and maximin distributions respectively. Then I will compare the rules by exploring similarities and differences between these games. This method of comparison has been carried out by others. But I characterize the two rules using games that involve bargaining within power structures. This new characterization better highlights the ethical differences between the rules.

When new technologies create risks, government agencies use regulations to control the risks. This paper advances a method of evaluating a democracy’s regulation of risks. It assumes that a regulatory agency should act as the public would act in ideal conditions for negotiation if the public were rational and informed. The method relies on decision theory and game theory to ascertain whether a regulation has the public’s informed support. The Occupational Safety and Health Administration’s regulation of exposure to carcinogens in the workplace illustrates the account of regulation. The illustration draws attention to a distinction between physical and information-sensitive risks. Regulations guided by the physical sciences alone may overlook the value of reducing information-sensitive risks. These risks exist objectively, and rational people generally have an aversion to them. An information-sensitive risk and an aversion to it may persist after acquisition of all available relevant information. Democratic regulation justifiably aims to reduce such risks.

This book represents a major contribution to game theory. It offers this conception of equilibrium in games: strategic equilibrium. This conception arises from a study of expected utility decision principles, which must be revised to take account of the evidence a choice provides concerning its outcome. The argument for these principles distinguishes reasons for action from incentives, and draws on contemporary analyses of counterfactual conditionals. The book also includes a procedure for identifying strategic equilibria in ideal normal-form games. In synthesizing decision theory and game theory in a powerful way this book will be of particular interest to all philosophers concerned with decision theory and game theory as well as economists and other social scientists.

Collective rationality in its ordinary sense is rationality’s extension to groups. It does not entail efficiency by definition. Showing that it entails efficiency requires a normative argument. Game theorists treating cooperative games generally assume that collective rationality entails efficiency, but formulating the reasoning that leads individuals to efficiency, and verifying the rationality of its steps, presents challenging philosophical issues. This paper constructs a framework for addressing those issues and reaches some preliminary results about the prospects of rational agents achieving efficiency in coalitional games. It concludes that only under strong idealizations does collective rationality entail efficiency

Agents face serious obstacles to making optimal decisions. For instance, their cognitive limits stand in the way. John Pollock’s book, Thinking about Acting , suggests many ways of revising decision principles to accommodate human limits and to direct limited, artificial agents. The book’s main proposal is to replace optimization, or expected-utility maximization, with locally global planning. This essay describes optimization and locally global planning, and then argues that optimization among salient options has the virtues of locally global planning without certain drawbacks. Although it does not endorse locally global planning, it recommends that decision theory incorporate some of the book’s ideas about settling for improvements when optimization among all options is unrealistic.

This paper summarizes and rebuts the three standard objections made by social choice theorists against interpersonal utility. The first objection argues that interpersonal utility is measningless. I show that this objection either focuses on irrelevant kinds of meaning or else uses implausible criteria of meaningfulness. The second objection argues that interpersonal utility has no role to play in social choice theory. I show that on the contrary interpersonal utility is useful in formulating goals for social choice. The third objection argues that interpersonal utility in social choice theory can be replaced by clearer notions. I show that the replacements proposed are unsatisfactory in either interpersonal utility's descriptive or explanatory role. My conclusion is that interpersonal utility has a legitimate place in social choice theory.

To handle epistemic and pragmatic risks, Gärdenfors and Sahlin (1982, 1988) design a decision procedure for cases in which probabilities are indeterminate. Their procedure steps outside the traditional expected utility framework. Must it do this? Can the traditional framework handle risk? This paper argues that it can. The key is a comprehensive interpretation of an option's possible outcomes. Taking possible outcomes more broadly than Gärdenfors and Sahlin do, expected utility can give risk its due. In particular, Good's (1952) decision procedure adequately handles indeterminate probabilities and the risks they generate.

The conditional probability of h given e is commonly claimed to be equal to the probability that h would have if e were learned. Here I contend that this general claim about conditional probabilities is false. I present a counter-example that involves probabilities of probabilities, a second that involves probabilities of possible future actions, and a third that involves probabilities of indicative conditionals. In addition, I briefly defend these counter-examples against charges that the probabilities they involve are illegitimate

How do rational agents coordinate in a single-stage, noncooperative game? Common knowledge of the payoff matrix and of each player's utility maximization among his strategies does not suffice. This paper argues that utility maximization among intentions and then acts generates coordination yielding a payoff-dominant Nash equilibrium. ‡I thank the audience at my paper's presentation at the 2006 PSA meeting for many insightful points. †To contact the author, please write to: Philosophy Department, University of Missouri, Columbia, MO 65211; e-mail: [email protected].

Standard principles of rational decision assume that an option's utility is both comprehensive and accessible. These features constrain interpretations of an option's utility. This essay presents a way of understanding utility and laws of utility. It explains the relation between an option's utility and its outcome's utility and argues that an option's utility is relative to a specification of the option. Utility's relativity explains how a decision problem's framing affects an option's utility and its rationality even for an agent who is cognitively perfect and lacks only empirical information. The essay rewrites standard laws of utility to accommodate relativization to propositions' specifications. The new laws are generalizations of the standard laws and yield them as special cases.