Paul Weirich
Curators' Professor
Department of Philosophy
University of Missouri-Columbia
Columbia, MO 65211
Telephone: (573) 882-6760
Fax: (573) 884-8949

Curriculum Vitae (pdf)
I started studying decision theory while a graduate student at UCLA working under the supervision of Tyler Burge. When I finished my dissertation, Probability and Utility for Decision Theory, I published articles on a variety of topics but especially on the principle to maximize expected utility. My first book, Equilibrium and Rationality (Cambridge, 1998) generalizes that principle to cover the types of decisions arising in games of strategy. The result grounds a generalization of Nash equilibrium that I call strategic equilibrium. My second book, Decision Space (Cambridge, 2001) extends analysis of a decision’s utility by showing how the utility of fine-grained outcomes, possible worlds, depends on the logical consequences of satisfying basic intrinsic desires. My third book, Realistic Decision Theory (Oxford, 2004) generalizes the principle of expected utility maximization to cover cases in which agents have good excuses for failing to maximize expected utility. I am currently generalizing principles concerning rational pursuit of preferences so that they apply to collective agents, such as committees, as well as individual agents. Additionally, I have edited a volume, Labeling Genetically Modified Food (Oxford, 2007), based on a conference held here at the University of Missouri-Columbia.
Equilibrium and Rationality: Game Theory Revised by Decision Rules
Cambridge: Cambridge University Press, 1998
ISBN 0521593522

Equilibrium as John Nash conceived it is one of game theory’s most brilliant ideas. This book explains and generalizes Nash equilibrium. It dispenses with the usual restriction to finite games and introduces a general conception of strategic equilibrium. It uses the philosophical theory of counterfactual conditionals to achieve this generalization.

Here is the Cambridge website.
Decision Space: Multidimensional Utility Analysis
Cambridge: Cambridge University Press, 2001
ISBN 0521800099

Government regulatory agencies make complex decisions about public safety and health.  The Occupational Safety and Health Administration, for example, decides on standards for workplace exposure to benzene, a carcinogen.  To address such decisions, this book enriches utility theory.  It presents multiple ways of analyzing an option’s utility and unites them with a new, fundamental type of analysis using the intrinsic utility of meeting a basic goal.  The methods of utility analysis serve collective decisions as well as individual decisions.

Here is the Cambridge website.
Realistic Decision Theory: Rules for Nonideal Agents in Nonideal Circumstances
New York: Oxford University Press, 2004
ISBN 019517125X

Decision theory idealizes when formulating principles of rationality.  For example, take the principle to pick an option at the top of one’s preference ranking of options.  It presumes that one has a preference ranking of all options and knows that ranking.  Although idealizations are commonplace in a theory’s development, making the theory general requires removing its idealizations.  Removing them without losing precision is challenging but very rewarding.  It yields a realistic decision theory that covers cases in which agents have limited, imperfect resources and capacities for making decisions.  In particular, it covers agents who enter decision problems burdened with mistakes and explains when rationality requires correcting those mistakes.

Here is the Oxford website.
Labeling Genetically Modified Food: The Philosophical and Legal Debate
New York: Oxford University Press, 2007
ISBN13: 9780195326864
ISBN10: 0195326865

Many countries, such as countries in the European Union, require that food labels announce genetically modified ingredients. The United States does not require such labeling. Which labeling policy is best? This interdisciplinary book surveys various labeling policies and the cases for them. It is the first comprehensive treatment of the debate about labeling genetically modified food.

Here is the Oxford website.


Collective Rationality jacket

Collective Rationality: Equilibrium in Cooperative Games
Oxford University Press, 2010
ISBN 9780195388381

Collective rationality is just rationality applied to groups. A theory of collective rationality is part of a general theory of rationality. It formulates principles of rationality that govern collective acts. Principles of consistency and efficiency constrain ideal collective agents in ideal circumstances. In nonideal cases rationality recognizes excuses for inconsistency and inefficiency. A basic general principle of collective rationality judges that a group’s act is rational if rational acts of its members constitute the act.

In a cooperative game, individuals may act jointly and form coalitions. A solution to a cooperative game requires a profile of strategies, assigning exactly one strategy to each agent, such that each strategy in the profile is rational given the profile. A profile meeting this condition is an equilibrium. Principles of collective rationality characterize an equilibrium of a cooperative game. Identifying the equilibria of cooperative games aids the design of social institutions.

Here is the Oxford website.
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