Cooperation is the foundation of human social life, but it sometimes requires individuals to choose against their individual self-interest. How then is cooperation sustained? How do we decide when instead to follow our own goals? I develop a model that builds on Bacharach (in: Gold, Sugden (eds) Beyond individual choice: teams and frames in game theory, 2006) ‘circumspect we-reasoning’ to address these questions. The model produces a threshold cost/benefit ratio to describe when we-reasoning players should choose cooperatively. After assumptions regarding (...) player types and beliefs, we predict how the extent of cooperation varies across games. Results from two experiments offer strong support to the models and predictions herein. (shrink)

In a seminal paper, Aumann (1987, Econometrica 55, 1–18) showed how the choices of rational players could be analyzed in a unified state space framework. His innovation was to include the choices of the players in the description of the states, thus abolishing Savage’s (1954, The Foundations of Statistics. Wiley, New York) distinction between acts and consequences. But this simplification comes at a price: Aumann’s notion of Bayes rationality does not allow players to evaluate what would happen were they to (...) deviate from their actual choices. We show how the addition of a causal structure to the framework enables us to analyze such counterfactual statements, and use it to introduce a notion of causal rationality. Under a plausible causal independence condition, the two notions are shown to be equivalent. If we are prepared to accept this condition we can dispense with the causal apparatus and retain Aumann’s original framework. (shrink)

(2001). Collective reasoning: A critique of Martin Hollis's position. Critical Review of International Social and Political Philosophy: Vol. 4, Trusting in Reason: Martin Hollis and the Philosophy of Social Action, pp. 171-192.

Challenging, with several powerful arguments, some of our deepest beliefs about rationality, morality, and personal identity, Parfit claims that we have a false view about our own nature. It is often rational to act against our own best interersts, he argues, and most of us have moral views that are self-defeating. We often act wrongly, although we know there will be no one with serious grounds for complaint, and when we consider future generations it is very hard to avoid conclusions (...) that most of us will find very disturbing. (shrink)

The chapter reviews recent theoretical and empirical developments concerning the theory of team reasoning in game theoretic interactions.

This is the classic work upon which modern-day game theory is based. What began as a modest proposal that a mathematician and an economist write a short paper together blossomed, when Princeton University Press published Theory of Games and Economic Behavior. In it, John von Neumann and Oskar Morgenstern conceived a groundbreaking mathematical theory of economic and social organization, based on a theory of games of strategy. Not only would this revolutionize economics, but the entirely new field of scientific inquiry (...) it yielded--game theory--has since been widely used to analyze a host of real-world phenomena from arms races to optimal policy choices of presidential candidates, from vaccination policy to major league baseball salary negotiations. And it is today established throughout both the social sciences and a wide range of other sciences. (shrink)

The literature of economic theory, like that of philosophy, abounds in prefaces and prolegomena. Methodology and analysis of concepts take an important place in a science which has not found the sure path of development. But there is no sure path for methodology either. The selfconscious methodology of social science has been largely a borrowing from that of physical science, where procedures have developed to a stage of considerable maturity. But the analogy falls down where guidance is most needed, at (...) the points where social science is most likely to develop new concepts and new types of structure. Philosophers have not been lacking, indeed, to belittle the entire enterprise, and to deny the possibility of anything that could strictly be called social science. (shrink)

When my family discusses how we should spend a summer holiday, we start from certain common understandings about our preferences. We prefer self-catering accommodation to hotels, and hotels to campsites. We prefer walking and looking at scenery and wildlife to big-city sightseeing and shopping. When it comes to walks, we prefer walks of six miles or so to ones which are much shorter or much longer, and prefer well-marked but uncrowded paths to ones which are either more rugged or more (...) popular. And so on. These common understandings greatly simplify the task of choosing between holiday destinations and activities, by allowing us quickly to eliminate many options. But what does it mean to say that we prefer one thing to another? (shrink)

This paper proposes a concept of intentional cooperation for mutual benefit. This concept uses a form of team reasoning in which team members aim to achieve common interests, rather than maximising a common utility function, and in which team reasoners can coordinate their behaviour by following pre-existing practices. I argue that a market transaction can express intentions for mutually beneficial cooperation even if, extensionally, participation in the transaction promotes each party’s self-interest.

Abstract Orthodox decision theory presupposes that agency is invested in individuals. An opposing literature allows team agency to be invested in teams whose members use distinctive modes of team reasoning. This paper offers a new conceptual framework, inspired by David Lewis's analysis of common reasons for belief, within which team reasoning can be represented. It shows how individuals can independently endorse a principle of team reasoning which prescribes acting as a team member conditional on assurance that others have endorsed the (...) same principle. It argues that there can be such assurance even when no individual has an obligation to act on team reasoning. *This paper originated in a lecture that I gave at a Colloquium on Collective Intentions at Erasmus University Rotterdam. I thank participants, and particularly Govert den Hartogh, for comments. The analysis presented in this paper is an offshoot of a larger project, which uses David Lewis's work as the starting point for a reconstruction of the foundations of game theory. That project is joint work with Robin Cubitt. The specific idea of using this approach to analyse team reasoning grew out of a discussion with Michael Bratman. My work was supported by the Leverhulme Trust. (shrink)

For most of the problems that economists consider, the assumption that agents are self-interested works well enough, generating predictions that are broadly consistent with observation. In some significant cases, however, we find economic behavior that seems to be inconsistent with self-interest. In particular, we find that some public goods and some charitable ventures are financed by the independent voluntary contributions of many thousands of individuals. In Britain, for example, the lifeboat service is entirely financed by voluntary contributions. In all rich (...) countries, charitable appeals raise large amounts of money for famine relief in the Third World. The willingness of individuals to contribute to such projects is an economic fact that requires an explanation. (shrink)

For most of the problems that economists consider, the assumption that agents are self-interested works well enough, generating predictions that are broadly consistent with observation. In some significant cases, however, we find economic behavior that seems to be inconsistent with self-interest. In particular, we find that some public goods and some charitable ventures are financed by the independent voluntary contributions of many thousands of individuals. In Britain, for example, the lifeboat service is entirely financed by voluntary contributions. In all rich (...) countries, charitable appeals raise large amounts of money for famine relief in the Third World. The willingness of individuals to contribute to such projects is an economic fact that requires an explanation. (shrink)

The author identifies and defines the features of traditional utilitarian theories which account for their appeal, demonstrates that no theory which is "exclusively act-oriented" can have all the properties that ultilitarians have attempted to build into their theories, and develops a new theory "co-operative utilitarianism", which is radically different than traditional theories.

_ Convention_ was immediately recognized as a major contribution to the subject and its significance has remained undiminished since its first publication in 1969. Lewis analyzes social conventions as regularities in the resolution of recurring coordination problems-situations characterized by interdependent decision processes in which common interests are at stake. Conventions are contrasted with other kinds of regularity, and conventions governing systems of communication are given special attention.

We argue that a Bayesian explanation of strategic choices in games requires introducing a psychological theory of belief formation. We highlight that beliefs in epistemic game theory are derived from the actual choice of the players, and cannot therefore explain why Bayesian rational players should play the strategy they actually chose. We introduce the players’ capacity of mindreading in a game theoretical framework with the simulation theory, and characterise the beliefs that Bayes rational players could endogenously form in games. We (...) show in particular that those beliefs need not be ratifiable, and therefore that rational players can form action-dependent beliefs. (shrink)

The game theoretic notion of best-response reasoning is sometimes criticized when its application produces multiple solutions of games, some of which seem less compelling than others. The recent development of the theory of team reasoning addresses this by suggesting that interacting players in games may sometimes reason as members of a team – a group of individuals who act together in the attainment of some common goal. A number of properties have been suggested for team-reasoning decision-makers’ goals to satisfy, but (...) a few formal representations have been discussed. In this paper we suggest a possible representation of these goals based on the notion of mutual advantage. We propose a method for measuring extents of individual and mutual advantage to the interacting decision-makers, and define team interests as the attainment of outcomes associated with maximum mutual advantage in the games they play. (shrink)

This book defends the view that any adequate account of rational decision making must take a decision maker's beliefs about causal relations into account. The early chapters of the book introduce the non-specialist to the rudiments of expected utility theory. The major technical advance offered by the book is a 'representation theorem' that shows that both causal decision theory and its main rival, Richard Jeffrey's logic of decision, are both instances of a more general conditional decision theory. The book solves (...) a long-standing problem for Jeffrey's theory by showing for the first time how to obtain a unique utility and probability representation for preferences and judgements of comparative likelihood. The book also contains a major new discussion of what it means to suppose that some event occurs or that some proposition is true. The most complete and robust defence of causal decision theory available. (shrink)

This book makes a significant contribution to the standard decision theory, that is, the theory of choice built around the principle of maximizing expected utility, both to its causal version and to the more traditional noncausal approach. The author’s success in clarifying the foundations of the standard decision theory in general, and causal decision theory in particular, also makes the book uniquely suitable for a person whose research in philosophy has led her to want to learn about contemporary decision theory. (...) The book presupposes some mathematical sophistication, and it contains more philosophical and mathematical argumentation per page than may be suitable for an undergraduate level course; but it stands out as an ideal textbook for a graduate-level course focused on the foundations of the standard decision theory. (shrink)

Focal points seem to be important in helping players coordinate their strategies in coordination problems. Game theory lacks, however, a formal theory of focal points. This paper proposes a theory of focal points that is based on individual rationality considerations. The two principles upon which the theory rest are the Principle of Insufficient Reason (IR) and a Principle of Individual Team Member Rationality. The way IR is modelled combines the classic notion of description symmetry and a new notion of pay-off (...) symmetry, which yields different predictions in a variety of games. The theory can explain why people do better than pure randomization in matching games. (shrink)

In the literature of collective intentions, the ‘we-intentions’ that lie behind cooperative actions are analysed in terms of individual mental states. The core forms of these analyses imply that all Nash equilibrium behaviour is the result of collective intentions, even though not all Nash equilibria are cooperative actions. Unsatisfactorily, the latter cases have to be excluded either by stipulation or by the addition of further, problematic conditions. We contend that the cooperative aspect of collective intentions is not a property of (...) the intentions themselves, but of the mode of reasoning by which they are formed. We analyse collective intentions as the outcome of team reasoning, a mode of practical reasoning used by individuals as members of groups. We describe this mode of reasoning in terms of formal schemata, discuss a range of possible accounts of group agency, and show how existing theories of collective intentions fit into this framework. (shrink)

A number of authors, Including Thomas Schelling and David Lewis, have envisaged a model of the generation of action in coordination problems in which salience plays a crucial role. Empirical studies suggest that human subjects are likely to try for the salient combination of actions, a tendency leading to fortunate results. Does rationality dictate that one aim at the salient combination? Some have thought so, Thus proclaiming that salience is all that is needed to resolve coordination problems for agents who (...) are rational in the sense of game theory. I argue against this position; rational agents will not necessarily aim for the salient. It remains to explain how the salient comes to be chosen by human beings. Various possibilities are noted. One involves a mechanism invoked by Hume and Wittgenstein in other contexts: we may project an unreasoned compulsion onto reason, falsely believing that rationality dictates our choice of the salient. (shrink)

Is morality rational? In this book Gauthier argues that moral principles are principles of rational choice. He proposes a principle whereby choice is made on an agreed basis of cooperation, rather than according to what would give an individual the greatest expectation of value. He shows that such a principle not only ensures mutual benefit and fairness, thus satisfying the standards of morality, but also that each person may actually expect greater utility by adhering to morality, even though the choice (...) did not have that end primarily in view. In resolving what may appear to be a paradox, the author establishes morals on the firm foundation of reason. Gauthier's argument includes an account of value, linking it to preference and utility; a discussion of the curcumstances in which morality is unnecessary; and an application of morals by agreement to relations between peoples at different levels of development and different generations. Finally, he reflects on the assumptions about individuality and community made by his account of rationality and morality. (shrink)

Over the past two decades, academic economics has undergone a mild revolution in methodology. The language, concepts and techniques of noncooperative game theory have become central to the discipline. This book provides the reader with some basic concepts from noncooperative theory, and then goes on to explore the strengths, weaknesses, and future of the theory as a tool of economic modelling and analysis. The central theses are that noncooperative game theory has been a remarkably popular tool in economics over the (...) past decade because it allows analysts to capture essential features of dynamic competition and competition where some parties have proprietary information. The theory is weakest in providing a sense of when it - and equilibrium analysis in particular - can be applied and what to do when equilibrium analysis is inappropriate. Many of these weaknesses can be addressed by the consideration of individuals who are boundedly rational and learn imperfectly from the past. Written in a non-technical style and working by analogy, the book, first given as part of the Clarendon Lectures in Economics, is readily accessible to a broad audience and will be of interest to economists and students alike. Knowledge of game theory is not required as the concepts are developed as the book progresses. (shrink)

The question Jon Elster addresses in this challenging book is what binds societies together and prevents them from disintegrating into chaos and war. He analyses two concepts of social order: stable, predictable patterns of behaviour, and co-operative behaviour. The book examines various aspects of collective action and bargaining from the perspective of rational-choice theory and the theory of social norms. It is a fundamental assumption of the book that social norms provide an important kind of motivation for action that is (...) irreducible to rationality. The book represents a major statement by Elster, which will be of particular interest to political scientists, political philosophers, sociologists, and economists. (shrink)

This is a revision of game theory which takes account of agents' own descriptions of their situations, and which allows people to reason as members of groups.

The 'Evolution of Cooperation' addresses a simple yet age-old question; If living things evolve through competition, how can cooperation ever emerge? Despite the abundant evidence of cooperation all around us, there existed no purely naturalistic answer to this question until 1979, when Robert Axelrod famously ran a computer tournament featuring a standard game-theory exercise called The Prisoner's Dilemma. To everyone's surprise, the program that won the tournament, named Tit for Tat, was not only the simplest but the most "cooperative" entrant. (...) This unexpected victory proved that cooperation - one might even say altruism - is mathematically possible and therefore needs no hidden hand or divine agent to create and sustain it. A great roadblock to the understanding of all sorts of behavior was at last removed. The updated edition includes an extensive new chapter on cooperation in cancer cells and among terrorist organizations. (shrink)

Analyzes the nature of international disagreements and conflict resolution in terms of game theory and non-zero-sum games.

Decision theory explains weakness of will as the result of a conflict of incentives between different transient agents. In this framework, self-control can only be achieved by the I-now altering the incentives or choice-sets of future selves. There is no role for an extended agency over time. However, it is possible to extend game theory to allow multiple levels of agency. At the inter-personal level, theories of team reasoning allow teams to be agents, as well as individuals. I apply team (...) reasoning at the intra-personal level, taking the self as a team of transient agents over time. This allows agents to ask, not just “what should I-now do?’, but also ‘What should I, the person over time do?’, which may enable agents to achieve self-control. The resulting account is Aristotelian in flavour, as it involves reasoning schemata and perception, and it is compatible with some of the psychological findings about self-control. (shrink)

Originally published in 1941, this book contains the French text of Jean-Jacques Rousseau's 1755 treatise Discours sur l'origine et les fondements de l'inégalité parmi les hommes, in which he examines the artificial origins of human social structures designed to keep one group elevated above another. The preface by F. C. Green provides the historical context for Rousseau's essay and explains its influence on the authors of the French Revolution. This book will be of value to anyone with an interest in (...) French history or political philosophy. (shrink)

We explore the idea that a group or ‘team’ of individuals can be an agent in its own right and that, when this is the case, individual team members use team reasoning, a distinctive mode of reasoning from that of standard decision theory. Our approach is to represent team reasoning explicitly, by means of schemata of practical reasoning in which conclusions about what actions should be taken are inferred from premises about the decision environment and about what agents are seeking (...) to achieve. We use this theoretical framework to compare team reasoning with the individual reasoning of standard decision theory, and to compare various theories of team agency and collective intentionality. (shrink)