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)

Using as examples Akerlof's 'market for ''lemons''' and Schelling's 'checkerboard' model of racial segregation, this paper asks how economists' abstract theoretical models can explain features of the real world. It argues that such models are not abstractions from, or simplifications of, the real world. They describe counterfactual worlds which the modeller has constructed. The gap between model world and real world can be filled only by inductive inference, and we can have more confidence in such inferences, the more credible the (...) model is as an account of what could have been true. (shrink)

This paper asks how, in science in general and in economics in particular, theoretical models aid the understanding of real-world phenomena. Using specific models in economics and biology as test cases, it considers three alternative answers: that models are tools for isolating the ‘capacities’ of causal factors in the real world; that modelling is ‘conceptual exploration’ which ultimately contributes to the development of genuinely explanatory theories; and that models are credible counterfactual worlds from which inductive inferences can be made. The (...) paper argues that the ‘credible worlds’ account captures significant aspects of scientific practice, even if many modellers see their work as conceptual exploration. (shrink)

Neoclassical economics assumes that individuals have stable and context-independent preferences, and uses preference satisfaction as a normative criterion. By calling this assumption into question, behavioural findings cause fundamental problems for normative economics. A common response to these problems is to treat deviations from conventional rational choice theory as mistakes, and to try to reconstruct the preferences that individuals would have acted on, had they reasoned correctly. We argue that this preference purification approach implicitly uses a dualistic model of the human (...) being, in which an inner rational agent is trapped in an outer psychological shell. This model is psychologically and philosophically problematic. (shrink)

The authors explore the history of experiments in economics, provide examples of different types of experiments and show that the growing use of experimental methods is transforming economics into an empirical science.

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)

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)

David Lewis is widely credited with the first formulation of common knowledge and the first rigorous analysis of convention. However, common knowledge and convention entered mainstream game theory only when they were formulated, later and independently, by other theorists. As a result, some of the most distinctive and valuable features of Lewis' game theory have been overlooked. We re-examine this theory by reconstructing key parts in a more formal way, extending it, and showing how it differs from more recent game (...) theory. In contrast to current theories of common knowledge, Lewis' theory is based on an explicit analysis of the modes of reasoning that are accessible to rational individuals and so can be used to analyse the genesis of common knowledge. Lewis' analysis of convention emphasises the role of inductive reasoning and of salience in the maintenance of conventions over time. Footnotes Earlier versions of this paper were presented at the 13th Amsterdam Colloquium at the University of Amsterdam, at a workshop on social norms at Wissenschaftskolleg zu Berlin, and at seminars at Tilburg University and the University of Bristol. We are grateful for comments from participants at those meetings, from two anonymous referees, and from Michael Bacharach, Nick Bardsley, Cristina Bicchieri, Luc Bovens, Simon Grant, David McCarthy, Shepley Orr, Brian Skyrms, Peter Vanderschraaf, Peter Wakker and Jörgen Weibull. Robert Sugden's work was supported by the Leverhulme Trust. (shrink)

John Broome has developed an account of rationality and reasoning which gives philosophical foundations for choice theory and the psychology of rational agents. We formalize his account into a model that differs from ordinary choice-theoretic models through focusing on psychology and the reasoning process. Within that model, we ask Broome’s central question of whether reasoning can make us more rational: whether it allows us to acquire transitive preferences, consistent beliefs, non-akratic intentions, and so on. We identify three structural types of (...) rationality requirements: consistency requirements, completeness requirements, and closedness requirements. Many standard rationality requirements fall under this typology. Based on three theorems, we argue that reasoning is successful in achieving closedness requirements, but not in achieving consistency or completeness requirements. We assess how far our negative results reveal gaps in Broome's theory, or deficiencies in choice theory and behavioral economics. (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 is an interview by the Erasmus Journal for Philosophy and Economics with Robert Sugden. The interview covers the intellectual trajectory of Sugden, from his early critique of Amartya Sen’s liberalism, to his interactions with James Buchanan and his contributions to behavioural economics. A major theme in the interview is Sugden’s development of a rival program of normative economics based on modern behavioural economics. The interview also discusses Sugden’s recent book The Community of Advantage which synthesizes many of the themes (...) he worked on. (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)

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.

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)

In this note, I comment on Julian Reiss's paper ?The explanation paradox?. I argue in support of two of the propositions that make up that paradox (that economic models are false, and that they are explanatory) but challenge the third proposition, that only true accounts can explain. I defend the ?credible worlds? account of models as fictions that are explanatory by virtue of similarity relations with real-world phenomena. I argue that Reiss's objections to the role of subjective similarity judgements in (...) explanation illegitimately presuppose the existence of rational criteria by which science can certify the objective validity of its explanation. (shrink)

I compare Mill's and Sen's accounts of the value of opportunity, focusing on a tension between two ideas they both uphold: that individual freedom is an important component of well-being, and that, because desires can be adaptive, actual desire is not always a good indicator of what will give well-being. The two writers' responses to this tension reflect different understandings of the relationship between freedom and desire. Sen links an individual's well-being to her freedom to choose what she has reason (...) to desire, and looks to a democratic political process for a collective judgement about what it is rational to desire. Mill links the individual's well-being to her freedom to act on her own desires, whatever they may be, within the constraints imposed by a fair initial distribution of resources. He sees no need for collective judgement about what is ultimately valuable in human life. I side with Mill. (Published Online February 16 2006). (shrink)

The paper explores how, in economics and biology, theoretical models are used as explanatory devices. It focuses on a modelling strategy by which, instead of starting with an unexplained regularity in the world, the modeller begins by creating a credible model world. The model world exhibits a regularity, induced by a mechanism in that world. The modeller concludes that there may be a part of the real world in which a similar regularity occurs and that, were that the case, the (...) model would offer an explanation. Little concrete guidance is given about where such a regularity might be found. Three modelling exercises in evolutionary game theory—one from economics and two from biology—are used as case studies. Two of these (one from each discipline) exemplify ‘explanation in search of observation’. The third goes a step further, analysing a regularity in a model world and treating it as informative about the real world, but without saying anything about real phenomena. The paper argues that if the relation between the model and real worlds is understood in terms of similarity, and if modelling is understood as an ongoing discovery process rather than as the demonstration of empirical truths, there can be value in creating explanations before finding the regularities that are to be explained. (shrink)

Game theory is central to modern understandings of how people deal with problems of coordination and cooperation. Yet, ironically, it cannot give a straightforward explanation of some of the simplest forms of human coordination and cooperation--most famously, that people can use the apparently arbitrary features of "focal points" to solve coordination problems, and that people sometimes cooperate in "prisoner's dilemmas." Addressing a wide readership of economists, sociologists, psychologists, and philosophers, Michael Bacharach here proposes a revision of game theory that resolves (...) these long-standing problems. In the classical tradition of game theory, Bacharach models human beings as rational actors, but he revises the standard definition of rationality to incorporate two major new ideas. He enlarges the model of a game so that it includes the ways agents describe to themselves their decision problems. And he allows the possibility that people reason as members of groups, each taking herself to have reason to perform her component of the combination of actions that best achieves the group's common goal. Bacharach shows that certain tendencies for individuals to engage in team reasoning are consistent with recent findings in social psychology and evolutionary biology. As the culmination of Bacharach's long-standing program of pathbreaking work on the foundations of game theory, this book has been eagerly awaited. Following Bacharach's premature death, Natalie Gold and Robert Sugden edited the unfinished work and added two substantial chapters that allow the book to be read as a coherent whole. (shrink)

This note replies to a comment by Daniel Hausman on our paper ‘Preference purification and the inner rational agent: a critique of the conventional wisdom of behavioural welfare economics’. We clarify our characterisation of behavioural welfare economics and acknowledge that Hausman does fully endorse this approach. However, we argue that Hausman’s response to our critique, like behavioural welfare economics itself, implicitly uses a model of an inner rational agent.

When modern economists use the notions of sympathy or empathy, they often claim that their ideas have their roots in Adam Smith's Theory of Moral Sentiments, while sometimes complaining that Smith fails to distinguish clearly enough between the two concepts. Recently, Philippe Fontaine has described various forms of sympathy and empathy, and has explored their respective roles in Smith's work. My objective in this paper is to argue that Smith's analysis of how people's sentiments impinge on one another involves a (...) concept of fellow-feeling that is distinct from both sympathy and empathy. Unlike sympathy and empathy, fellow-feeling does not fit into the ontological framework of rational choice theory – which may explain why it tends to be overlooked by modern readers of Smith. (shrink)

Research in psychology and behavioral economics shows that individuals’ choices often depend on “irrelevant” contextual factors. This presents problems for normative economics, which has traditionally used preference-satisfaction as its criterion. A common response is to claim that individuals have context-independent latent preferences which are “distorted” by psychological factors, and that latent preferences should be respected. This response implicitly uses a model of human action in which each human being has an “inner rational agent.” I argue that this model is psychologically (...) ungrounded. Although references to latent preferences appear in psychologically based explanations of context-dependent choice, latent preferences serve no explanatory purpose. (shrink)

This paper argues that measurements of opportunity which focus on the contents of a person's opportunity set fail to capture open-ended aspects of opportunity that liberals should value. I propose an alternative conception of which does not require the explicit specification of opportunity sets, and which rests on an understanding of persons as responsible rather than rational agents. I suggest that issues of distributive fairness are best framed in terms of real income, and that meaningful measurements of real income are (...) possible if opportunity as mutual advantage is ensured. (shrink)

Two roles of experiments in behavioural economics are distinguished ? experiments as exhibits and experiments as tests of theories. An exhibit is an experimental design which reliably induces a surprising regularity, typically combined with an informal hypothesis about the underlying causal mechanism. ?Deviation theories? ? generalisations of received theories which incorporate additional causal mechanisms ? are constructed so as to be consistent with known exhibits, and tested in new situations. The paper argues that the principles of good practice are different (...) for the two types of experiment, in part because of a tendency for successful exhibits to be produced by several causal mechanisms. (shrink)

An experiment is reported which tests for positive confirmation bias in a setting in which individuals choose what information to buy, prior to making a decision. The design – an adaptation of Wason's selection task – reveals the use that subjects make of information after buying it. Strong evidence of positive confirmation bias, in both information acquisition and information use, is found; and this bias is found to be robust to experience. It is suggested that the bias results from a (...) pattern of reasoning which, although producing sub-optimal decisions, is internally coherent and which is self-reinforcing. (shrink)

Ever since its first publication in 1970, Amartya Sen's paper “The Impossibility of a Paretian Liberal” has served as the starting point for almost all discussions of liberty in social choice theory. However, a number of people, myself included, have argued that Sen's theorem rests on a misleading characterization of liberty . In a recent paper, addressed to a philosophical audience, Sen has provided a careful defence of his theorem against this charge. I shall argue that this defence does not (...) work. (shrink)

The discovered preference hypothesis appears to insulate expected utility theory (EU) from disconfirming experimental evidence. It asserts that individuals have coherent underlying preferences, which experiments may not reveal unless subjects have adequate opportunities and incentives to discover which actions best satisfy their preferences. We identify the confounding effects to be expected in experiments, were that hypothesis true, and consider how they might be controlled for. We argue for a design in which each subject faces just one distinct choice task for (...) real. We review the results of some tests of EU which have used this design. These tests reveal the same violations of the independence axiom as other studies have found. We conclude that the discovered preference hypothesis does not justify scepticism about the reality of these effects. (shrink)

ABSTRACT This paper compares two alternative answers to the question ?Who is the addressee of welfare economics?? These answers correspond with different understandings of the status of the normative conclusions of welfare economics and have different implications for how welfare economics should be adapted in the light of the findings of behavioural economics. The conventional welfarist answer is that welfare economics is addressed to a ?social planner?, whose objective is to maximize the overall well-being of society; the planner is imagined (...) as a benevolent despot, receptive to the economist's advice. The alternative contractarian answer is that welfare economics is addressed to individuals who are seeking mutually beneficial agreements; a contractarian recommendation has the form ?It is in the interests of each of you separately that all of you together agree to do x?. Each of these answers should be understood as a literary convention that uses a highly simplified model of politics. I defend the contractarian approach and show that it is less supportive of ?soft paternalism? than is the welfarist approach. (shrink)

It is a truism that a market economy cannot function without trust. We must be able to rely on other people to respect our property rights, and on our trading partners to keep their promises. The theory of economics is incomplete unless it can explain why economic agents often trust one another, and why that trust is often repaid. There is a long history of work in economics and philosophy which tries to explain the kinds of reasoning that people use (...) when they engage in practices of trust: this work develops theoriesoftrust. A related tradition in economics, sociology and political science investigates the kinds of social institution that reproduce whatever habits, dispositions or modes of reasoning are involved in acts of trust: this work develops theoriesofsocialcapital. A recurring question in these literatures is whether a society which organizes its economic life through markets is capable of reproducing the trust on which those markets depend. In this paper, we look at these themes in relation to the writings of three eighteenth-century philosopher-economists: David Hume, Adam Smith, and Antonio Genovesi. (shrink)

Here a group of philosophers, economists and political theorists discuss the work of David Gauthier, which seeks to show that rational individuals would accept certain moral constraints on their choices. The possibilities and limitations of a contractarian approach to issues of justice is analyzed.

Hume is often read as proposing an instrumental theory of decision, in which an agent's choices are rational if they maximally satisfy her desires, given her beliefs. In fact, Hume denies that rationality can be attributed to actions. I argue that this is not a gap needing to be filled. Hume's theory provides a coherent and self-contained understanding of action, compatible with current developments in experimental psychology and behavioural economics. On Hume's account, desires are primitive psychological motivations which do not (...) have propositional content, and so are not subject to the criteria of rational consistency which apply to propositions. (shrink)

Until recently, economics was generally understood to be a nonexperimental science with a hypothetico‐deductive methodology. This article considers how the methodology of economics has changed with the spread of experimental methods. Initially, most experimental economists saw their work as testing pre‐existing theories. However, a method of systematic inductive enquiry in which theory plays a less central role is now evolving. This method is structured around the discovery and progressive refinement of regularities. “Exhibits”—experimental designs that generate significant regularities—are taking over some (...) of the functions formerly performed by theoretical models. †To contact the author, please write to: School of Economics, University of East Anglia, Norwich NR4 7TJ, UK; e‐mail: [email protected] (shrink)

We present an abstract model of rationality theories that focuses on structural properties of attitudes. We construe rationality as coherence between one's attitudes, e.g., one's beliefs, values, and intentions. We introduce three 'logical' conditions on attitudes: consistency, completeness, and closedness. They generalise the classic logical conditions on beliefs towards multiple attitudes, but contrast with standard rationality conditions such as transitivity for preferences, modus ponens for binary beliefs, additivity for probabilistic beliefs, and non-akrasia for intentions. We establish a formal correspondence between (...) our three logical conditions and standard rationality conditions. Addressing John Broome's enquiry into the achievability of rationality through reasoning, we characterize the extent to which explicit reasoning can help one become more 'logical', i.e., acquire consistent, complete, or closed attitudes, respectively. Our analysis forms a bridge between rationality and logic, and enables logical talk about multi-attitude psychology. (shrink)

In normative economic analysis, it is conventional to treat each person’s preferences as that person’s own standard of value, and as the standard by which the effects of public policies on that person should be valued. The proposal that preferences should be treated in this way is usually qualified by two apparently natural conditions—that preferences are internally coherent, and that they reflect the considered judgements of the person concerned. However, there is now a great deal of evidence suggesting that, in (...) many economic environments, preferences of the required kind simply do not exist. It seems that the preferences that govern people’s actual behaviour are often incoherent and unstable. This prompts the following question: Is there a defensible form of normative economics which respects each individual’s actual preferences, whatever form they take? I shall try to show that there is. (shrink)

First published in 2005, Economics and Social Interaction is a fresh attempt to overcome the traditional inability of economics to deal with interpersonal phenomena that occur within the sphere of markets and productive organizations. It makes use of traditional economic concepts for understanding interpersonal events, while venturing beyond those concepts to give a better account of personalised interactions. In contrast to other books, Economics and Social Interaction offers the reader a rigorous effort at extending economic analysis to a difficult field (...) in a consistent manner, sensitive to insights from other behavioural and social sciences. This collection represents an important contribution to a growing research agenda in the social sciences. (shrink)