Mark Blaug and I agree that if there is a realist interpretation of economic behavior to be discerned in Friedman, it is to be found not in Friedman's belief that the profit motive overrides other possible motives, but in his belief that a selection mechanism is working in competitive markets. Our joint sympathy for evolutionary economics is largely based on a conviction that the conception of competition as a dynamic evolutionary process is rather plausible. We disagree, however, on two issues: (...) first, how important the evolutionary conception was for Friedman's overall argument; and, second, whether we can learn something about the real world from rigorous formal analytical models. In this article, I explain and argue for my position on these two issues, and use Nelson and Winter's theory of evolutionary economics to support an illustrate my argument. (shrink)

This paper introduces and defends an account of model-based science that I dub model pluralism. I argue that despite a growing awareness in the philosophy of science literature of the multiplicity, diversity, and richness of models and modeling practices, more radical conclusions follow from this recognition than have previously been inferred. Going against the tendency within the literature to generalize from single models, I explicate and defend the following two core theses: any successful analysis of models must target sets of (...) models, their multiplicity of functions within science, and their scientific context and history and for almost any aspect x of phenomenon y, scientists require multiple models to achieve scientific goal z. (shrink)

Famously, Kripke has argued that the central portion of the Philosophical Investigations describes both a skeptical paradox and its skeptical solution. Solving the paradox involves the element of the community, which determines correctness conditions for rule-following behavior. What do such conditions precisely consist of? Is it accurate to say that there is no fact to the matter of rule following? How are the correctness conditions sustained in the community? My answers to these questions revolve around the idea that a rule (...) is followed insofar as a convention is in place. In particular, I consider the game-theoretic definition of convention offered by David Lewis and I show that it illuminates essential aspects of the communitarian understanding of rule-following. Make the following experiment: say “It’s cold here” and mean “It’s warm here”. Can you do it?Ludwig Wittgenstein, Philosophical Investigations, 1953, §510.I can’t say “it’s cold here” and mean “it’s warm here”—at least, not without a little help from my friends.David Lewis, Convention. (shrink)

We identify a social phenomenon in which large numbers of people seem to work towards a shared goal without explicitly trying to do so. We argue that this phenomenon – implicit coordination – is best understood as a form of joint agency differing from the forms most commonly discussed in the literature in the same way that individual actions driven by “explicit” intentions (those available for reflection and report) differ from individual actions driven by “implicit” intentions (those not thus available). (...) More precisely, implicit coordination is both analogous to wholly implicit individual intentions, and constituted by the partly implicit intentions of participants. We discuss the significance of this category for action theory, social ontology, and social criticism. (shrink)

In this article, I derive a weak version of Kant's categorical imperative within an informal game-theoretic framework. More specifically, I argue that Hobbesian agents would choose what I call the weak principle of universalization, if they had to decide on a rule of conflict resolution in an idealized but empirically defensible hypothetical decision situation. The discussion clarifies (i) the rationality requirements imposed on agents, (ii) the empirical conditions assumed to warrant the conclusion, and (iii) the political institutions that are necessary (...) to implement the derived principle. The analysis demonstrates the moral significance of the weak principle of universalization and its epistemic advantage over the categorical imperative. (shrink)

Like other mathematically intensive sciences, economics is becoming increasingly computerized. Despite the extent of the computation, however, there is very little true simulation. Simple computation is a form of theory articulation, whereas true simulation is analogous to an experimental procedure. Successful computation is faithful to an underlying mathematical model, whereas successful simulation directly mimics a process or a system. The computer is seen as a legitimate tool in economics only when traditional analytical solutions cannot be derived, i.e., only as a (...) purely computational aid. We argue that true simulation is seldom practiced because it does not fit the conception of understanding inherent in mainstream economics. According to this conception, understanding is constituted by analytical derivation from a set of fundamental economic axioms. We articulate this conception using the concept of economists' perfect model. Since the deductive links between the assumptions and the consequences are not transparent in ‘bottom‐up’ generative microsimulations, microsimulations cannot correspond to the perfect model and economists do not therefore consider them viable candidates for generating theories that enhance economic understanding. (shrink)

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)

This article presents a community-based account of salience as an alternative and a complement to the ‘natural salience’ approach which is endorsed by almost all game theorists who use this concept. While in the naturalistic approach, salience is understood as an objective and natural property of some entities, the community-based account claims that salience is a function of community membership. Building on David Lewis’s theory of common knowledge and on some of its recent refined accounts, I suggest that salience acts (...) as a correlating device in a correlated equilibrium. What is constitutive of salience is common understanding, the fact that agents have common knowledge that they share the same modes of reasoning with respect to a well-identified set of events. I argue that the basis for common understanding is community membership. The relevance of this account stems from the fact that it answers the objection that salience is either unnecessary or unable to account for coordination between rational agents. (shrink)

opinionated survey paper to be published in the Blackwell’s Philosophy Compass.

The development of evolutionary game theory is closely linked with two interdisciplinary exchanges: the import of game theory into biology, and the import of biologists’ version of game theory into economics. This paper traces the history of these two import episodes. In each case the investigation covers what exactly was imported, what the motives for the import were, how the imported elements were put to use, and how they related to existing practices in the respective disciplines. Two conclusions emerged from (...) this study. First, concepts derived from the unity of science discussion or the unification accounts of explanation are too strong and too narrow to be useful for analysing these interdisciplinary exchanges. Secondly, biology and economics—at least in relation to EGT—show significant differences in modelling practices: biologists seek to link EGT models to concrete empirical situations, whereas economists pursue conceptual exploration and possible explanation.Keywords: Models; Evolutionary game theory; Interdisciplinarity; Unification; Unity of science; Theory import; Biology; Economics. (shrink)

Some scholars see interdisciplinarity as a special case of a broader unificationist program. They accept the unification of the sciences as a regulative ideal, and derive from this the normative justification of interdisciplinary research practices. The crucial link for this position is the notion of integration: integration increases the cohesion of concepts and practices, and more specifically of explanations, ontologies, methods and data. Interdisciplinary success then consists in the integration of fields or disciplines, and this constitutes success in the sense (...) that unification is epistemically desirable. In contrast to this account, I defend the thesis that successful interdisciplinary interaction does not necessarily imply the integration of these disciplines. I show this at the hand of two cases. In both the case of evolutionary game theory and the case of hyperbolic discounting, genuine interdisciplinary exchange took place. From both exchanges, the respective economic fields emerged substantially altered – it wasn’t just a juxtaposition of disciplines in which disciplinary identities remained unchanged. Yet in neither case did the disciplines integrate. Rather, they developed their own concepts and methods, their own explanations, own ontologies, and their own views of what proper data standards were. Furthermore, the fields that emerged from these exchanges were very successful, if measured at the hand of properties like explanatory success, increase of control, bibliometrics and grant yields. Thus, I argue, there are cases of interdisciplinary success without integration. (shrink)

When social scientists began employing evolutionary game theory (EGT) in their disciplines, the question arose what the appropriate interpretation of the formal EGT framework would be. Social scientists have given different answer, of which I distinguish three basic kinds. I then proceed to uncover the conceptual tension between the formal framework of EGT, its application in the social sciences, and these three interpretations. First, I argue that EGT under the biological interpretation has a limited application in the social sciences, chiefly (...) because strategy replication often cannot be sensibly interpreted as strategy bearer reproduction in this domain. Second, I show that alternative replication mechanisms imply interpersonal comparability of strategy payoffs. Giving a meaningful interpretation to such comparisons is not an easy task for many social situations, and thus limits the applicability of EGT in this domain. Third, I argue that giving a new interpretation both to strategy replication and selection solves the issue of interpersonal comparability, but at the costs of making the new interpretation incompatible with natural selection interpretations of EGT. To the extent that social scientists seek such a natural selection interpretation, they face a dilemma: either face the challenge that interpersonal comparisons pose, or give up on the natural selection interpretation. By identifying these tensions, my analysis pleas for greater awareness of the specific purposes of EGT modelling in the social sciences, and for greater sensitivity to the underlying microstructure on which the evolutionary dynamics and other EGT solution concepts supervene. (shrink)

In recent years, several authors have reconstructed the relationship between 20th-century economic theory and neuro-psychological research in terms of a three-stage narrative of initial unity, increasing separation, and ongoing reunification. In this article, I draw on major developments in economic theory and neuro-psychological research to provide a descriptive and normative critique of this reconstruction. Moreover, I put forward a reconstruction of the relationship between economics and neuro-psychology that, I claim, better fits both the available empirical evidence and the methodological foundations (...) of these disciplines. In doing so, I argue that recent calls to develop a unified interdisciplinary framework for modeling choice are premised on disputable presuppositions concerning both the domain of economic theory and the relationship between this theory’s axiomatic foundations and empirical findings about the neuro-psychological substrates of choice. (shrink)

The problem of cooperation for rational actors comprises two sub problems: the problem of the intentional object (under what description does each actor perceive the situation?) and the problem of common knowledge for finite minds (how much belief iteration is required?). I will argue that subdoxastic signalling can solve the problem of the intentional object as long as this is confined to a simple coordination problem. In a more complex environment like an assurance game signals may become unreliable. Mutual beliefs (...) can then bolster the earlier attained equilibrium. I will first address these two problems by means of an example, in order to draw some more general lessons about combining evolutionary theory and rationality later on. (shrink)

Norms—that is, specifications of what we ought to do—play a critical role in the study of informal argumentation, as they do in studies of judgment, decision-making and reasoning more generally. Specifically, they guide a recurring theme: are people rational? Though rules and standards have been central to the study of reasoning, and behavior more generally, there has been little discussion within psychology about why (or indeed if) they should be considered normative despite the considerable philosophical literature that bears on this (...) topic. In the current paper, we ask what makes something a norm, with consideration both of norms in general and a specific example: norms for informal argumentation. We conclude that it is both possible and desirable to invoke norms for rational argument, and that a Bayesian approach provides solid normative principles with which to do so. (shrink)

Usually evolutionary economists equate evolutionary theory with modern Darwinism. However the rise of evolutionary developmental biology (Evo-Devo) puts into question the monopoly of Darwinism in evolutionary biology. The major divergences between the two paradigms in evolutionary biology are drawn in the analysis of three trade-offs: population vs. typological thinking, creative role of natural selection vs. internal (inherent) change, and microevolution vs. macroevolution. It is argued here that the Evo-Devo breakthrough helps to better understand the limits to Darwinism in the social (...) realm and design the contours of an alternative paradigm in evolutionary economics privileging structural macroevolution and what Schumpeter called “change from within”. (shrink)