The model of congestion games is widely used to analyze games related to traffic and communication. A central property of these games is that they are potential games and hence posses a pure Nash equilibrium. In reality, it is often the case that some players cooperatively decide on their joint action in order to maximize the coalition’s total utility. This is modeled by Coalitional Congestion Games. Typical settings include truck drivers who work for (...) the same shipping company, or routers that belong to the same ISP. The formation of coalitions will typically imply that the resulting coalitional congestion game will no longer posses a pure Nash equilibrium. In this paper, we provide conditions under which such games are potential games and posses a pure Nash equilibrium. (shrink)

Games associated with congestion situations à la Rosenthal have pure Nash equilibria. This result implicitly relies on the existence of a potential function. In this paper we provide a characterization of potential games in terms of coordination games and dummy games. Second, we extend Rosenthal's congestion model to an incomplete information setting, and show that the related Bayesian games are potential games and therefore have pure Bayesian equilibria.

When imposing traffic congestion pricing around downtown commercial centers, there is a concern that commercial activities will have to consider relocating due to reduced demand, at a cost to merchants. Concerns like these were important in the debates before the introductions of congestion charges in both London and Stockholm and influenced the final policy design choices. This study introduces a sequential experimental game to study reactions to congestion pricing in the commercial sector. In the game, merchants first (...) make location choices. Consumers, who drive to do their shopping, subsequently choose where to shop. Initial responses to the introduction of congestion pricing and equilibrium selection adjustments over time are observed. These observations are compared to responses and adjustments in a condition where congestion pricing is reduced from an initially high level. Payoffs are non-linear and non-transparent, making it less than obvious that the efficient equilibrium will be selected, and introducing possibilities that participants need to discover their preferences and anchor on past experiences. We find that initial responses reflect standard inverse price–demand relations, and that adjustments over time rely on signaling by consumers leading to the efficient equilibrium. There is also evidence that priming from initial experiences influence play somewhat. We confirm that commercial activities relocate following the introduction of congestion pricing and that the adjustment process is costly to merchants. (shrink)

Over the last 25 years, evolutionary game theory has grown with theoretical contributions from the disciplines of mathematics, economics, computer science and biology. It is now ripe for applications. In this book, Daniel Friedman---an economist trained in mathematics---and Barry Sinervo---a biologist trained in mathematics---offer the first unified account of evolutionary game theory aimed at applied researchers. They show how to use a single set of tools to build useful models for three different worlds: the natural world studied by biologists; the (...) social world studied by anthropologists, economists, political scientists and others; and the virtual world built by computer scientists and engineers. The first six chapters offer an accessible introduction to core concepts of evolutionary game theory. These include fitness, replicator dynamics, sexual dynamics, memes and genes, single and multiple population games, Nash equilibrium and evolutionarily stable states, noisy best response and other adaptive processes, the Price equation, and cellular automata. The material connects evolutionary game theory with classic population genetic models, and also with classical game theory. Notably, these chapters also show how to estimate payoff and choice parameters from the data. The last eight chapters present exemplary game theory applications. These include a new coevolutionary predator-prey learning model extending rock-paper-scissors; models that use human subject laboratory data to estimate learning dynamics; new approaches to plastic strategies and life cycle strategies, including estimates for male elephant seals; a comparison of machine learning techniques for preserving diversity to those seen in the natural world; analyses of congestion in traffic networks and the. (shrink)

The precautionary principle justifies postponing the implementation of development projects to await better information about their environmental impacts. But if implementation capacity is congestible, as is often the case in practical settings, a postponed project may have to vie for implementation priority with projects that arrive later. Limitations of implementation capacity create two risks. First, it may sometimes not make sense to go back to a postponed project, even if it is later revealed to be a good one. Second, the (...) planner may find it worthwhile to go back to it, but at the expense of undesirable delay of subsequent projects. We consider a planner facing a sequence of projects that vary stochastically in their (1) importance and (2) improvability, but knowing that implementation capacity is congestible. The scope for congestion implies a ‘bonus’ for earlier-than-otherwise decisions, in common parlance ‘keeping the desk clear’, which works against the well-understood option value that encourages postponement. The optimal decision rule depends upon the stochastic environment whereby future projects are generated, in ways that are not obvious. The value of the bonus is increasing in the expected importance of future projects but decreasing in their expected improvability. Higher variability of the importance of projects, in the sense of mean-preserving spread, increases the size of the bonus, but variability in their improvability has a generally ambiguous impact. We characterize the adjusted decision rule and note its implications for the conduct of cost-benefit informed policy. (shrink)

Following Schelling (1960), coordination problems have mainly been considered in a context where agents can achieve a common goal (e.g., rendezvous) only by taking common actions. Dynamic versions of this problem have been studied by Crawford and Haller (1990), Ponssard (1994), and Kramarz (1996). This paper considers an alternative dynamic formulation in which the common goal (dispersion) can only be achieved by agents taking distinct actions. The goal of spatial dispersion has been studied in static models of habitat selection, location (...) or congestion games, and network analysis. Our results show how this goal can be achieved gradually, by indistinguishable non-communicating agents, in a dynamic setting. (shrink)

We show that various paradoxes can arise in a natural class of social networks. They demonstrate that more services or products may have adverse consequences for all members of the network and conversely that restricting the number of choices may be beneficial for every member of the network. These phenomena have been confirmed by a number of empirical studies. In our analysis we use a simple threshold model of social networks introduced in Apt and Markakis, and more fully in Apt (...) and Markakis. In this model the agents, influenced by their neighbours, can adopt one out of several alternatives. We identify and analyze here four types of paradoxes that can arise in these networks. These paradoxes shed light on possible inefficiencies arising when one modifies the sets of products available to the agents forming a social network or the network structure. One of the paradoxes corresponds to the well-known Braess paradox in congestion games and shows that by adding more choices to a node, the network may end up in a situation that is worse for everybody. We exhibit a dual version of this, according to which removing a product available to an agent can eventually make everybody better off. The other paradoxes that we identify show that by adding or removing a product from the choice set of an agent may lead to permanent instability. Finally, we also identify conditions under which some of these paradoxes cannot arise. (shrink)

The Braess Paradox (BP) is a counterintuitive finding that degrading a network that is susceptible to congestion may decrease the equilibrium travel cost for each of its users. We illustrate this paradox with two networks: a basic network with four alternative routes from a single origin to a single destination, and an augmented network with six alternative routes. We construct the equilibrium solutions to these two networks, which jointly give rise to the paradox, and subject them to experimental testing. (...) Our purpose is to test the generality of the BP when the network is enriched as well as the effects of the information provided to the network users when they conclude their travel. To this end, we compare experimentally two information conditions when each of the two networks is iterated in time. Under public monitoring each user is accurately informed of the route choices and payoffs of all the users, whereas under private monitoring she is only informed of her own payoff. Under both information conditions, over iterations of the basic and augmented games, aggregate route choices converge to equilibrium. (shrink)

We argue that pedagogic authority relies on love, which is misunderstood if seen as a matter of actions and subjects. Love is based not on finite subjects and objects existing in Euclidean space and linear time, but, rather, on the non-finite ontology, space and time of relations. Loving authority is a matter of calling and vocation, arising from the spontaneous and simultaneous call-and-response of a lively relation. We make this argument through a reading of Buber’s I–You relation and Murdoch’ s (...) account of the responsiveness of ascetic discipline. In presenting this analysis, we draw upon a case study from a research project on Australian teachers and students. (shrink)

Through a phenomenological study of horse-human relations, this article explores the ways in which, as embodied beings, we live relationally, rather than as separate human identities. Conceptually this challenges oppositional logic and humanist assumptions, but where poststructuralist treatments of these issues tend to remain abstract, this article is concerned with an embodied demonstration of the ways in which we experience a relational or in-between logic in our everyday lives.

Prior research suggests brokers do not always act in the best interests of clients, although morally obligated to do so. We empirically investigated this issue focusing on trades executed at best execution price, before and after the introduction of electronic limit-order trading, on the London Stock Exchange. As a result of limit-order trading, the proportion of trades executed at the best execution price for the customer significantly increased. We attribute this to a sustained increase in the liquidity of stocks as (...) a result of limit-order trading, regardless of market capitalisation. We discuss the ethical implications of our findings and conclude that market structures that enhance market competitiveness may help reconcile broker and client interests. (shrink)

This study examined the link between employees’ adult attachment orientations and perceptions of line managers’ interpersonal justice behaviors, and the moderating effect of national culture. Participants from countries categorized as low collectivistic and high collectivistic completed an online survey. Attachment anxiety and avoidance were negatively related to interpersonal justice perceptions. Cultural differences did not moderate the effects of avoidance. However, the relationship between attachment anxiety and interpersonal justice was non-significant in the Southern Asia cultural cluster. Our findings indicate the importance (...) of ‘fit’ between cultural relational values and individual attachment orientations in shaping interpersonal justice perceptions, and highlight the need for more non-western organizational justice research. (shrink)

We consider how cue-reading, sensory-manipulation, and signaling games may initially evolve from ritualized decisions and how more complex games may evolve from simpler games by polymerization, template transfer, and modular composition. Modular composition is a process that combines simpler games into more complex games. Template transfer, a process by which a game is appropriated to a context other than the one in which it initially evolved, is one mechanism for modular composition. And polymerization is a (...) particularly salient example of modular composition where simpler games evolve to form more complex chains. We also consider how the evolution of new capacities by modular composition may be more efficient than evolving those capacities from basic decisions. (shrink)

A comprehensive examination of the interfaces of logic, computer science, and game theory, drawing on twenty years of research on logic and games.

We introduce frame-equivalence games tailored for reasoning about the size, modal depth, number of occurrences of symbols and number of different propositional variables of modal formulae defining a given frame property. Using these games, we prove lower bounds on the above measures for a number of well-known modal axioms; what is more, for some of the axioms, we show that they are optimal among the formulae defining the respective class of frames.

In the mid twentieth century the philosopher Ludwig Wittgenstein famously asserted that games are indefinable; there are no common threads that link them all. "Nonsense," says the sensible Bernard Suits: "playing a game is a voluntary attempt to overcome unnecessary obstacles." The short book Suits wrote demonstrating precisely that is as playful as it is insightful, as stimulating as it is delightful. Suits not only argues that games can be meaningfully defined; he also suggests that playing games (...) is a central part of the ideal of human existence, so games belong at the heart of any vision of Utopia. Originally published in 1978, The Grasshopper is now re-issued with a new introduction by Thomas Hurka and with additional material (much of it previously unpublished) by the author, in which he expands on the ideas put forward in The Grasshopper and answers some questions that have been raised by critics. (shrink)

The aim of this paper is to provide a preliminary defence of the use of the concept of dignity in legal and ethical discourse. This will involve the application of three philosophical insights: (1) Ludwig Wittgenstein’s notion of language-games; (2) his related approach to understanding the meanings of words (sometimes summarised as ‘meaning is use’); and (3) Jeremy Waldron’s layered understanding of property wherein ‘property’ consists in an abstract concept fleshed out in numerous particular conceptions. These three insights will (...) be applied, in the first place, to the concept of ‘dignity’, which is chosen here as a good example of a concept which is both vague and contested in legal and ethical discourse, but which can nevertheless be rendered workable by the application of the aforementioned insights. Later, the analysis will be extended briefly to some other troublesome concepts in order to demonstrate its general application. This paper is concerned primarily with formal, rather than substantive questions about dignity. Matters of content will be touched on only insofar as is necessary to illustrate and illuminate my argument about how we ought to approach (rather than answer) questions about dignity. It should be emphasised that because there is no intention of exploring substantive questions in any depth, the discussion here will not delve into the criticisms of ‘speciesism’ often levelled against the idea of ‘human dignity’. ‘Speciesist’ theories are those that claim that the status, value, or rights of human beings can be regarded as being higher than that of other animals, purely on the basis of their membership of the human species, and without justifying the distinction by pointing to any relevant capacity or characteristic possessed by all and only human beings. For a critical description of speciesism see, e.g., Singer [18] Chapter Three passim; for present purposes, the term ‘dignity’ will be used synonymously with ‘human dignity’, and concerns about speciesism will not be considered. (shrink)

Signalling games are popular models for studying the evolution of meaning, but typical approaches do not incorporate vagueness as a feature of successful signalling. Complementing recent like-minded models, we describe an aggregate population-level dynamic that describes a process of imitation of successful behaviour under imprecise perception and realization of similar stimuli. Applying this new dynamic to a generalization of Lewis’s signalling games, we show that stochastic imprecision leads to vague, yet by-and-large efficient signal use, and, moreover, that it (...) unifies evolutionary outcomes and helps avoid sub-optimal categorization. The upshot of this is that we see ‘as-if’-generalization at an aggregate level, without agents actually generalizing. _1_ Introduction _2_ Background _2.1_ Sim-max games and conceptual spaces _2.2_ Vagueness in sim-max games and conceptual spaces _2.3_ Vagueness, functional pressure, and transmission biases _3_ Imprecise Imitation _3.1_ Replicator dynamic in behavioural strategies _3.2_ Noise-perturbed conditional imitation _4_ Exploring Imprecise Imitation _4.1_ Setting the stage _4.2_ Simulation set-up _4.3_ Measures of interest _4.4_ Results _5_ Discussion _5.1_ Levels of vagueness _5.2_ Evolutionary benefits of imprecision _5.3_ Related work _6_ Conclusion Appendix. (shrink)

Godfrey-Smith advocates for linking deception in sender-receiver games to the existence of undermining signals. I present games in which deceptive signals can be arbitrarily frequent, without this undermining information transfer between sender and receiver.

In conversations with Schlick and Waismann from June and December 1930, Wittgenstein began to turn his attention to the topic of games. This topic also centrally concerned Schlick. In his earliest philosophical output, Schlick had relied on the results of evolutionary biology in setting out an account of the emergence of the human species’ ability to play [Spiel] as a prerequisite for the genesis of scientific knowledge. Throughout his subsequent works one finds fragmentary appeals to this early view, e.g. (...) in his oft misunderstood claim that play constitutes the meaning of life. Wittgenstein’s turn to the topic of games in 1930 not only happened while Professor Schlick was in the room, but was also coupled with an explicit response to Schlick’s 1930 book Fragen der Ethik. Schlick here employs the example of chess to distinguish between rules and their application – a distinction which underlies his whole attempt to naturalise ethics as a descriptive psycho-sociological discipline. This paper investigates the relation between Wittgenstein’s and Schlick’s accounts of games in light of Wittgenstein’s criticisms of Schlick’s ethics. Wittgenstein’s objections can be answered by taking Schlick’s theory of play into consideration. (shrink)

This article considers how a generalized signalling game may self-assemble as the saliences of the agents evolve by reinforcement on those sources of information that in fact lead to successful action. On the present account, generalized signalling games self-assemble even as the agents co-evolve meaningful representations and successful dispositions for using those representations. We will see how reinforcement on successful information sources also provides a mechanism whereby simpler games might compose to form more complex games. Along the (...) way, I consider how an old game might be appropriated to a new context by reinforcement on successful associations between old and new saliences. (shrink)

This chapter focuses on a widely held package of views, according to which: (i) assertions are governed by some alethic or epistemic norm, (ii) such a norm is intimately connected to assertion, in the sense that it individuates or characterizes the speech act, and (iii) this sense of intimate connection can be explained with the help of an analogy between language use and games. It is argued that this package of views must be rejected. More specifically, by considering some (...) different ways of spelling out the analogy mentioned in (iii), it is shown that at least that part of the package must be abandoned: even if some alethic or epistemic norm is intimately connected to assertion, that relationship is not mirrored by the relationship between norms and the games they govern. (shrink)

We consider how cue-reading, sensory-manipulation, and signaling games may initially evolve from ritualized decisions and how more complex games may evolve from simpler games by polymerization, template transfer, and modular composition. Modular composition is a process that combines simpler games into more complex games. Template transfer, a process by which a game is appropriated to a context other than the one in which it initially evolved, is one mechanism for modular composition. And polymerization is a (...) particularly salient example of modular composition where simpler games evolve to form more complex chains. We also consider how the evolution of new capacities by modular composition may be more efficient than evolving those capacities from basic decisions. (shrink)

Although the word empathy only recently came into existence, eighteenth century philosopher, David Hume, significantly contributed to our current understanding of the term. Hume was among the first to suggest that an empathic mechanism is the central means by which we make ethical judgments and glean moral knowledge. In this paper, I explore Hume's moral sentimentalism, and I argue that his conception of empathy provides a surprisingly apposite framework for interpreting and addressing a current issue in practical ethics: the moral (...) significance of ultra-violent video games. Ultimately, I attempt to show that a Humean account of morality uniquely explains the dangers of ultra-violent video gaming by elucidating a direct connection between playing such games and moral harm. (shrink)

In previous work I’ve defended an interest-relative theory of belief. This paper continues the defence. It has four aims. -/- 1. To offer a new kind of reason for being unsatis ed with the simple Lockean reduction of belief to credence. 2. To defend the legitimacy of appealing to credences in a theory of belief. 3. To illustrate the importance of theoretical, as well as practical, interests in an interest-relative account of belief. 4. To revise my account to cover propositions (...) that are practically and theoretically irrelevant to the agent. (shrink)

Pragmatic encroachment theories have a problem with evidence. On the one hand, the arguments that knowledge is interest-relative look like they will generalise to show that evidence too is interest-relative. On the other hand, our best story of how interests affect knowledge presupposes an interest-invariant notion of evidence. -/- The aim of this paper is to sketch a theory of evidence that is interest-relative, but which allows that ‘best story’ to go through with minimal changes. The core idea is that (...) the evidence someone has is just what evidence a radical interpreter says they have. And a radical interpreter is playing a kind of game with the person they are interpreting. The cases that pose problems for pragmatic encroachment theorists generate fascinating games between the interpreter and the interpretee. They are games with multiple equilibria. To resolve them we need to detour into the theory of equilibrium selection. I’ll argue that the theory we need is the theory of risk-dominant equilibria. That theory will tell us how the interpreter will play the game, which in turn will tell us what evidence the person has. The evidence will be interest-relative, because what the equilibrium of the game is will be interest-relative. But it will not undermine the story we tell about how interests usually affect knowledge. (shrink)

Philosophy has a schizophrenic relationship with games. On the one hand, philosophers love using games as model, arguing that phenomena as diverse as linguistic meaning, meta‐ethics, normative ethics, applied ethics, law, and aesthetics can be illuminated via an analogy with games. On the other hand, there is scant focused discussion of the concept of a game as such. This is problematic; the appeal to games as a model to clarify philosophically puzzling questions has limited utility if (...) games themselves (and the concept of a game) are poorly understood. Moreover, playing games plausibly is an important element in a good life; anyone interested in the theory of welfare, a traditional philosophical topic, should be interested in games. We play games, but if anything, play itself has been more neglected by philosophers than games. This neglect is unwarranted. Historically, philosophy has investigated foundational questions about human nature, and a disposition to play plausibly is a deep part of human nature. Moreover, play is an important concept in evolutionary biology and psychology, yet those working in those fields struggle to define the concept to their own satisfaction. E.O. Wilson went so far as to remark that “no behavioural concept has proved more ill‐defined, elusive, controversial, and even unfashionable than play.” One might have hoped philosophers could help here. In this paper, I provide an opinionated introduction to the philosophy of play and games. (shrink)

In this essay we argue that there is a contradiction lurking at the heart of Bernard Suits's seminal book on the philosophy of games, The Grasshopper, which has oddly gone unnoticed for 43 years. Suits argues that games need inefficiency and defines inefficiency such that it wouldn't exist in Utopia. This trivially entails that there could be no games in Utopia, yet the whole normative point of The Grasshopper is that games would be the only worthwhileactivity (...) in Utopia. We then diagnose Suits's error and suggest some ways forward. (shrink)

The mechanisms responsible for the fine tuning of development, where the wildtype phenotype is reproduced with high fidelity, are not well understood. The difficulty in approaching this problem is the identification of mutant phenotypes indicative of a defect in these fine‐tuning control mechanisms. Evolutionary biologists have used asymmetry as a measure of developmental homeostasis. The rationale for this was that, since the same genome controls the development of the left and right sides of a bilaterally symmetrical organism, departures from symmetry (...) can be used to measure genetic or environmental perturbations. This paper examines the relationship between asymmtry and resistance to organophosphorous insecticides in the Australian sheep blowfly, Lucilia cuprina. A resistance gene, Rop‐1, which encodes a carboxylesterase enzyme, also confers a significant increase in asymmetry. Continued exposure of resistant populations to insecticide has selected a dominant suppressor of the asymmetry phenotype. Genetic evidence indicates that the modifier is the L. cuprina Notch homologue. (shrink)

commentary on Fodor, “Against Darwinism.”.

It is widely agreed that humans have specific abilities for cooperation and culture that evolved since their split with their last common ancestor with chimpanzees. Many uncertainties remain, however, about the exact moment in the human lineage when these abilities evolved. This article argues that cooperation and culture did not evolve in one step in the human lineage and that the capacity to stick to long-term and risky cooperative arrangements evolved before properly modern culture. I present evidence that Homo heidelbergensis (...) became increasingly able to secure contributions form others in two demanding Paleolithic public good games (PPGGs): cooperative feeding and cooperative breeding. I argue that the temptation to defect is high in these PPGGs and that the evolution of human cooperation in Homo heidelberngensis is best explained by the emergence of modern-like abilities for inhibitory control and goal maintenance. These executive functions are localized in the prefrontal cortex and allow humans to stick to social norms in the face of competing motivations. This scenario is consistent with data on brain evolution that indicate that the largest growth of the prefrontal cortex in human evolution occurred in Homo heidelbergensis and was followed by relative stasis in this part of the brain. One implication of this argument is that subsequent behavioral innovations, including the evolution of symbolism, art, and properly cumulative culture in modern Homo sapiens , are unlikely to be related to a reorganization of the prefrontal cortex, despite frequent claims to the contrary in the literature on the evolution of human culture and cognition. (shrink)

We study partiality in propositional logics containing formulas with either undefined or over-defined truth-values. Undefined values are created by adding a four-place connective W termed transjunction to complete models which, together with the usual Boolean connectives is shown to be functionally complete for all partial functions. Transjunction is seen to be motivated from a game-theoretic perspective, emerging from a two-stage extensive form semantic game of imperfect information between two players. This game-theoretic approach yields an interpretation where partiality is generated as (...) a property of non-determinacy of games. Over-defined values are produced by adding a weak, contradictory negation or, alternatively, by relaxing the assumption that games are strictly competitive. In general, particular forms of extensive imperfect information games give rise to a generalised propositional logic where various forms of informational dependencies and independencies of connectives can be studied. (shrink)

A mistake in “Five legitimate definitions of correlated equilibrium (CE) in games with incomplete information” motivates a re-examination of some extensions of the solution concept that Aumann introduced.