The aim of the paper is the construction of a distributional model which enables the study of the evolutionary dynamics that arise for symmetric games, and the equilibrium selection mechanisms that originate from such processes. The evolution of probability distributions over the state variables is studied using the Fokker-Planck diffusion equation. Equilibrium selection using the ’’basin of attraction’’ approach, and a selection process suggested by Pontryagin are contrasted. Examples are provided for all generic 2-person symmetric (...) binary choice games. JEL Classification: C78.. (shrink)

Axelord’s [(1970), Conflict of Interest, Markham Publishers, Chicago] index of conflict in 2 × 2 games with two pure strategy equilibria has the property that a reduction in the cost of holding out corresponds to an increase in conflict. This article takes the opposite view, arguing that if losing becomes less costly, a player is less likely to gamble to win, which means that conflict will be less frequent. This approach leads to a new power index and a new measure (...) of stubbornness, both anchored in strategic reasoning. The win probability defined as power constitutes an equilibrium refinement which differs from Harsanyi and Selten’s [(1988), A General Theory of Equilibrium Selection in Games, MIT Press, Cambridge] refinement. In contrast, Axelrod’s approach focuses on preferences regarding divergences from imaginary outmost rewards that cannot be obtained jointly. The player who is less powerful in an asymmetric one-shot game becomes more powerful in the repeated game, provided he or she values the future sufficiently more than the opponent. This contrasts with the view that repetition induces cooperation, but conforms with the expectation that a more patient player receives a larger share of the pie. (shrink)

The theoretical literature on vertical relationships usually assumes that beliefs about secret contracts take specific forms. In a recent paper, Eguia et al. (Games Econ Behav 109:465–483,2018) propose a new selection criterion that does not impose any restriction on beliefs. In this article, we extend their criterion by generalizing it to risk-averse retailers, and we show that risk aversion modifies the size of the belief subsets that support each equilibrium. We conduct an experiment which revisits that of Eguia (...) et al. (Games Econ Behav 109:465–483,2018). We design a new treatment effect on equilibrium selection depending on the retailers’ risk sensitivity. Experimental results confirm the treatment effect: the more sensitivity there is towards risk, the more the equilibrium played is consistent with passive beliefs. In addition, extending Eguia et al.’s (Games Econ Behav 109:465–483,2018) criterion to risk-averse retailers improves its predictive power on the equilibria played, especially for a population of retailers with moderate to extreme risk aversion. (shrink)

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)

The paper is an addition to the intensionalist approach to decision theory, with emphasis on game theoretic modelling. Extensionality in games is an a priori requirement that players exhibit the same behavior in all algebraically equivalent games on pain of irrationality. Intensionalism denies that it is always irrational to play differently in differently represented but algebraically equivalent versions of a game. I offer a framework to integrate game non-extensionality with the more familiar idea of linguistic non-extensionality from philosophy of language, (...) followed by applications of it based on toy examples of well-known game models. I argue that the notion of what I call “Intensional Nash Equilibrium” is, in effect, very useful in understanding human decision-making. (shrink)

In this paper, we focus on one controversial element of the method of reflective equilibrium, namely Rawls’s idea that the commitments that enter the justificatory procedure should be pre-selected or filtered: According to him, only considered judgements should be taken into account in moral philosophy. There are two camps of critics of this filtering process: 1) Critics of reflective equilibrium: They reject the Rawlsian filtering process as too weak and seek a more reliable one, which would actually constitute (...) a distinct epistemic method. 2) Proponents of reflective equilibrium: They reject the Rawlsian filtering process as too exclusionary. We defend RE against its critics, arguing that the method can secure reasonable commitments without depending on a strong external filtering process. However, we side with the critical proponents of reflective equilibrium and argue that without the Rawlsian weak filtering process, RE is more plausible both as a general method as well as in the context of moral philosophy. (shrink)

Influential neoclassical economist Lionel McKenzie has made major contributions to postwar economic thought in the fields of equilibrium, trade, and capital accumulation. This selection of his papers traces the development of his thinking in these three crucial areas.McKenzie's early academic life took him to Duke, Princeton, Oxford, the University of Chicago, and the Cowles Commission. In 1957, he went to the University of Rochester to head the economics department there, and he remains at Rochester, now Wilson Professor Emeritus (...) of Economics. McKenzie's most significant research was undertaken during a period that saw the development of the major themes of neoclassical economics and the use of fundamental mathematical methods to do so. McKenzie contributed to both aspects of this research program. He helped shape the direction of the field and, at Rochester, influenced generations of future scholars. In 2002, The MIT Press published McKenzie's Classical General Equilibrium Theory, a detailed summary of the model and methodology. This book, collecting his most important papers in the form in which they were originally published, can be seen as a companion to that one. The many state-of-the-art results achieved in McKenzie's original papers present sophisticated theoretical work that will continue to be important to future developments in the discipline. (shrink)

It is an ongoing controversy whether natural selection is a cause of population change, or a mere statistical description of how individual births and deaths accumulate. In this paper I restate the problem in terms of the reference class problem, and propose how the structure of stable equilibrium can provide a solution in continuity with biological practice. Insofar natural selection can be understood as a tendency towards equilibrium, key statisticalist criticisms are avoided. Further, in a modification (...) of the Newtonian-force analogy, it can be suggested that a better metaphor for natural selection is that of an emergent force, similar in nature to entropic forces: with magnitude and direction, but lacking a spatiotemporal origin or point of application. (shrink)

In political philosophy, reflective equilibrium is a standard method used to systematically reconcile intuitive judgments with theoretical principles. In this paper, we propose that survey experiments and a model selection method—i.e., the Akaike Information Criterion (AIC)-based model selection method—can be viewed together as a methodological means of satisfying the epistemic desiderata implicit in reflective equilibrium. To show this, we conduct a survey experiment on two theories of distributive justice, prioritarianism and sufficientarianism. Our experimental test case and (...) AIC-based model selection method demonstrate that the refined sufficientarian principle, a widely accepted principle of distributive justice, is no more plausible than the prioritarian principle. This tells us that some changes of certain intuitions revolving around sufficientarianism should be examined (separately) based on the findings of the survey experiment and AIC model selection. This shows the potential of our approach—both practically and methodologically—as a novel way of applying reflective equilibrium in political philosophy. (shrink)

Betty Joseph's work has become an outstanding influence in the development and theory of psychoanalytic technique in the Kleinian tradition. This collection of her most important papers examines the development of her thought and shows why a crucial part of her theory and practice is concerned with the detailed, sensitive scrutiny of the therapeutic process itself. Fundamental and controversial topics explored and discussed include projective identification, transference and countertransference, unconscious phantasy, and Kleinian views on envy and the death instinct.

This book, collecting his most important papers in the form in which they were originally published, can be seen as a companion to that one.

ABSTRACT In ethics, the use of empirical data has become more and more popular, leading to a distinct form of applied ethics, namely empirical ethics. This ‘empirical turn’ is especially visible in bioethics. There are various ways of combining empirical research and ethical reflection. In this paper we discuss the use of empirical data in a special form of Reflective Equilibrium (RE), namely the Network Model with Third Person Moral Experiences. In this model, the empirical data consist of the (...) moral experiences of people in a practice. Although inclusion of these moral experiences in this specific model of RE can be well defended, their use in the application of the model still raises important questions. What precisely are moral experiences? How to determine relevance of experiences, in other words: should there be a selection of the moral experiences that are eventually used in the RE? How much weight should the empirical data have in the RE? And the key question: can the use of RE by empirical ethicists really produce answers to practical moral questions? In this paper we start to answer the above questions by giving examples taken from our research project on understanding the norm of informed consent in the field of pediatric oncology. We especially emphasize that incorporation of empirical data in a network model can reduce the risk of self‐justification and bias and can increase the credibility of the RE reached. (shrink)

Equilibrium explanations use an equilibrium to represent and explain a system’s dynamic behavior. They provide a system with the property of global stability: a system will converge towards and remain in equilibrium regardless of its initial conditions and dynamic process. Thus, equilibrium explanations are generally treated as non-causal explanations. There are two claims subsumed under that comprehensive thesis. The first claim is that equilibrium explanations do not identify any causes because a system with global stability (...) resists manipulation. The second claim is that even if equilibrium explanations do identify causes by manipulation, those causes are embedded in a system’s deeper, underlying structural relationships, and those causes are irrelevant to explaining a system’s behavior. Only the system’s structural relationships are relevant. But equilibrium explanations are not monolithic. I compare dynamic systems with multiple, competing equilibria to systems with a globally stable equilibrium. Equilibrium explanations of the former use intervention on a system’s initial conditions and dynamic process to manipulate equilibria, which identifies causes. Furthermore, a system’s initial conditions and dynamic process are relevant to explaining why one equilibrium is selected instead of another. I then apply these lessons to systems with a globally stable equilibrium and discuss when their corresponding equilibrium explanations have a proper role in the parent sciences. (shrink)

Aconvention is a state in which agents coordinate their activity, not as the result of an explicit agreement, but because their expectations are aligned so that each individual believes that all will act so as to achieve coordination for mutual benefit. Since agents are said to follow a convention if they coordinate without explicit agreement, the notion raises fundamental questions: (1) Why do certain conventions remain stable over time?, and (2) How does a convention emerge in the first place? In (...) a pioneering study, Lewis (1969) addresses these questions by applyingnoncooperative game theory. Lewis defines a convention as aNash coordination equilibrium of a noncooperative game that issalient, that is, it is somehow conspicuous to the agents so that all expect one another to conform with the equilibrium. This paper presents a new game theoretic definition of conventions, which formalizes the notion of salience and which also generalizes the class of conventions Lewis discusses in his work. I define a convention as acorrelated equilibrium (Aumann 1974, 1987) satisfying apublic intentions criterion: Every agent wants his intended action to becommon knowledge. I argue that many conventions correspond to correlated equilibria that are not Nash equilibria, and that this is consistent with Lewis' general viewpoint. Finally, I argue that game theoretic characterizations of convention, such as Lewis' and my own, help to explain a convention's stability, but that a fully satisfactory account of the emergence of convention requires a theory of equilibrium selection beyond the scope of Lewis' work. (shrink)

Mixed-strategy equilibria are typically rather unstable in evolutionary game theory. “Monocyclic” games, such as Rock–Paper–Scissors, have only mixed equilibria, some of which are “stable” in the sense that sequential best replies lead to them; yet, even these games are prone to stable cycles under discrete-time simultaneous best replies, giving an unusual equilibrium-selection problem. This article analyzes such games in a random-utility setting where changing strategies is costly, and the speed of the dynamic is, thus, endogenous. The stochastically stable (...) outcome is determined by the cost of switching strategies; when switching costs are high, mixed equilibria are selected, whereas when switching costs are low, cycles are selected. (shrink)

Consistency and optimality together with converse consistency provide an illuminating and novel characterization of the equilibrium concept (Peleg and Tijs, 1996). But (together with non-emptiness) they preclude refinements of the equilibrium notion and selection of a unique equilibrium (Norde et al., 1996). We suggest two escape routes: By generalizing the concept of strict equilibrium we question the practical relevance of the existence requirement for refinements. To allow for equilibrium selection we suggest more complex (...) reduced games which capture the inclinations of ``players who already left''. (shrink)

In ethics, the use of empirical data has become more and more popular, leading to a distinct form of applied ethics, namely empirical ethics. This 'empirical turn' is especially visible in bioethics. There are various ways of combining empirical research and ethical reflection. In this paper we discuss the use of empirical data in a special form of Reflective Equilibrium (RE), namely the Network Model with Third Person Moral Experiences. In this model, the empirical data consist of the moral (...) experiences of people in a practice. Although inclusion of these moral experiences in this specific model of RE can be well defended, their use in the application of the model still raises important questions. What precisely are moral experiences? How to determine relevance of experiences, in other words: should there be a selection of the moral experiences that are eventually used in the RE? How much weight should the empirical data have in the RE? And the key question: can the use of RE by empirical ethicists really produce answers to practical moral questions? In this paper we start to answer the above questions by giving examples taken from our research project on understanding the norm of informed consent in the field of pediatric oncology. We especially emphasize that incorporation of empirical data in a network model can reduce the risk of self-justification and bias and can increase the credibility of the RE reached. (shrink)

Vanderschraaf develops a new theory of game theory equilibrium selection in this book. The new theory defends general correlated equilibrium concepts and suggests a new analysis of convention.

Dual-process theories of the mind emphasize how reasoning is an interplay between intuitive and reflective thinking. This paper aims to understand how the two types of processing interact in the moral domain. According to a ‘default-interventionist’ model of moral reasoning intuition and reflection are conflicting cognitions: intuitive thinking would elicit heuristic and deontological responses, whereas reflection would favour utilitarian judgements. However, the evidence for the default interventionist view is inconclusive and challenged by a growing amount of counterevidence in recent years. (...) The recent empirical findings favour an interdependent rather than conflicting view of the two types of information processing in the moral domain. In this view, which I call dual-process reflective equilibrium, intuition and reflection cooperate in moral reasoning to reach a reflective goal, which is supposedly normative justification. In sum, on the one hand, the scope of moral intuitions extends to selecting relevant information and calling for reflection whenever a problem presents conflicting aspects; on the other hand, the purpose of moral reflection is to rationalize pre-reflective intuitions to provide articulated and accessible reasons. (shrink)

The problem of modifier evolution was examined with regard to the idea that modifier evolution can be considered as a result of selection for adaptation speed in populations far from equilibrium. This kind of selection was called feedback selection in order to emphasize the difference to theories which consider modifier evolution near the equilibrium. The basic principles of this kind of selection are derived for asexual populations and the problem of dominance is discussed in (...) the light of this concept. In general the results support the view, that the genetic properties of a character are selected along with the character itself. (shrink)

We consider the Stag Hunt in terms of Maynard Smith’s famous Haystack model. In the Stag Hunt, contrary to the Prisoner’s Dilemma, there is a cooperative equilibrium besides the equilibrium where every player defects. This implies that in the Haystack model, where a population is partitioned into groups, groups playing the cooperative equilibrium tend to grow faster than those at the non-cooperative equilibrium. We determine under what conditions this leads to the takeover of the population by (...) cooperators. Moreover, we compare our results to the case of an unstructured population and to the case of the Prisoner’s Dilemma. Finally, we point to some implications our findings have for three distinct ideas: Ken Binmore’s group selection argument in favor of the evolution of efficient social contracts, Sewall Wright’s Shifting Balance theory, and the equilibrium selection problem of game theory. (shrink)

The paper studies equilibrium contracts under adverse selection when there is repeated interaction between a principal and an agent over an infinite horizon, without commitment across periods. We show the second-best contract is offered in a perfect Bayesian equilibrium of the infinite horizon model. Unlike the equilibrium contracts in the finite-horizon, the equilibrium contracts in the infinite horizon are not subject to either the ratchet effect or take-the-money-and-run strategy, but rely on a carrot and stick (...) strategy. We study two important applications, one of which is about the optimal regulation of a publicly-held firm. This application has a mixture of both moral hazard and adverse selection. The other application is to the problem of optimal nonlinear pricing when the valuation of the buyers are drawn from a continuum. (shrink)

The Hardy–Weinberg equilibrium has been argued by Sober, Stephens and others to represent the zero-force state for evolutionary biology understood as a theory of forces. I investigate what it means for a model to involve forces, developing an explicit account by defining what the zero-force state is in a general theoretical context. I use this account to show that Hardy–Weinberg equilibrium is not the zero-force state in biology even in the contexts in which it applies, and argue based (...) on this that drift should not be understood as an evolutionary force. (shrink)

How should we proceed when searching for justified answers to normative questions? A prominent proposal is to use the method of reflective equilibrium (RE). Its basic Idea—that we should start from our existing judgments about relevant cases and bring them into equilibrium with systematic principles—is readily recited, but beyond that, conceptions of RE often stay sketchy. RE is seldom explicitly implemented, which makes it difficult to critically evaluate the method and to assess its potential. In my dissertation, I (...) present the first explicit and detailed case study for an application of RE, using it to develop and defend a precautionary principle. -/- The dissertation is divided in two parts, a theoretical and an applied part. In part I, I introduce and operationalize a specific conception of RE. I first describe the central elements of RE by drawing on the most elaborate and fleshed-out conceptions of RE that can be found in the literature. Then, I survey and analyze previous applications of RE in order to both learn from them and identify desiderata for my own case study. Based on a small-scale, exploratory case study, the method is further concretized and operationalized for the implementation in my main case study on the justification of a precautionary principle. -/- In part II, this operationalization is tested in a complex case study that aims at justifying a precautionary principle which is applicable to problems arising from global climate change. In order to be able to select relevant commitments about central problems concerning precautionary principles (PPs), I start with a literature survey. The survey gives an overview on existing proposals for PPs, on which grounds they are defended, and the main objections against them. On this basis, I develop and describe the initial setup for the case study, which is conducted in three main steps and allows to examine different aspects of a RE-application. Thereby, I show that RE can be applied successfully to real problems. I go on to discuss a number of points that are not given sufficient attention in the RE literature so far. With respect to precautionary principles, I show how the commonly discussed principles fail to do justice to ethical considerations, and argue that the application of such principles should instead be triggered by threats of rights violations. (shrink)

Reflective equilibrium is often credited with extending the idea of accounting for the data from its familiar home in the sciences to the realm of moral philosophy. But careful consideration of the main concepts of this idea—the data to be accounted for and the kind of accounting it is appropriate to expect of a moral theory—leads to a revised understanding of the “accounting for the data” perspective as it applies to the discipline of moral theory selection. This revised (...) understanding is in tension with reflective equilibrium and actually provides more support for the alternative method of moral theory selection that has been termed ‘practical equilibrium’. (shrink)

The architects of punctuated equilibrium and species selection as well as more recent workers (Vrba) have narrowed the original formulation of species selection and made it dependent upon so-called emergent characters. One criticism of this narrow version is the dearth of emergent characters with a consequent diminution in the robustness of species selection as an important evolutionary process. We argue that monomorphic species characters may at times be the focus of selection and that under these (...) circumstances selection at the organism level is by-passed due to the absence of critical variance. Selection therefore shifts to the species level where variability reemerges in a clade. The absence of critical variance among organisms prevents effect macroevolution from operating. If species-wide properties are important in macroevolutionary processes, as we contend, systematists should pay more attention to their elucidation. (shrink)

The prelims comprise: Strategic Interaction Nash Equilibrium Normal‐form Refinements Games in Extensive Form Extensive‐form Refinements Selection by Evolution Notes.

This article argues that, suitably modified, the method of reflective equilibrium is a plausible way of selecting moral principles. The appropriate conception of the method is wide and radical, admitting consideration of a full range of moral principles and arguments, and requiring the enquiring individual to consider others' views and undergo experiences that may offset any formative biases. The individual is not bound by his initial considered judgments, and may revise his view in any way whatsoever. It is appropriate (...) to describe the method as a balance between coherentism and fallibilist foundationalism. With these points in mind, various criticisms, including the claims that considered judgments are not initially credible and are shaped by prejudice, and that the method itself fails to determine principle selection, are challenged. (shrink)

In the target article, Christie, Brusse, et al. argue that selected effect functions do not, in general, explain why a trait exists in a population and, therefore, theories of representational content should not rely on selected effect functions. This response focuses on the claim about functions-for-representation. The role of evolutionary functions in a theory of content is to pick out outcomes that have been systematically stabilized by natural selection. Correctness conditions are conditions involved in explaining how that happened. Selected (...) effect functions can play that role in the complex equilibria that Christie, Brusse, et al. identify. Non-equilibrium cases are also discussed. (shrink)

This paper presents a survey on contemporary RC accounts of norms. The characteristic common feature of these accounts is that norms are understood as equilibrium selection devices. The most sophisticated positions driven by this idea are Herbert Gintis’ theory of norms as choreographers and Cristina Bicchieri’s theory of norms as solutions to mixed motive games. In order to give a comprehensive account of social norms, though, RC theory needs to be substantially extended. In particular, it seems to be (...) impossible in principle to fully understand the concept of normativity and the motivating power of norms within a traditional, pure RC framework. (shrink)

Virtual bargaining theory suggests that social agents aim to resolve non-cooperative games by identifying the strategy profile which they would agree to play if they could openly bargain. The theory thus offers an explanation of how social agents resolve games with multiple Nash equilibria. One of the main questions pertaining to this theory is how the principles of the bargaining theory could be applied in the analysis of hypothetical bargaining in non-cooperative games. I propose a bargaining model based on the (...) benefit-equilibrating bargaining solution concept for non-cooperative games, broadly in line with the principles underlying Conley and Wilkie's ordinal egalitarian solution for Pareto optimal point selection problems with finite choice sets. I provide formal characterizations of the ordinal and the cardinal versions of BES, discuss their application to n-player games, and compare model's theoretical predictions with the data available from several experiments involving `pie games'. (shrink)

This research implements a recent evolutionary-based algorithm of equilibrium optimizer to resolve the constrained combined economic emission dispatch problem. This problem has two objective functions that represent the minimizing of generation costs and minimizing the emission of environmental pollution caused by generators. The proposed algorithm integrates the dominant criteria for multiobjective functions that allow the decision-maker to detect all the Pareto boundaries of constrained combined economic emission dispatch problem. In order to save the effort for the decision-maker to select (...) the best compromise alternative, a cluster study was carried out to minimize the size of the Pareto boundary to an acceptable size, representing all the characteristics of the main Pareto frontier. On the other hand, in order to deal with the infringement of constraints, a repair algorithm was used to preserve the viability of the particles. The proposed algorithm is applied to solve the standard 30-bus IEEE system with 6 generators to validate its robustness and efficiency to produce a well-distributed Pareto frontier for constrained combined economic emission dispatch problem. Compared with other studies, good results in solving constrained combined economic emission dispatch problem are obtained and a reasonable reduced Pareto set is found. (shrink)

This volume contains a selection of Professor Uzawa's important contributions to mathematical economics. Subjects covered by these nineteen essays include consumption, production, equilibrium, capital, growth, planning, international trade, and the theory of social overhead capital. Written in the 1960s and early 1970s, the papers form a basis upon which economic theory has developed over the last twenty years. The collection includes some of Uzawa's classic contributions, such as 'Preference and Rational Choice in the Theory of Consumption', 'Time Preference, (...) the Consumption Function, and Optimum Asset Holdings', 'Neutral Inventions and the Stability of Growth Equilibrium', 'On a Two-Sector Model of Economic Growth', 'Time Preference and the Penrose Effect in a Two-Class Model of Economic Growth', and 'On the Economics of Social Overhead Capital'. The collection will be useful not only in understanding the nature of the development in economic theory today, but also in reflecting upon the direction toward which economic theory will be advancing in the future. (shrink)

Human adaptive behavior in sensorimotor control is aimed to increase the confidence in feedforward mechanisms when sensory afferents are uncertain. It is thought that these feedforward mechanisms rely on predictions from internal models. We investigate whether the brain uses an internal model of physical laws to help estimate body equilibrium when tactile inputs from the foot sole are depressed by carrying extra weight. As direct experimental evidence for such a model is limited, we used Judoka athletes thought to have (...) built up internal models of external loads as compared with Non-Athlete participants and Dancers. Using electroencephalography, we first tested the hypothesis that the influence of tactile inputs was amplified by descending cortical efferent signals. We compared the amplitude of P1N1 somatosensory cortical potential evoked by electrical stimulation of the foot sole in participants standing still with their eyes closed. We showed smaller P1N1 amplitudes in the Load compared to No Load conditions in both Non-Athletes and Dancers. This decrease neural response to tactile stimulation was associated with greater postural oscillations. By contrast in the Judoka’s group, the neural early response to tactile stimulation was unregulated in the Load condition. This suggests that the brain can selectively increase the functional gain of sensory inputs, during challenging equilibrium tasks when tactile inputs were mechanically depressed by wearing a weighted vest. In Judokas, the activation of regions such as the right posterior inferior parietal cortex as early as the P1N1 is likely the source of the neural responses being maintained similar in both Load and No Load conditions. An overweight internal model stored in the right PPC known to be involved in maintaining a coherent representation of one’s body in space can optimize predictive mechanisms in situations with high balance constraints. This hypothesis has been confirmed by showing that postural reaction evoked by a translation of the support surface on which participants were standing wearing extra-weight was improved in Judokas. (shrink)

The “welcome return” to “substantive political philosophy” that Rawls'sA Theory of Justicewas said to herald has resulted in forty years of proposals seeking to show that philosophical reflection leads to the demonstrable truth of almost every and any conceivable view of the justice of property rights. Select any view—from the justice of unregulated capitalist markets to the most extreme forms of egalitarianism—and one will find that some philosophers have proclaimed that rational reflection uniquely leads to its justice. This is, I (...) believe, a sort of ideological thinking masquerading as philosophizing. In this paper, using some tools from game theory as well as experimental findings, I seek to sketch a non-ideological approach to the question of the justification of property rights. On this approach the aim of political philosophy is, first and foremost, to reflect on whether our social rules of property are within the “optimal eligible set” of rules acceptable to all. (shrink)

Christie, Brusse, et al. claim that the ‘selected effect’ (SE) theory of function is premised on a simplistic view of evolution. In complex evolutionary scenarios, in particular those involving frequency-dependent selection (FDS), the SE theory fails, they argue, since citing a trait’s SE function does not serve to explain why the trait exists. I argue that where FDS leads to a stable equilibrium, at which all individuals’ trait values constitute a ‘best response’ to the rest of the population, (...) the SE theory can be straightforwardly applied. However, matters are different if the evolutionary dynamics do not take the population to a stable equilibrium. (shrink)

The application of phylogenetic methods to cultural variation raises questions about how cultural adaption works and how it is coupled to cultural transmission. Cultural group selection is of particular interest in this context because it depends on the same kinds of mechanisms that lead to tree-like patterns of cultural variation. Here, we review ideas about cultural group selection relevant to cultural phylogenetics. We discuss why group selection among multiple equilibria is not subject to the usual criticisms directed (...) at group selection, why multiple equilibria are a common phenomena, and why selection among multiple equilibria is not likely to be an important force in genetic evolution. We also discuss three forms of group competition and the processes that cause populations to shift from one equilibrium to another and create a mutation-like process at the group level. (shrink)

For principled and substantially philosophical reasons, based largely on his reform of natural history by inverting the Paleyan notion of overarching and purposeful beneficence in the construction of organisms, Darwin built his theory of selection at the single causal level of individual bodies engaged in unconscious struggle for their own reproductive success. But the central logic of the theory allows selection to work effectively on entities at several levels of a genealogical hierarchy, provided that they embody a set (...) of requisite features for defining evolutionary individuality. Genes, cell lineages, demes, species, and clades-as well as Darwin’s favoured organisms-embody these requisite features in enough cases to form important levels of selection in the history of life. R. A. Fisher explicitly recognized the unassailable logic of species selection, but denied that thsi real process could be important in evolution because, compared with the production of new organisms within a species, the origin of new species is so rare, and the number of species within most clades so low. I review this and other classical arguments against higher-level selection, and conclude that they are invalid in practice for interdemic selection, and false in principle for species selection. Punctuated equilibrium defines the individuality of species and refutes Fisher’s classical argument based on cycle time. In the second part of the paper, I argue that we have failed to appreciate the range and power of selection at levels above and below the organismic because we falsely extrapolate the defining properties of organisms to these other levels, and then regard the other levels as impotent because their effective individuals differ so much from organisms. We would better appreciate the power and generality of hierarchical models of selection if we grasped two key principles: first, that levels can interact in all modes, and not only in the negative style that, for heuristic and operational reasons, has received almost exclusive attention in the existing literature; and second, that each hierarchical level differs from all others in substantial and interesting ways, both in the style and frequency of patterns in change and causal modes. (shrink)

In The Structure of Biological Science I argued that the theory of natural selection is a statistical theory for reasons much like those which makes thermodynamics a statistical theory. In particular, the theory claims that fitness differences are large enough and the life span of species long enough for increases in average fitness always to appear in the long run; and this claim, I held, is of the same form as the statistical version of the second law of thermodynamics.For (...) the latter law also makes a claim about the long run, and its statistical character is due to this claim: thermodynamic systems must in the long run approach an equilibrium level of organization that maximizes entropy. Over finite times, given local boundary conditions, an isolated mechanical system, like the molecules in a container of gas, may sometimes interact so as to move the entropy of the system further from, instead of closer to the equilbrium level. But given enough interacting bodies, and enough time, the system will always eventually move in the direction prescribed by the law. Thus, we can attach much higher probabilities to the prediction that non-equilibrium systems will reflect greater entropy in future periods than we can to predictions that they will move in the opposite direction. And as we increase the amount of time and the number of bodies interacting, the strength of the probability we can attach to the prediction becomes greater and greater. (shrink)

Rebate has long been a crucial tool that has attracted researchers from a diverse range of fields including marketing and supply chain management. When a manufacturer uses a retailer for reaching end customers, the rebate strategy undertakes an additional dimension. Here we show whether the two rebate strategies, manufacturer rebate and channel rebate, can be the optimal choice for the manufacturer and the retailer. And we aim at full coordination with rebate. Game theory is exploited to identify the equilibrium (...) rebate decisions, which are fully characterized with two rebate strategies considering rebate sensitivity. Furthermore, we demonstrate how the decisions depend on parameters, such as market size, rebate redemption rate, and competition intensity in monopoly and duopoly supply chain systems. Our work also coordinates the supply chain with two coordination policies and examines if they can achieve full coordination. Counterintuitive findings suggest that the channel rebate with sensitivity and discrimination is not effective and the manufacturer rebate is the unique optimal option. Besides, the coordination can be realized with a centralized rebate in monopoly setting when the manufacturer forgoes her own interest. Then full coordination can be achieved in duopoly setting with a new coordination policy, rebate combination, given the redemption rate for the channel rebate is lower compared with the manufacturer rebate. Managerial insights are suggested that offering rebates with discrimination can have significant inventory and coordination policy implications and can lead to a double win under a well-controlled redemption rate. (shrink)

A growing number of researchers suggest that female homosexuality is at least in part influenced by genetic factors. Unlike for male homosexuality, few familial studies have attempted to explore maintenance of this apparently fitness-detrimental trait in the population. Using multiple recruitment methods, we explored fecundity and sexual orientation within the pedigrees of 1,458 adult female respondents. We compared 487 homosexual and 163 bisexual with 808 heterosexual females and 30,203 of their relatives. Our data suggest that the direct fitness of homosexual (...) females is four times lower than the direct fitness of heterosexual females of corresponding ages. The prevalence of nonheterosexuality within the homosexual female respondents’ families appear to be more than four times higher than the basal prevalence in the Italian population. Pedigree size and relative fecundity in both the paternal and maternal sides of the homosexual women’s families were significantly higher than in the heterosexuals’ families. If confirmed, the relative average fecundity increase within the family seems to offset the loss in fitness due to the low direct fitness of homosexual females. Therefore, the balanced fecundity in the homosexual females’ families may allow the trait to be maintained at a low-frequency equilibrium in the population. (shrink)

Genic selectionists (Williams 1966; Dawkins 1976) defend the view that genes are the (unique) units of selection and that all evolutionary events can be adequately represented at the genic level. Pluralistic genic selectionists (Sterelny and Kitcher 1988; Waters 1991; Dawkins 1982) defend the weaker view that in many cases there are multiple equally adequate accounts of evolutionary events, but that always among the set of equally adequate representations will be one at the genic level. We describe a range of (...) cases all involving stable equilibria actively maintained by selection. In these cases genotypic models correctly show that selection is active at the equilibrium point. In contrast, the genic models have selection disappearing at equilibrium. For deterministic models this difference makes no difference. However, once drift is added in, the two sets of models diverge in their predicted evolutionary trajectories. Thus, contrary to received wisdom on this matter, the two sets of models are not empirically equivalent. Moreover, the genic models get the facts wrong. (shrink)

A novel thermodynamic perspective on natural selection is presented. In the case that life continuity is optimized in an ideal system, where relatively constant and homogeneous selective pressures favour a given competing species, natural selection leads that system to a stationary state of maximum genotypic uniformity of life and maximum sustainable consumption of available energy by life (competitive equilibrium). Structurally and functionally, this optimizing tendency towards competitive equilibrium looks similar to the optimizing tendency towards thermodynamic (...) class='Hi'>equilibrium of classical thermodynamics (maximum energetic uniformity and maximum degradation of available energy). The principle of competitive exclusion may thus be conceptually viewed as an ecological manifestation of the second law of (classical) thermodynamics. On the other hand, the novel thermodynamic perspective on natural selection is discussed with regard to the open and nonequilibrium system of nature, where selective pressures vary in space and time. In this case, natural selection can induce diversity instead of uniformity, though an optimizing tendendcy towards maximum sustainable consumption of resources (optimization of life continuity) always remains. Overall, it is concluded that the action of natural selection favours the maximization of the sustainable consumption of energy at the level of individual organism. (shrink)

Rediscoveries are not rare in biology. A recent example is the re-birth of the "fluctuation fit" concept developed by F. B. Straub and G. Szabolcsi in the sixties of the last century, under various names, the most popular of which is the "conformational selection". This theory offers an alternative to the "induced fit" concept by Koshland for the interpretation of the mechanism of protein—ligand interactions. A central question is whether the ligand induces a conformational change (as described by the (...) induced fit model) or rather selects and stabilizes a complementary conformation from a pre-existing equilibrium of various states of the protein (according to the fluctuation fit/conformational selection model). Straub and Szabolcsi’s role and the factors hindering the spread of the fluctuation fit theory are discussed in the context of the history of the Hungarian biology in the 1950s and 1960s. (shrink)

We calculate the Lebesgue–measures of the stability sets of Nash-equilibria in pure coordination games. The results allow us to observe that the ordering induced by the Lebesgue–measure of stability sets upon strict Nash-equilibria does not necessarily agree with the ordering induced by risk–dominance. Accordingly, an equilibrium selection theory based on the Lebesgue–measure of stability sets would be necessarily different from one which uses the Nash-property as a point of orientation.

The results of two recent articles expanding the Gibbs variational principle to encompass all of statistical mechanics, in which the role of external sources is made explicit, are utilized to further explicate the theory. Representative applications to nonequilibrium thermodynamics and hydrodynamics are presented, describing several fundamental processes, including hydrodynamic fluctuations. A coherent description of macroscopic relaxation dynamics is provided, along with an exemplary demonstration of the approach to equilibrium in a simple fluid.

This book presents a historical and scientific analysis as historical epistemology of the science of weights and mechanics in the sixteenth century, particularly as developed by Tartaglia in his Quesiti et inventioni diverse, Book VII and Book VIII (1546; 1554). -/- In the early 16th century mechanics was concerned mainly with what is now called statics and was referred to as the Scientia de ponderibus, generally pursued by two very different approaches. The first was usually referred to as Aristotelian, where (...) the equilibrium of bodies was set as a balance of opposite tendencies to motion. The second, usually referred to as Archimedean, identified statics with centrobarica, the theory of centres of gravity based on symmetry considerations. In between the two traditions the Italian scholar Niccolò Fontana, better known as Tartaglia (1500?–1557), wrote the treatise Quesiti et inventioni diverse (1546). -/- This volume consists of three main parts. In the first, a historical excursus regarding Tartaglia’s lifetime, his scientific production and the Scientia de ponderibus in the Arabic-Islamic culture, and from the Middle Ages to the Renaissance, is presented. Secondly, all the propositions of Books VII and VIII, by relating them with the Problemata mechanica by the Aristotelian school and Iordani opvsculvm de ponderositate by Jordanus de Nemore are examined within the history and historical epistemology of science. The last part is relative to the original texts and critical transcriptions into Italian and Latin and an English translation. -/- This work gathers and re-evaluates the current thinking on this subject. It brings together contributions from two distinguished experts in the history and historical epistemology of science, within the fields of physics, mathematics and engineering. It also gives much-needed insight into the subject from historical and scientific points of view. The volume composition makes for absorbing reading for historians, epistemologists, philosophers and scientists. (shrink)

This paper uses a 4 × 4 expansion of the Hawk–Dove Game to illustrate how sexual drift in a large genotype space can shift a population from one equilibrium in a smaller phenotype space to another. An equilibrium is only safe from being destabilized in this way when implemented by recessive alleles.

This book presents a historical and scientific analysis as historical epistemology of the science of weights and mechanics in the sixteenth century, particularly as developed by Tartaglia in his Quesiti et inventioni diverse, Book VII and Book VIII (1546; 1554). In the early 16th century mechanics was concerned mainly with what is now called statics and was referred to as the Scientia de ponderibus, generally pursued by two very different approaches. The first was usually referred to as Aristotelian, where the (...) equilibrium of bodies was set as a balance of opposite tendencies to motion. The second, usually referred to as Archimedean, identified statics with centrobarica, the theory of centres of gravity based on symmetry considerations. In between the two traditions the Italian scholar Niccolò Fontana, better known as Tartaglia (1500?-1557), wrote the treatise Quesiti et inventioni diverse (1546). This volume consists of three main parts. In the first, a historical excursus regarding Tartaglia's lifetime, his scientific production and the Scientia de ponderibus in the Arabic-Islamic culture, and from the Middle Ages to the Renaissance, is presented. Secondly, all the propositions of Books VII and VIII, by relating them with the Problemata mechanica by the Aristotelian school and Iordani opvsculvm de ponderositate by Jordanus de Nemore are examined within the history and historical epistemology of science. The last part is relative to the original texts and critical transcriptions into Italian and Latin and an English translation. This work gathers and re-evaluates the current thinking on this subject. It brings together contributions from two distinguished experts in the history and historical epistemology of science, within the fields of physics, mathematics and engineering. It also gives much-needed insight into the subject from historical and scientific points of view. The volume composition makes for absorbing reading for historians, epistemologists, philosophers and scientists. (shrink)