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)

We study the equilibrium behavior of informed traders interacting with market scoring rule (MSR) market makers. One attractive feature of MSR is that it is myopically incentive compatible: it is optimal for traders to report their true beliefs about the likelihood of an event outcome provided that they ignore the impact of their reports on the profit they might garner from future trades. In this paper, we analyze non-myopic strategies and examine what information structures lead to truthful betting by (...) traders. Specifically, we analyze the behavior of risk-neutral traders with incomplete information playing in a dynamic game. We consider finite-stage and infinite-stage game models. For each model, we study the logarithmic market scoring rule (LMSR) with two different information structures: conditionally independent signals and (unconditionally) independent signals. In the finite-stage model, when signals of traders are independent conditional on the state of the world, truthful betting is a Perfect Bayesian Equilibrium (PBE). Moreover, it is the unique Weak Perfect Bayesian Equilibrium (WPBE) of the game. In contrast, when signals of traders are unconditionally independent, truthful betting is not a WPBE. In the infinite-stage model with unconditionally independent signals, there does not exist an equilibrium in which all information is revealed in a finite amount of time. We propose a simple discounted market scoring rule that reduces the opportunity for bluffing strategies. We show that in any WPBE for.. (shrink)

This paper develops an incomplete information model of extended deterrence relationships. It postulates players who are fully informed about the costs of war and all other relevant variables, save for the values their opponents place on the issues at stake, i.e., the pawn. We provide consistent and intuitively satisfying parallel definitions for two types of players, Hard and Soft, in terms of the parameters of our model. We also answer several particular questions about the strategy choices of players in an (...) extended deterrence relationship and, by identifying all the Perfect Bayesian Equilibria of the game model we construct, specify typical behavior patterns.Our most general finding is that an Extended Deterrence Game always has a unique Perfect Bayesian Equilibrium with a rather simple form. A challenger initiates for certain if the pawn is valuable enough to it and never challenges otherwise, Likewise, a defender always resists if the pawn is valuable enough and never resists otherwise. (shrink)

Within the context of extensive-form (or dynamic) games, we use choice frames to represent the initial beliefs of a player as well as her disposition to change those beliefs when she learns that an information set of hers has been reached. As shown in [5], in order for the revision operation to be consistent with the AGM postulates [1], the player’s choice frame must be rationalizable in terms of a total pre-order on the set of histories. We consider four properties (...) of choice frames and show that, together with the hypothesis of a common prior, are necessary and sufficient for the existence of a plausibility order that rationalizes the epistemic state (that is, initial beliefs and disposition to revise those beliefs) of all the players. The plausibility order satisfies the properties introduced in [6] as part of a new definition of perfect Bayesian equilibrium for dynamic games. Thus the present paper provides epistemic foundations for that solution concept. (shrink)

We propose a theoretical model to explain the usage of time-inconsistent behavior as a strategy to exploit others when reputation and trust have secondary effects on the economic outcome. We consider two agents with time-consistent preferences exploiting common resources. Supposing that an agent is believed to have time-inconsistent preferences with probability p, we analyze whether she uses this misinformation when she has the opportunity to use it. Using the model originally provided by Levhari and Mirman (Bell J Econ 11(1):322–334, 1980), (...) we determine the optimal degree of present bias that the agent would like to have while pretending to have time-inconsistent preferences and we provide the range of present-bias parameter under which deceiving is optimal. Moreover, by allowing the constant relative risk aversion class of utility form, we characterize the distinction between pretending to be naive and sophisticated. (shrink)

This is a two-volume set that provides an introduction to non-cooperative Game Theory. Volume 1 covers the basic concepts, while Volume 2 is devoted to advanced topics. The book is richly illustrated with approximately 400 figures. It is suitable for both self-study and as the basis for an undergraduate course in game theory as well as a first-year graduate-level class. It is written to be accessible to anybody with high-school level knowledge of mathematics. At the end of each chapter there (...) is a collection of exercises accompanied by detailed answers. The book contains approximately 180 exercises. (shrink)

In a pair of controversy provoking papers1, Kadane and Larkey argued that the normative or prescriptive understanding of expected utility theory recommended that participants in a game maximize expected utility given their assessments of the probabilities of the moves that other players would make. They observed that no prescription, norm or standard of Bayesian rationality recommends how they should come to make probability judgments about the choices of other players. For any given player, it is an empirical question as (...) to whether other players are Bayes rational, judge him to be Bayes rational, etc., just as it is an empirical question as to what the other players’ goals and beliefs are. Participants in the game should, of course, use all empirical information available to them about how other players have behaved and how they are likely to behave in the given context of choice. Kadane and Larkey pointed out that rational players could participate in a game meeting these requirements without the game’s terminating with a Nash equilibrium or a result satisfying any other particular solution concept. (shrink)

Statistical tests that detect and measure deviation from the Hardy-Weinberg equilibrium (HWE) have been devised but are limited when testing for deviation at multiallelic DNA loci is attempted. Here we present the full Bayesian significance test (FBST) for the HWE. This test depends neither on asymptotic results nor on the number of possible alleles for the particular locus being evaluated. The FBST is based on the computation of an evidence index in favor of the HWE hypothesis. A great (...) deal of forensic inference based on DNA evidence assumes that the HWE is valid for the genetic loci being used. We applied the FBST to genotypes obtained at several multiallelic short tandem repeat loci during routine parentage testing; the locus Penta E exemplifies those clearly in HWE while others such as D10S1214 and D19S253 do not appear to show this. (shrink)

Our scientific theories, like our cognitive structures in general, consist of propositions linked by evidential, explanatory, probabilistic, and logical connections. Those theoretical webs ‘impinge on the world at their edges,’ subject to a continuing barrage of incoming evidence. Our credences in the various elements of those structures change in response to that continuing barrage of evidence, as do the perceived connections between them. Here we model scientific theories as Bayesian nets, with credences at nodes and conditional links between them (...) modelled as conditional probabilities. We update those networks, in terms of both credences at nodes and conditional probabilities at links, through a temporal barrage of random incoming evidence. Robust patterns of punctuated equilibrium, suggestive of ‘normal science’ alternating with ‘paradigm shifts,’ emerge prominently in that change dynamics. The suggestion is that at least some of the phenomena at the core of the Kuhnian tradition are predictable in the typical dynamics of scientific theory change captured as Bayesian nets under even a random evidence barrage. (shrink)

How does Bayesian reasoning support participation in a game's Nash equilibrium? This paper provides an answer.

Counterexamples to two results by Stalnaker (Theory and Decision, 1994) are given and a corrected version of one of the two results is proved. Stalnaker's proposed results are: (1) if at the true state of an epistemic model of a perfect information game there is common belief in the rationality of every player and common belief that no player has false beliefs (he calls this joint condition ‘strong rationalizability’), then the true (or actual) strategy profile is path equivalent to (...) a Nash equilibrium; (2) in a normal-form game a strategy profile is strongly rationalizable if and only if it belongs to C8 , the set of profiles that survive the iterative deletion of inferior profiles. (shrink)

According to the traditional Bayesian view of credence, its structure is that of precise probability, its objects are descriptive propositions about the empirical world, and its dynamics are given by conditionalization. Each of the three essays that make up this thesis deals with a different variation on this traditional picture. The first variation replaces precise probability with sets of probabilities. The resulting imprecise Bayesianism is sometimes motivated on the grounds that our beliefs should not be more precise than the (...) evidence calls for. One known problem for this evidentially motivated imprecise view is that in certain cases, our imprecise credence in a particular proposition will remain the same no matter how much evidence we receive. In the first essay I argue that the problem is much more general than has been appreciated so far, and that it’s difficult to avoid without compromising the initial evidentialist motivation. The second variation replaces descriptive claims with moral claims as the objects of credence. I consider three standard arguments for probabilism with respect to descriptive uncertainty—representation theorem arguments, Dutch book arguments, and accuracy arguments—in order to examine whether such arguments can also be used to establish probabilism with respect to moral uncertainty. In the second essay, I argue that by and large they can, with some caveats. First, I don’t examine whether these arguments can be given sound non-cognitivist readings, and any conclusions therefore only hold conditional on cognitivism. Second, decision-theoretic representation theorems are found to be less convincing in the moral case, because there they implausibly commit us to thinking that intertheoretic comparisons of value are always possible. Third and finally, certain considerations may lead one to think that imprecise probabilism provides a more plausible model of moral epistemology. The third variation considers whether, in addition to conditionalization, agents may also change their minds by becoming aware of propositions they had not previously entertained, and therefore not previously assigned any probability. More specifically, I argue that if we wish to make room for reflective equilibrium in a probabilistic moral epistemology, we must allow for awareness growth. In the third essay, I sketch the outline of such a Bayesian account of reflective equilibrium. Given that this account gives a central place to awareness growth, and that the rationality constraints on belief change by awareness growth are much weaker than those on belief change by conditionalization, it follows that the rationality constraints on the credences of agents who are seeking reflective equilibrium are correspondingly weaker. (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.

Bayesian epistemology provides a popular and powerful framework for modeling rational norms on credences, including how rational agents should respond to evidence. The framework is built on the assumption that ideally rational agents have credences, or degrees of belief, that are representable by numbers that obey the axioms of probability. From there, further constraints are proposed regarding which credence assignments are rationally permissible, and how rational agents’ credences should change upon learning new evidence. While the details are hotly disputed, (...) all flavors of Bayesianism purport to give us norms of ideal rationality. This raises the question of how exactly these norms apply to you and me, since perfect compliance with those ideal norms is out of reach for human thinkers. A common response is that Bayesian norms are ideals that human reasoners are supposed to approximate – the closer they come to being ideally rational, the better. To make this claim plausible, we need to make it more precise. In what sense is it better to be closer to ideally rational, and what is an appropriate measure of such closeness? This article sketches some possible answers to these questions. (shrink)

We generalize the concept of Nash equilibrium in mixed strategies for strategic form games to allow for ambiguity in the players' expectations. In contrast to other contributions, we model ambiguity by means of so-called lower probability measures or belief functions, which makes it possible to distinguish between a player's assessment of ambiguity and his attitude towards ambiguity. We also generalize the concept of trembling hand perfect equilibrium. Finally, we demonstrate that for certain attitudes towards ambiguity it is (...) possible to explain cooperation in the one-shot Prisoner's Dilemma in a way that is in accordance with some recent experimental findings. (shrink)

Bayesianism is the predominant philosophy of science in North-America, the most important school of statistics world-wide, and the general version of the rational-choice approach in the social sciences. Although often rejected as a theory of actual behavior, it is still the benchmark case of perfect rationality. The paper reviews the development of Bayesianism in philosophy, statistics and decision making and questions its status as an account of perfect rationality. Bayesians, who otherwise are squarely in the empiricist camp, invoke (...) a priori reasoning when they recommend Bayesian methods - a recommendation that is not justified by their own standards. (shrink)

Bayesian approaches to rationality require that a person’s degrees of belief be coherent. Among other implications, coherence requires that a person has the same degree of belief in every logically equivalent proposition. However, a person can have evidence for a claim without having evidence for all its propositional equivalences. This paper explores this conflict and argues that a person may be perfectly rational by virtue of responding to their evidence, even if their credences are not coherent. The paper also (...) challenges the idea that it is always better to have more coherent credence, highlighting the fundamental role that evidence plays in rational belief. (shrink)

Game-theoretic reasoning pervades economic theory and is used widely in other social and behavioural sciences. An Introduction to Game Theory International Edition, by Martin J. Osborne, presents the main principles of game theory and shows how they can be used to understand economics, social, political, and biological phenomena. The book introduces in an accessible manner the main ideas behind the theory rather than their mathematical expression. All concepts are defined precisely, and logical reasoning is used throughout. The book requires an (...) understanding of basic mathematics but assumes no specific knowledge of economics, political science, or other social or behavioural sciences. Coverage includes the fundamental concepts of strategic games, extensive games with perfect information, and coalitional games; the more advanced subjects of Bayesian games and extensive games with imperfect information; and the topics of repeated games, bargaining theory, evolutionary equilibrium, rationalizability, and maxminimization. The book offers a wide variety of illustrations from the social and behavioural sciences. Each topic features examples that highlight theoretical points and illustrations that demonstrate how the theory may be used. (shrink)

The theory of rational decision has always been implicitly involved with subjunctive and counterfactual conditionals. “If I were to do A, this would happen; if I were to do B that would happen. ” When I have done A, I use the counterfactual: “If I had done B, the outcome would have been worse. ” Counterfactuals are handled so smoothly in decision theory and game theory that they are hardly ever explicitly discussed except in cases where they cause problems. For (...) many philosophers, Newcomb’s paradox was such a critical case ). In game theory, questions about beliefs off the equilibrium path in extensive form games and related issues of backward and forward induction provoked explicit discussion of counterfactuals , Bicchieri , Binmore , Harsanyi and Selten , Reny , Stalnaker , ). Where subjunctive conditionals cause problems, we need an explicit theory. What theory should we use? There is the selection function semantics of Stalnaker based on the idea of “most similar possible world in which the antecedent is true”, and related theories of Woodruff , Lewis , Pollock , Nute , which relax some of Stalnaker’s assumptions. (shrink)

Perfect adaptation in a dynamical system is the phenomenon that one or more variables have an initial transient response to a persistent change in an external stimulus but revert to their original value as the system converges to equilibrium. With the help of the causal ordering algorithm, one can construct graphical representations of dynamical systems that represent the causal relations between the variables and the conditional independences in the equilibrium distribution. We apply these tools to formulate sufficient (...) graphical conditions for identifying perfect adaptation from a set of first-order differential equations. Furthermore, we give sufficient conditions to test for the presence of perfect adaptation in experimental equilibrium data. We apply this method to a simple model for a protein signalling pathway and test its predictions in both simulations and using real-world protein expression data. We demonstrate that perfect adaptation can lead to misleading orientation of edges in the output of causal discovery algorithms. (shrink)

In a Bayesian dialogue two individuals report their Bayesian updated belief about a certain event back and forth, at each step taking into account the additional information contained in the updated belief announced by the other at the previous step. Such a process, which operates through a reduction of the set of possible states of the world, converges to a commonly known posterior belief, which can be interpreted as a dynamic foundation for Aumann’s agreement result. Certainly, if two (...) individuals have diverging interests, truthfully reporting one’s Bayesian updated belief at every step might not be optimal. This observation could lead to the intuition that always truthfully reporting one’s Bayesian updated belief were the best that two individuals could do if they had perfectly coinciding interests and these were in line with coming to know the truth. This article provides an example which shows this intuition to be wrong. In this example, at some step of the process, one individual has an incentive to deviate from truthfully reporting his Bayesian updated belief. However, not in order to hide the truth, but to help it come out at the end: to prevent the process from settling into a commonly known belief—the “Aumann conditions”—on a certain subset of the set of possible states of the world, and this way make it converge to a subset of the set of possible states of the world on which it will be commonly known whether the event in question has occurred or not. The strategic movement described in this example is similar to a conversational implicature: the correct interpretation of the deviation from truthfully reporting the Bayesian updated belief thrives on it being common knowledge that the announced probability cannot possibly be the speaker’s Bayesian updated belief at this step. Finally, the argument is embedded in a game-theoretic model. (shrink)

One of the problems that Bayesian regularity, the thesis that all contingent propositions should be given probabilities strictly between zero and one, faces is the possibility of random processes that randomly and uniformly choose a number between zero and one. According to classical probability theory, the probability that such a process picks a particular number in the range is zero, but of course any number in the range can indeed be picked. There is a solution to this particular problem (...) on the books: a measure that assigns the same infinitesimal probability to each number between zero and one. I will show that such a measure, while mathematically interesting, is pathological for use in confirmation theory, for the same reason that a measure that assigns an infinitesimal probability to each possible outcome in a countably infinite lottery is pathological. The pathology is that one can force someone to assign a probability within an infinitesimal of one to an unlikely event. (shrink)

In political economy, the seminal contribution of the Baron–Ferejohn bargaining model constitutes an important milestone for the study of legislative policy making. In this paper, we analyze a particular equilibrium characteristic of this model, equilibrium uniqueness. The Baron–Ferejohn model yields a class of payoff-unique stationary subgame perfect equilibria in which players’ equilibrium strategies are not uniquely determined. We first provide a formal proof of the multiplicity of equilibrium strategies. This also enables us to establish some (...) important properties of SSPE. We then introduce veto players into the original Baron–Ferejohn model. We state the conditions under which the new model has a unique SSPE not only in terms of payoffs but also in terms of players’ equilibrium strategies. (shrink)

The theory of competition has held a central place in economic analysis since Adam Smith. This book, written by one of the most distinguished of contemporary economic theorists, reports on a major research program to provide strategic foundations for the theory of perfect competition. Beginning with a concise survey of how the theory of competition has evolved, Gale makes extensive and rigorous use of dynamic matching and bargaining models to provide a more complete description of how a competitive equlibrium (...) is achieved. Whereas economists have made use of a macroscopic description of markets in which certain behavioral characteristics, such as price-taking behavior, are taken for granted, Gale uses game theory to re-evaluate this assumption, beginning with individual agents and modelling their strategic interaction. A strategic foundation for competitive equilibrium shows how such interaction leads to competitive, price-taking behavior. Essential reading for graduate courses in game theory and general equilibrium. (shrink)

Much forensic inference based upon DNA evidence is made assuming Hardy-Weinberg Equilibrium (HWE) for the genetic loci being used. Several statistical tests to detect and measure deviation from HWE have been devised, and their limitations become more obvious when testing for deviation within multiallelic DNA loci. The most popular methods-Chi-square and Likelihood-ratio tests-are based on asymptotic results and cannot guarantee a good performance in the presence of low frequency genotypes. Since the parameter space dimension increases at a quadratic rate (...) on the number of alleles, some authors suggest applying sequential methods, where the multiallelic case is reformulated as a sequence of “biallelic” tests. However, in this approach it is not obvious how to assess the general evidence of the original hypothesis; nor is it clear how to establish the significance level for its acceptance/rejection. In this work, we introduce a straightforward method for the multiallelic HWE test, which overcomes the aforementioned issues of sequential methods. The core theory for the proposed method is given by the Full Bayesian Significance Test (FBST), an intuitive Bayesian approach which does not assign positive probabilities to zero measure sets when testing sharp hypotheses. We compare FBST performance to Chi-square, Likelihood-ratio and Markov chain tests, in three numerical experiments. The results suggest that FBST is a robust and high performance method for the HWE test, even in the presence of several alleles and small sample sizes. (shrink)

The purpose of this paper aims to unravel the ideological strategy that rises from the well-celebrated epistemic rigor of neoclassical economic thought. From the Economics Nobel Price Paul Krugman’s popularized connotation naming to "freshwater" economists as those fervent followers of the most orthodox academic creed, we will expose the logical inconsistency and empirical implausibility of such thought’s underlying assumptions: perfect competence and equilibrium’s approaching. From a critical analysis that will be conducted from each of those mentioned assumptions, we (...) will argued that the neoclassical thought is an ideological strategy subverting reality’s principles, overcoming "artificially" those relevant deficiencies and limitations of its theoretical approach. A lo largo de este trabajo se intenta desvelar la estrategia ideológica que emana del celebrado rigorismo epistémico del pensamiento neoclásico de economía. Desde la connotación popularizada por el Nobel Paul Krugman a los economistas de "agua dulce" como aquellos fervientes seguidores del credo académico más ortodoxo, expondremos la incoherencia lógica e imposibilidad empírica de los supuestos fundamentales de su pensamiento: competencia perfecta y aproximación al equilibrio. Desde un examen crítico que irá conduciéndose por cada uno de tales supuestos, resolveremos cómo el marco neoclásico no es más que una estrategia ideológica que subvirtiendo los principios de lo real consigue superar solo "artificialmente" las importantes deficiencias y limitaciones de su marco teórico. (shrink)

Ideal agents are role models whose perfection in some normative domain we try to approximate. But which form should this striving take? It is well known that following ideal rules of practical reasoning can have disastrous results for non-ideal agents. Yet, this issue has not been explored with respect to rules of theoretical reasoning. I show how we can extend Bayesian models of ideally rational agents in order to pose and answer the question of whether non-ideal agents should form (...) new degrees of belief in the same way as their ideal counterparts. I demonstrate that the epistemic and the practical case are parallel: following ideal rules does not always lead to optimal outcomes for non-ideal agents. (shrink)

For the past 20 years or so the literature on noncooperative games has been centered on the search for an equilibrium concept that expresses the notion of rational behavior in interactive situations. A basic tenet in this literature is that if a “rational solution” exists, it must be a Nash equilibrium. The consensus view, however, is that not all Nash equilibria can be accepted as rational solutions. Consider, for example, the game of Figure 1.

The majority of studies on natural resources management in both developed and developing countries are silent on the issue of analysis of corruption – or they treat it tangentially, as an annoying anomaly, or simply deviance from the rules. As a result, the issue has hardly been subjected to in-depth characterisation or reforms. This study employed and integrated mainstream principal-agent theory and more recently developed collective action theory to enhance our understanding – in different but complementary ways − of the (...) socio-political underpinnings of corruption. A supposed ‘best case’ participatory forest management scheme in Tanzania reveals significant forest-related corrupt undertakings, which led to forest encroachment in the form of charcoal and timber exploitation. The findings point to contextual grounds for corruption, namely: undermined assumptions of the mainstream principal-agent institutions; the presence of alternative informal principal-agent institutions; the presence of immediate and substantial benefits that flow to such alternative institutions; and the huge market demands for their forest products and services. Through such a nuanced approach that blends the two above-mentioned theories in meaningful ways, more appropriate options for policy formulation and implementation are proposed. (shrink)

We live in an ageing society, where people are living longer, and where decreases in the birth rate mean that the proportion of the population above retirement age is steadily increasing. An ageing population has considerable implications for health services and care provision. Consequently there is a growing interest among researchers, medical practitioners, and policy makers in older adults, their capabilities, and the changes in their cognitive functioning. This book offers an up-to-the-minute account of the latest methodological and theoretical issues (...) in cognitive ageing. Part of the Debates in Psychology series, it sets out the arguments surrounding the currently controversial questions in cognitive ageing. What is the appropriate methodology for understanding cognitive change? How many factors are necessary to understand the patterns of age-related change? What might these factors be? The topics and arguments are explored in a series of chapters by the leading researchers in the field. Each contributor offers their view of how cognitive ageing can be best understood, and together they cover a broad range of cognitive functions including language use, cognitive slowing, and memory loss. Each of the chapters stands alone as the latest review of work in the area. Taken together, the chapters form a coherent theoretical debate through which the reader will learn about the dynamic nature of cognitive ageing research, and about the direction this research will be taking in the future. Models of Cognitive Aging will be an invaluable resource for anyone with an interest in the elderly, and in their cognitive abilities. (shrink)

We modify the payment rule of the standard divide the dollar (DD) game by introducing a second stage and thereby resolve the multiplicity problem and implement equal division of the dollar in equilibrium. In the standard DD game, if the sum of players’ demands is less than or equal to a dollar, each player receives what he demanded; if the sum of demands is greater than a dollar, all players receive zero. We modify this second part, which involves a (...) harsh punishment. In the modified game $(D\!D^{\prime })$ , if the demands are incompatible, then players have one more chance. In particular, they play an ultimatum game to avoid the excess. In the two-player version of this game, there is a unique subgame perfect Nash equilibrium in which players demand (and receive) an equal share of the dollar. We also provide an $n$ -player extension of our mechanism. Finally, the mechanism we propose eliminates not only all pure strategy equilibria involving unequal divisions of the dollar, but also all equilibria where players mix over different demands in the first stage. (shrink)

As the first full-length book dedicated to the philosophical legacy of Hans Jonas, The Integrity of Thinking is largely dedicated to summarizing and integrating the diverse phases in Jonas’ lifework. But the book has another, more ambitious goal. David Levy attempts to demonstrate that Hans Jonas is, for matters of public policy, nothing less than the most important philosopher of the twentieth century. This alleged importance stems from his unique philosophical achievements and their manifold practical applications. According to Levy, Jonas’ (...) massive future importance will not be constrained to philosophy. Levy makes a series of admittedly “bold claims” regarding Jonas’ significance, culminating in the claim that he is “perhaps the pre-eminent practical thinker of our time”. This is excessive praise for a thinker who is still a relatively minor figure in twentieth-century philosophy, and who is still somewhat unknown by non-specialists outside his native Germany. Yet Levy hopes that the heightened public awareness of tensions between technology and ethics will create an audience for the thinker who has most successfully probed the origins of those tensions. Levy wishes to disseminate Jonas’ practical importance to a wider audience. But does Jonas merit these excessive claims, and therefore a wider audience? (shrink)

As the first full-length book dedicated to the philosophical legacy of Hans Jonas, The Integrity of Thinking is largely dedicated to summarizing and integrating the diverse phases in Jonas’ lifework. But the book has another, more ambitious goal. David Levy attempts to demonstrate that Hans Jonas is, for matters of public policy, nothing less than the most important philosopher of the twentieth century. This alleged importance stems from his unique philosophical achievements and their manifold practical applications. According to Levy, Jonas’ (...) massive future importance will not be constrained to philosophy. Levy makes a series of admittedly “bold claims” regarding Jonas’ significance, culminating in the claim that he is “perhaps the pre-eminent practical thinker of our time”. This is excessive praise for a thinker who is still a relatively minor figure in twentieth-century philosophy, and who is still somewhat unknown by non-specialists outside his native Germany. Yet Levy hopes that the heightened public awareness of tensions between technology and ethics will create an audience for the thinker who has most successfully probed the origins of those tensions. Levy wishes to disseminate Jonas’ practical importance to a wider audience. But does Jonas merit these excessive claims, and therefore a wider audience? (shrink)

"De interpretatione" from Aristoteles. Aristotle (384-322 BCE) was a Greek philosopher born in Greece.

It is sometimes the case that one solution concept in game theory is equivalent to applying another solution concept to a modified version of the game. In such cases, does it make sense to study the former separately, or should we entirely subordinate it to the latter? The answer probably depends on the particular circumstances, and indeed the literature takes different approaches in different cases. In this article, I consider the specific example of Stackelberg mixed strategies. I argue that, even (...) though a Stackelberg mixed strategy can also be seen as a subgame perfect Nash equilibrium of a corresponding extensive-form game, there remains significant value in studying it separately. The analysis of this special case may have implications for other solution concepts. (shrink)

"De unitate intellectus contra Averroistas" from Thomas Aquinas. Thomas Aquinas (1225-1274), sanctus, doctor Ecclesiae catholicae, theologus italianus et philosophus mediaevalis.

This article examines two cases that present ethical challenges encountered by social workers in making decisions either to maintain professional boundaries or fulfil moral obligations while working with service users in vulnerable situations. In the first case, a Lebanese social worker narrates how she was motivated to step out of her official responsibilities to assist a refugee mother of three who showed suicidal ideation. In the second case, a Ugandan social worker recounts her experience while working with a family whose (...) 12-year-old daughter was raped and became pregnant, but whose parents refused to accept abortion when medical diagnosis showed that the girl’s life was in danger. A commentary from the authors is provided after each case. Both social workers were arguably motivated to act based on their concern to care for people, protect human rights, and save lives in the two case scenarios. This underscores the relevance of the ethics of care and virtue ethics in describing the associated ethical challenges in both cases. Furthermore, the dynamic nature of the ethical challenges encountered by the social workers demands open minds and flexibility in decision-making. (shrink)