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Accueil > Séminaires réguliers > Séminaires Caen > Archives

2011-2012

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Les séminaires du CREM à Caen ont lieu salle EG107

de l’UFR Sciences Economiques et de Gestion de Caen, 19 rue Claude Bloch, le lundi à partir de 14h15

 


  • lundi 11 juin 2012 , 14h15 à 15h45
Intervenant Issofa Moyouwou , École Normale Supérieure, Yaounde (Cameroun)
Invité par / invited by Boniface Mbih
Thème / Subject Choix social, Jeux coopératifs
Titre / title Manipulation and Positive Externalities : The Case of Three-Party Elections
Co-auteurs/Joint work with Nicolas Gabriel Andjiga and Roland Pongou
Résumé / abstract That an elector can sometimes secure a more favorable election outcome by not voting according to his true preferences is seen as a major defect of most democratic voting systems. It is claimed that insincere voting deprives a society from its best policy. However, this claim has not been investigated. We take up this challenge, and looking beyond the indecency of preference misrepresentation, we ask whether good can come out of evil : can a pivotal insincere vote have positive externalities on sincere electors in the sense of inducing a voting outcome that they prefer to the « honest » outcome ? We answer this question in the case of large three-party elections held under (1,λ,0)-rules, rules that give a party 1 point if ranked first by an elector, λ (0≤λ≤1) point if ranked second, and 0 points if ranked third, and declare as winner the party with the most points.

  • lundi 4 juin 2012 , 14h15 à 15h45
Intervenant Anna Khmelnitskaya , Saint-Petersburg State University
Invité par / invited by Vincent Merlin
Thème / Subject Social capital, centrality, TU game, communication structure, Shapley value, Myerson value
Titre / title A social capital index
Co-auteurs/Joint work with Enrique González-Aranguena, Conrado Manuel, and Mónica del Pozo
Résumé / abstract "During last two decades the concept of social capital has been actively popularized by social scientists – economists, sociologists, political scientists. The concept of social capital initially appeared to highlight the importance of social network relations as a valuable resource for social and economic affairs. However, the current meaning of social capital is wider and nowadays it is usually assumed that social capital describes circumstances in which individuals can use membership in groups and networks to secure benefits. This formulation treats social capital as an attribute of an individual that cannot be evaluated without knowledge of the society in which the individual operates.
Our main concern is to introduce a numerical measure of individual social capital for a society composed by a finite set of individuals. We assume that interests and abilities of individuals (players) and their coalitions are represented by means of a cooperative game with transferable utility and players’ personal bilateral relations (social network) are introduced via a graph. Given a cooperative game and a communication graph we define an index of a player’s individual social capital as an excess of the Myerson value over the Shapley value of the player. The difference between Myerson and Shapley values can be naturally interpreted as a marginal contribution of the communication graph to players’ payoffs, and therefore, it provides a tool for revealing the influence of the player’s social network relations to the outcome of the game. Remark that the such defined social capital index is ideologically close to the centrality measure introduced in Gomez et al. (2003). But while in the above mentioned paper the authors define the centrality measure only for evaluation of a player’s positional importance in a graph avoiding a priori differences among players and thus using a symmetric game, we define the social capital index as an index of player’s relational importance admitting that players possibly have different cooperative abilities.
In the paper we study general properties of the social capital index and reveal its upper and lower bounds. We show that, given a game and a communication graph, the social capital of a player reaches its maximum when the communication graph is a star and the player is the hub of this star, while the social capital of a player is minimal when the player is an isolated point in a communication graph. The computations done for two real-life examples : (i) 1983 Italian Parliament elections when Bettino Craxi from the Italian Socialist Party, which got in the Lower Chamber only 73 seats from the total amount of 630 but had very strong central position, became the Prime Minister, and (ii) 2009 Basque Country Parliament elections when the Basque Nationalist Party winning the maximal number of seats finally was not included into the majority due to its weak communication ability on the political spectrum, clearly show the coincidence of our theoretical predictions with the reality.
"
Lien / download A social capital index

  • lundi 21 mai 2012 , 14h15 à 15h45
Intervenant Sebastien Bervoets ,GREQAM
Invité par / invited by Vincent Merlin
Thème / Subject Education, Réseaux
Titre / title The Role of Social Networks and Peer Effects in Education Transmission
Résumé / abstract We propose a dynastic model in which individuals are born in an educated or uneducated environment that they inherit from their parents. We study the role of social networks on the correlation in the parent-child educational status independent of any parent-child interaction. We show that the network reduces the intergenerational correlation, promotes social mobility and increases the average education level in the population. We also show that a planner that encourages social mobility also reduces social welfare, hence facing a trade off between these two objectives. When individuals choose the optimal level of social mobility, those born in an uneducated environment always want to leave their environment while the reverse occurs for individuals born in an educated environment.

  • lundi 23 avril 2012 , 14h15 à 15h45
Intervenant Rima Hawi , Paris-X Nanterre, PHARE
Invité par / invited by Muriel Gilardone
Thème / Subject John Rawls
Titre / title Les leçons des archives de Harvard
Résumé / abstract "L’analyse de John Rawls part du constat de l’inégalité des conditions sociales et de la nécessité d’articuler les champs disciplinaires pour pouvoir aborder la manière dont on peut remédier à ses différents effets : selon lui, en tant que conception, mais aussi en tant qu’enjeu de société, la justice ne peut se penser de manière exclusive. Elle tire au contraire sa richesse de l’articulation entre la philosophie, la morale, le politique et l’économique, pour ne citer que ses domaines de réflexion.
Cette contribution, en s’appuyant sur un travail de recherche mené dans les archives de Rawls à Harvard, sur une étude approfondie des annotations et index qu’il rédigeait sur chaque ouvrage parcouru, vise à montrer comment cet auteur puise de ce qui l’entoure, dans ses lectures diverses et dans son vécu, les éléments essentiels à la construction de sa théorie : la justice comme équité. Il s’agira, plus précisément, de rendre compte de la manière dont Rawls s’approprie certains concepts propres à l’analyse économique, afin de pouvoir penser les questions de justice et de démocratie.
L’analyse de John Rawls part du constat de l’inégalité des conditions sociales et de la nécessité d’articuler les champs disciplinaires pour pouvoir aborder la manière dont on peut remédier à ses différents effets : selon lui, en tant que conception, mais aussi en tant qu’enjeu de société, la justice ne peut se penser de manière exclusive. Elle tire au contraire sa richesse de l’articulation entre la philosophie, la morale, le politique et l’économique, pour ne citer que ses domaines de réflexion.
Cette contribution, en s’appuyant sur un travail de recherche mené dans les archives de Rawls à Harvard, sur une étude approfondie des annotations et index qu’il rédigeait sur chaque ouvrage parcouru, vise à montrer comment cet auteur puise de ce qui l’entoure, dans ses lectures diverses et dans son vécu, les éléments essentiels à la construction de sa théorie : la justice comme équité. Il s’agira, plus précisément, de rendre compte de la manière dont Rawls s’approprie certains concepts propres à l’analyse économique, afin de pouvoir penser les questions de justice et de démocratie."

  • lundi 16 avril 2012 , 14h15 à 15h45
Intervenant Vincent Merlin , Université Caen Basse-Normandie, CREM
Invité par / invited by Séminaire interne
Thème / Subject Vote, manipulation, fédéralisme
Titre / title Can we Avoid Vote Swapping in Representative Democracies ?
Résumé / abstract "It is a well-know fact that two tiers voting rules are subject to manipulation via gerrymandering by the election designers.
Similarly, if there are more than three candidates, voters in distinct jurisdictions may have an interest into swapping their votes in order to defeat the candidates they dislike most.
Several contributions (Chambers (2008) and Perote-Pena (2005), Bervoets and Merlin (2011)) analyzed the problem of finding the rules which would be insensitive to gerrymandering. They found that only very undemocratic rules survive, in the sense that they do not treat the different candidates equally. However, a frequent criticism comes from the fact that the size of the jurisdictions could vary heavily in the proofs. In this paper, we add the constraint that the sizes of the jurisdictions remain fixed. Only constrained gerrymandering is possible and / or vote swapping. We find that the results remain very pessimistic about the possibility of finding democratic swap-proof and constrained gerrymander-proof voting rules.
"

  • lundi 2 avril 2012 , 14h15 à 15h45
Intervenant Emeline Bezin , Université Catholique de Louvain
Invité par / invited by Frédéric Chantreuil
Thème / Subject Lien entre inégalités sociales et inégalités face à l’environnement
Titre / title The evolution of environmental concern and the dynamics of pollution
Résumé / abstract Although the evolution of environmental concern has exhibited a very similar pattern in industrialized and developing nations so that it has been widely demonstrated to be now as spread in both kind of countries, many pollutions have steadily increased within the latter group while it was stabilizing in the former one. To explain those facts, we develop a dynamic model within which the evolution of pollution and the formation of environmental concern are both endogenous. We first set up an overlapping generation model based on John and Pecchenino’s [1994] in which environmental concern, view as a perception of pollution, can vary within the population but is still fixed in time. We find that it is not always better for the long run environment to have a lot of environmentally concerned people and that this depends upon the available technology for the pollution production process. The technological factor matters because it determines the ease of reducing pollution in terms of its opportunity cost in consumption units. Hence, we show that a sufficient number of people who care about environment is needed in order to reach a stationary state as long as the available technology is clean. However if the technology is quite polluting a steady state will exist only if the share of environmentally concerned people is low enough. In a second step, we consider the composition of the population to be endogenous while environmental concern is transmitted through a socialization process based on Bisin and Verdier [1998, 2000] in which we further assume that pollution interacts. We show that as long as pollution and the culture sphere interact in a non negligible way, a stationary state characterized by a low (but nonzero) share of environmentally concerned people does not exist anymore. The existence of a stable steady state requires a clean technology for pollution production. This steady state is always characterized by an heterogeneous composition of the population where the fraction of people concerned by the environment is relatively high. Our model points out that it is not sufficient to be environmentally concerned to achieve pollution stabilization and that a clean technology for the pollution production process is also required. Furthermore when the share of environmentally concerned agents is endogenously determined, while having both previous conditions is still sufficient, it now turns to be also necessary. Actually with a polluting technology, individuals who are concerned with pollution cannot do anything but increase their consumption so that a rise of their number makes the environment more favorable to the transmission of their own trait. It supports the empirical evidences on the two different trends which have linked the environmental concern and the evolution of pollution.

  • lundi 26 mars 2012 , 14h15 à 15h45
Intervenant Philippe Poinsot , Université Paris I
Invité par / invited by Muriel Gilardone
Thème / Subject Jules Dupuit et l’exploitation des chemins de fer
Titre / title Jules Dupuit et les chemins de fer : faut-il que l’Etat intervienne ?
Résumé / abstract Au XIXe siècle émerge en France un nouveau mode de transport de voyageurs et de marchandises : les chemins de fer. Cette émergence est à l’origine de nouvelles questions analytiques puisque les chemins de fer sont, contrairement aux canaux et aux routes qui étaient les principaux modes de transport au début du XIXe siècle, des monopoles naturels. Dupuit s’exprimera à plusieurs reprises sur cette question (1853, 1861, 1862) et adopte plusieurs positions qui peuvent a priori sembler contradictoires. C’est d’ailleurs ce qui a conduit, récemment, à une controverse entre les commentateurs de Dupuit puisque, pour certains (Ekelund & Hébert, 2003, 2012), la concurrence illimitée est possible pour Dupuit, mais elle est aussi préférable aux monopoles des compagnies et à la gestion étatique, alors que pour d’autres, tels que Béraud (2005), Numa (2010) et Mosca (2008), Dupuit reconnait que les chemins de fer ont les caractéristiques des monopoles naturels – la concurrence illimitée y serait alors impossible –, de sorte qu’il conclut que l’exploitation par l’État est supérieure à celle du monopole des compagnies. Chacune de ces deux interprétations est défendable, mais toutes les deux peuvent être contredites par des affirmations de Dupuit. L’ambition de cet article est donc, sur la base d’un argument logique, de rétablir la cohérence de la position de Dupuit sur les chemins de fer et de montrer que les différentes recommandations de l’auteur correspondent à des situations différentes – existence ou non d’une concurrence intermodale, transport de voyageurs ou de marchandises… D’une part, je montrerai donc qu’il est nécessaire, pour bien comprendre les propos de Dupuit, de distinguer la question de la concurrence illimitée comme idéal de celle de la possibilité pratique de la concurrence dans l’industrie ferroviaire. La concurrence illimitée dans les chemins de fer étant impossible et pas forcément désirable pour la société, je préciserai sous quelles conditions, selon l’auteur, l’Etat doit exploiter lui-même les voies de chemins de fer plutôt que de laisser les compagnies privées en situation de monopole.

  • jeudi 22 mars 2012 9h30-11h00
Intervenant Angelo Fanelli , Nanyang Technological University, Singapour
Invité par / invited by Vincent Merlin
Thème / Subject Théorie des jeux algorithmique
Titre / title Introduction to natural Nash dynamics and equilibria computation, with application to congestion games
Co-auteurs/Joint work with Caragiannis I., Gravin N. and Skopalik A.
Résumé / abstract Congestion games constitute an important class of games in which computing an exact or even approximate pure Nash equilibrium is in general PLS-complete. We present a surprisingly simple polynomial-time algorithm that computes O(1)-approximate Nash equilibria in these games. In particular, for congestion games with linear latency functions, our algorithm computes (2+ε)-approximate pure Nash equilibria in time polynomial in the number of players, the number of resources and 1/ε. It also applies to games with polynomial latency functions with constant maximum degree d ; there, the approximation guarantee is dO(d). The algorithm essentially identifies a polynomially long sequence of best-response moves that lead to an approximate equilibrium ; the existence of such short sequences is interesting in itself. These

  • lundi 19 mars 2012 , 14h15 à 15h45
Intervenant Roy Thurik , Erasmus Rotterdam University
Invité par / invited by Patricia Renou-Maissant
Thème / Subject A new approach to understand economic and other decisions
Titre / title Geno-economics : genes and the future of researching economic behaviour
Co-auteurs/Joint work with Beauchamp, Jonathan P., David Cesarini, Magnus Johannesson, Matthijs J. H. M. van der Loos, Philipp D. Koellinger, Patrick J. F. Groenen, James H. Fowler, J. Niels Rosenquist, and Nicholas A. Christakis
Résumé / abstract Twin and adoption studies have consistently found that genetic variation is an important source of heterogeneity in economic and other outcomes. The advent of inexpensive, genome-wide scans is now making it increasingly feasible to directly examine specific genetic variants that predict individual differences. The challenges are discussed that arise when doing inference in genoeconomics research, emphasizing the importance of properly correcting for multiple hypothesis testing and of replicating significant results in independent samples. Also issues of power and sample size are dealt with. If proper attention is given to these methodological challenges, the burgeoning field of geno-economics will add a valuable new dimension to our understanding of heterogeneity in economic outcomes.
Lien / download http://dx.doi.org/10.1257/jep.25.4.57

  • lundi 12 mars 2012 , 14h15 à 15h45
Intervenant Alexandra Litsa et Jean-François Maguet, Université de Caen, CREM, UMR CNRS 6211
Invité par / invited by Séminaire interne
Thème / Subject Appariements, préférences
Titre / title The College Choice Mechanism Design
Résumé / abstract A crucial issue in the problem of school choice is that students can have a ‘degree’ of priorities when faced with the choice of schools. However, according to the existing literature, the mechanisms behind this issue consider strict preferences for students and priorities for schools. In this paper, we assume that students have also their own priorities to which is associated some ‘degree’ that designates the preference of an individual (resp. college) for a college relative to parameters that characterize the latter one (resp. individual). Thus, we talk about fuzzy priorities. Our purpose is to analyze this missing problem in the literature and to propose a mechanism which takes into account the priorities and their respective degree for both students and colleges.
Lien / download The College Choice Mechanism Design (pdf - 457 Ko)
  • lundi 5 mars 2012 , 14h15 à 15h45
Intervenant Bora Erdamar, Istanbul Bilgi University, Turquie
Invité par / invited by Maurice Salles
Thème / Subject Consensus Measures, Approval Voting, Preference-Approvals, Manipulability
Titre / title Measuring Consensus in a Preference-Approval Context
Co-auteurs/Joint work with José Luis García Lapresta, David Pérez Roman, Remzi Sanver
Résumé / abstract We consider measuring the degree of homogeneity for preference-approval profiles which include the approval information for the alternatives as well as the rankings of them. For any given set of alternatives, a preference-approval is defined by a weak ordering of the alternative set, subsets of approved and disapproved alternatives and a consistency condition. A distance-based approach is followed to measure the disagreement for any given two preference-approvals and we show that the proposed measure of consensus is robust to the extensions of the ordinal framework under the condition that a proper metric is used.
Lien / download Measuring Consensus in a Preference-Approval Context (pdf - 322 Ko)

  • lundi 20 février 2012 , 14h15 à 15h45
Intervenant Gilles Renault Université de Cergy Pontoise, THEMA
Invité par / invited by Jean Bonnet
Thème / Subject Théorie des incitations
Titre / title Push-Me Pull-You : Comparatie Advertising in the US OTC Analgesics Industry
Co-auteurs/Joint work with Simon Anderson, Federico Ciliberto and Jura Liaukonyte
Résumé / abstract We model comparative advertising as brands pushing up own brand perception and pulling down the brand image of targeted rivals. We watched all TV advertisements for OTC analgesics 2001-2005 to construct matrices of rival targeting and estimate the structural model. These attack matrices identify diversion ratios and hence comparative advertising damage measures. We find that outgoing comparative advertising attacks are half as powerful as self-promotion in raising own perceived quality and cause more damage to the targeted rival than benefit to the advertiser. Comparative advertising causes most damage through the pull-down effect and has substantial benefits to other rivals.

  • lundi 6 février 2012 , 14h15 à 15h45
Intervenant Sophie Lecostey Université de Caen Basse-Normandie, CREM
Invité par / invited by Séminaire interne
Thème / Subject Effets de la protection de l’emploi sur la localisation des firmes
Titre / title Fluctuating demand and oligopoly : is strong employment protection legislation detrimental to the domestic industry ?
Résumé / abstract It is often argued that firms need flexibility in order to better face demand uncertainty. As employment protection legislation (EPL) impacts the cost of volume adjustments available to the firms, it constrains volume flexibility that firms can achieve. Weakening EPL could then be thought as a desirable policy, in particular when firms decide where to locate. On the other hand, it is well known that in an oligopolistic setting, flexibility is not necessarily an advantage. The aim of this paper is to analyze the consequences that different EPL between countries may have on firms’ location decisions. It shows that the country characterized by the stronger EPL can nevertheless attract firms under demand uncertainty, and highlights the role played by transport costs.

  • lundi 16 janvier 2012 , 14h15 à 15h45
Intervenant Jean Bonnet Université de Caen Basse-Normandie, CREM
Invité par / invited by Séminaire interne
Thème / Subject Entrepreneurial orientation, financial policy, survival and growth of new firms
Titre / title Firm start-up strategies and performance in France : Survival and growth
Co-auteurs/Joint work with Nicolas Le Pape and Teresa Nelson
Résumé / abstract Essential performance outcomes of the new firm, including survival and growth, are related to financial and operational factors of the firm. We present a model that shows that firm financing via debt has some influence on types of market outreach, survival, and also growth of new firms in France. Using a robust, longitudinal dataset of the population of firms throughout the country established, continuing, and closing over the period of 2002 to 2007 (available through the French government via the SINE Survey : Système d’informations sur les nouvelles entreprises), we show that for a given indebtedness of the new firm, the entrepreneurial behavior generally improves the survival and the growth of new ventures.

  • lundi 12 décembre 2011 , 14h15 à 15h45
Intervenant Andreas Ortmann Australian School of Business, University of New South Wales
Invité par / invited by Benoît Walraevens
Thème / Subject Group Incentives vs. Individual Incentives, Experimental Economics
Titre / title Group Incentives or Individual Incentives ? A Real-Effort Weak-Link Experiment
Co-auteurs/Joint work with Stefania Bortolotti and Giovanna Devetag
Résumé / abstract Motivated by previous research on coordination problems and incentive design in organizations, we compare group incentives and individual incentives in a new experimental test-bed : a real-effort task embedding a weak-link lab coordination game technology. Comparing group incentives and individual incentives, we find that the observed dynamics of both individual errors and worst performances within firms are largely indistinguishable, suggesting that firm-based incentives are as effective as individual-based incentives in the present context. Simulations suggest that, in our test-bed, production costs are lower and profits are higher under group incentives. We find that more than 80 percent of our laboratory firms, notwithstanding initially widespread inefficiency, were eventually able to achieve and sustain efficient coordination, despite the presence of extremely unforgiving payoff structure. This result stands in stark contrast to standard results in the coordination game literature and provides an interesting challenge to test-beds currently used.

  • lundi 5 décembre 2011 , 14h15 à 15h45
Intervenant Ouattara kadohognon Sylvain Université de Caen Basse-Normandie
Invité par / invited by Séminaire interne
Thème / Subject Duopole mixte, incitations managériales, privatisation partielle
Titre / title Incitations managériales dans un duopole mixte : cas de privatisation partielle de la firme publique
Résumé / abstract Cet article étudie les incitations managériales dans un duopole mixte composé d’une firme semi-publique et d’une firme privée. Nous montrons que lorsque ces deux firmes offrent à leurs gestionnaires un contrat incitatif basé sur une combinaison linéaire de l’objectif des propriétaires de la firme et du chiffre d’affaires, le bien-être social augmente. Aussi, la décision endogène de donner (ou pas) une incitation aux gestionnaires est analysée. A l’équilibre parfait en sous-jeu (dans lequel les autorités publiques déterminent en amont le degré d’ouverture optimal du capital de la firme publique), seule la firme publique incite son gestionnaire. A cet équilibre, les autorités publiques n’ont pas intérêt à ouvrir le capital de la firme publique.

  • lundi 28 novembre 2011 , 14h15 à 15h45
Intervenant Daniel Danau, Université de Caen Basse-Normandie - CREM CNRS
Thème / Subject Théorie des contrats
Titre / title Optimal Contract with Private Information on Cost Expectation and Variability
Co-auteurs/Joint work with Annalisa Vinella
Résumé / abstract A multidimensional-and-sequential screening problem arises in a framework where the agent is privately informed about expected cost and cost variability and, subsequently, learns the realized cost as well. As the principal’s marginal surplus function proceeds from concave to convex, the optimal mechanism reflects increasingly stronger incentives to mimic less inefficient types and to misrepresent one information dimension rather than the other. When the principal’s knowledge imperfection about cost variability is sufficiently less important than that about expected cost, quantities are pooled with respect to the former for a high-expected-cost agent. A low-expected-cost agent may not be assigned the first-best output.

  • lundi 21 novembre 2011 , 14h15 à 15h45
Intervenant Yukio Koriyama, École Polytechnique
Invité par / invited by Vincent Merlin
Thème / Subject Voting Power, Individual and Collective Decision-Making
Titre / title Optimal Apportionment (pdf - 266 Ko)
Co-auteurs/Joint work with Antonin Macé, Jean-François Laslier and Rafael Treibich
Résumé / abstract This paper provides a theoretical foundation which supports the degressive proportionality principle" in apportionment problems. The core of the argument is that each individual derives utility from the fact that the collective decision matches her own will with some frequency, with marginal utility being decreasing with respect to this frequency. Then classical utilitarianism at the social level recommends decision rules which exhibit degressive proportionality. The model is applied to the case of the 27 states of the European Union.

  • lundi 14 novembre 2011 , 14h15 à 15h45 - Séminaire interne
Intervenant Benoït Walraevens, Université de Caen Basse-Normandie - CREM CNRS
Thème / Subject La réciprocité en économie
Titre / title Adam Smith et les théories économiques de la réciprocité
Résumé / abstract Il existe de manière schématique, deux grandes conceptions de la réciprocité en économie qui renvoient à deux visions de la nature humaine. La première a pour cadre de référence le modèle de l’homo economicus et explique, dans la lignée des théories biologistes de la kin selection ou de l’atruisme réciproque, et à partir de la théorie des jeux répétés, les comportements de réciprocité par la maximisation de l’intérêt personnel de long terme. La seconde, plus récente, s’appuie sur le modèle de l’homo reciprocans et met en avant la dimension sociale et morale des comportements de réciprocité. L’objet de cet article est de reconstruire, à partir des textes d’Adam Smith, une théorie générale de la réciprocité qui explique et approfondisse les résultats des théories économiques. Il est organisé en quatre parties. Dans la première et la seconde nous présentons le contenu des analyses smithiennes de la réciprocité positive et négative entre deux individus à travers ses descriptions de la gratitude et du ressentiment. La troisième partie développe la norme de réciprocité entre deux individus, soit les conditions d’une juste réciprocité positive ou négative. Celle-ci s’appuie sur sa théorie du mérite de l’action, et dépend dès lors de l’intentionnalité, des motifs et des conséquences de l’action. La quatrième partie présente l’extension du modèle d’interaction bilatérale réciproque à travers les analyses de la réciprocité indirecte et de la formation d’une norme sociale de réciprocité essentielle à l’ordre, à la stabilité et au bonheur de la société en favorisant la justice et la bienfaisance.

  • lundi 26 septembre 2011 , 14h15 à 15h45
Intervenant Stéfan Napel, Université de Bayreuth
Invité par / invited by Vincent Merlin
Thème / Subject Equal Representation, Collective Choice, Voting Power, Constitutional Design
Titre / title On the Egalitarian Weights of Nations
Co-auteurs/Joint work with Sascha Kurrz and Nicola Maaser
Résumé / abstract "Political decisions are frequently taken in assemblies by delegates who vote on behalf of their respective constituencies. Many such institutions assign different voting weights to the delegates (e.g., in the EU Council of Ministers), or equivalently involve delegations of different sizes who vote as a single block (e.g., US Electoral College), on the ground that
constituencies differ in population size. While voting weights (or seats) proportional to population size seem the most straightforward allocation rule, Penrose (1946) argued that
weights should be such that voting power of a constituency (as measured by the Penrose-Banzhaf index) is proportional to the square root of its population. This rule implements the “one person, one vote” principle in binomial choice environments ; it equalizes the indirect influence of all citizens on collective decisions a priori. This paper shows that Penrose’s rule also applies in non-dichotomous median voter environments if a 50% threshold is used in the assembly and voters’ ideal policies are independently and identically distributed. It does not extend to supermajority rules. And interim heterogeneity between constituencies calls for proportionality just to population size.
"