238 research outputs found
Graphical expression and designing : cognitive aspects of drawing operations in design and implications for computerised drawing environments
Utilitarianism with Prior Heterogeneity
URL des Documents de travail : http://ces.univ-paris1.fr/cesdp/cesdp2014.htmlDocuments de travail du Centre d'Economie de la Sorbonne 2014.49 - ISSN : 1955-611XHarsanyi's axiomatic justification of utilitarianism is extended to a framework with subjective and heterogenous priors. Contrary to the existing literature on aggregation of preferences under uncertainty, society is here allowed to formulate probability judgements, not on the actual state of the world as individuals do, but rather on the opinion they each have on the actual state. An extended Pareto condition is then proposed that characterizes the social utility function as a convex combination of individual ones and the social prior as the independent product of individual ones.La justification axiomatique de l'utilitarisme d'Harsanyi est généralisée à un cadre dans lequel les croyances individuelles sont subjectives et hétérogÚnes. A l'inverse de la littérature existante sur l'agrégation de préférences en environnement incertain, la société formule des jugements de probabilité, non pas sur le véritable état du monde - ce que les individus font -, mais plutÎt sur les opinions qu'entretiennent les individus à propos du véritable état du monde. Une forme étendue de la condition de Pareto est alors proposée et il est montré qu'elle caractérise l'utilité sociale en tant que combinaison convexe des utilités individuelles et la probabilité sociale en tant que produit indépendant des probabilités individuelles
Expected Utility without Parsimony
URL des Documents de travail : http://ces.univ-paris1.fr/cesdp/cesdp2014.htmlDocuments de travail du Centre d'Economie de la Sorbonne 2014.48 - ISSN : 1955-611XThis paper seeks to interpret observable behavior and departures from Savage's model of Subjective Expected Utility (SEU) in terms of knowledge and belief. It is shown that observable behavior displays sensitivity to ambiguity if and only if knowledge and belief disagree. In addition, such an epistemic interpretation of ambiguity leads to dynamically consistent extensions of non-SEU preferences.Ce papier cherche à interpréter le comportement observable d'un individu, et notamment les violations du modÚle d'espérance subjective d'utilité (SEU), en termes de savoir et de croyance. Il est montré que le comportement observable révÚle de la sensitivité à l'ambiguïté si et seulement si savoir et croyance diffÚrent. De plus, une telle interprétation épistémique de l'ambiguïté mÚne à des extensions dynamiquement cohérentes des préférences non-SEU
Dynamic Consistency and Expected Utility with State Ambiguity
While models of ambiguity are reputed to generate a basic tension between dynamic consistency and the Ellsberg choices, this paper identifies a third implicit ingredient of this tension, namely the parsimony rule, which enforces each state of nature to encode a well-defined unique observation. This paper then develops nonparsimonious interpretations of the state space to make the Ellsberg choices compatible with both expected utility and dynamic consistency. The state space may contain nonobservable states: a state is allowed to encode more than one observation, a pattern called state ambiguity. The presence of such ambiguous states motivates an explicit distinction between the decision-maker and the theory-maker, the latter designing the state space and eliciting the former's preferences
Infinite Supermodularity and Preferences
This chapter studies the ordinal content of supermodularity on lattices. This chapter is a generalization of the famous study of binary relations over finite Boolean algebras obtained by Wong, Yao and Lingras. We study the implications of various types of supermodularity for preferences over finite lattices. We prove that preferences on a finite lattice merely respecting the lattice order cannot disentangle these usual economic assumptions of supermodularity and infinite supermodularity. More precisely, the existence of a supermodular representation is equivalent to the existence of an infinitely supermodular representation. In addition, the strict increasingness of a complete preorder on a finite lattice is equivalent to the existence of a strictly increasing and infinitely supermodular representation. For wide classes of binary relations, the ordinal contents of quasisupermodularity, supermodularity and infinite supermodularity are exactly the same. In the end, we extend our results from finite lattices to infinite lattices
Lâinsolite dans les guides touristiques
Cet article sâintĂ©resse aux guides de voyage, plus particuliĂšrement Ă ceux qui invitent leurs lecteurs Ă dĂ©couvrir la âPataxie ou, plus prosaĂŻquement, les destinations (re-)qualifiĂ©es dââinsolitesâ. Ă partir de plusieurs Ă©tudes sĂ©miologiques menĂ©es sur des guides de voyage, conduites dans une perspective communicationnelle, il cherche dâune part Ă comprendre comment les dispositifs de mĂ©diation Ă©tudiĂ©s font de lâinsolite une valeur touristique pour mieux saisir, dâautre part, les spĂ©cifiĂ©s de cette derniĂšre. Il revient ainsi dâabord sur les stratĂ©gies rhĂ©toriques des guides de lâinsolite ; il montre en quoi lâinsolite est construit en rupture vis-Ă -vis du rĂ©gime de la curiositĂ©, dĂšs lors quâil repose sur une logique de la production des singularitĂ©s, au sens fort, soit des hapax. Il propose, ensuite, de montrer comment, dans le tourisme de lâinsolite, la pratique telle quâelle est programmĂ©e par les guides se voit requalifiĂ©e moins comme une expĂ©rience de lâaltĂ©ritĂ© que comme une expĂ©rimentation dâune somme dâhapax culturels. Enfin, il questionne la possibilitĂ© pour lâinsolite, dĂ©fini Ă travers la rhĂ©torique de la singularisation et la programmatique de lâexpĂ©rimentation, dâĂȘtre autre chose quâun territoire composĂ© dâĂ©clats ou â si lâon considĂšre le discours comme un faire â autre chose quâun processus de dĂ©mantĂšlement des cultures.This paper deals with travel guides and, more specifically, with French-written guides that invite their readers to discover a kind of so-called ânewâ destinations made of âinsoliteâ cultural products and situations. The French adjective âinsoliteâ has no English translation. It refers, though, to the realm of the unusual that seems to be, from a tourist point of view and according to travel guides, somehow different from the realm of curiosity. Analysing thus a series of travel guides to âinsoliteâ destinations through a communicational perspective, this paper aims to understand how these books have turned the âinsoliteâ into a tourist value and to identify its specificities. It firstly studies the differences âinsoliteâ travel guides have established between âinsoliteâ and curiosity focusing on the way they produce cultural hapax. It then shows that these guides construct a specific tourist practice â at least a program of practices â that resembles more the experiment of a series of cultural hapax than the experience of an other. Finally, it raises the question of the possibility for the âinsoliteâ, since it is defined as a rhetoric of singularization and a program of experimentations, to be something else than a territory made of bursts or, if one considers speeches as acts, something else than a process of dismantlement of cultures
Hécate Vergopoulos, Tourisme et curiosités. Approche communicationnelle du légendaire dans les guides de voyage imprimés
On considĂšre souvent que les guides de voyage sont des ouvrages qui ont pour seul objectif de proposer une modalitĂ© singuliĂšre dâappropriation de lâespace dans le cadre dâune pratique touristique. On nĂ©glige, alors, deux autres dimensions pleinement constitutives de ce genre de dispositifs : celle qui concerne la lecture et celle qui concerne le discours. Ă propos de la premiĂšre, on remarquera quâon trouve, dans les guides, une somme de petits dispositifs Ă©ditoriaux, tels que les sommaires, ..
Dynamic consistency of expected utility under non-classical(quantum) uncertainty
Quantum cognition is a recent and rapidely growing field. In this paper we developan expected utility theory in a context of non-classical (quantum) uncertainty.We replace the classical state space with a Hilbert space which allows introducing the concept of quantum lottery. Within that framework we formulate sufficient and necessary axioms on preferences over quantum lotteries to establish a representation theorem. We show that demanding the consistency of choice behavior conditional on new information is equivalent to the von Neuman-Luders postulate applied to beliefs. In our context, dynamic consistency is shown not to secure Savage's Sure Thing Principle (in its dynamic version). Finally, we discuss the interpretation and value of our results for rationality and behavioral economics
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