Short Run and Long Run Causality in Time Series: Inference

We propose methods for testing hypothesis of non-causality at various horizons, as defined in Dufour and Renault (1998, Econometrica). We study in detail the case of VAR models and we propose linear methods based on running vector autoregressions at different horizons. While the hypotheses considered are nonlinear, the proposed methods only require linear regression techniques as well as standard Gaussian asymptotic distributional theory. Bootstrap procedures are also considered. For the case of integrated processes, we propose extended regression methods that avoid nonstandard asymptotics. The methods are applied to a VAR model of the U.S. economy. Nous proposons des méthodes pour tester des hypothèses de non-causalité à différents horizons, tel que défini dans Dufour et Renault (1998, Econometrica). Nous étudions le cas des modèles VAR en détail et nous proposons des méthodes linéaires basées sur l'estimation d'autorégressions vectorielles à différents horizons. Même si les hypothèses considérées sont non linéaires, les méthodes proposées ne requièrent que des techniques de régression linéaire de même que la théorie distributionnelle asymptotique gaussienne habituelle. Dans le cas des processus intégrés, nous proposons des méthodes de régression étendue qui ne requièrent pas de théorie asymptotique non standard. L'application du bootstrap est aussi considérée. Les méthodes sont appliquées à un modèle VAR de l'économie américaine.time series; Granger causality; indirect causality; multiple horizon causality; autoregression; autoregressive model; vector autoregression; VAR; stationary process; nonstationary process;integrated process; unit root; extended autoregression; bootstrap; Monte Carlo; macroeconomics;money; interest rates; output; inflation, séries chronologiques; causalité; causalité indirecte; causalité à différents horizons; autorégression; modèle autorégressif; autorégression vectorielle; VAR; processus stationnaire; processus non stationnaire; processus intégré; racine unitaire; autorégression étendue; bootstrap; Monte Carlo; macroéconomie; monnaie; taux d'intérêt; production; inflation

A survey to evaluate how non designers perceive aesthetic properties of styling features

World-wide market competition and the need to create products that better satisfy the market expectations require a more comprehensive involvement of the customer in the product definition loop. Therefore, it is crucial to provide customers with very easy-to-use shape definition and modification tools, allowing them to verify and evaluate possible shape alternatives without requiring specific knowledge on geometric modeling. A set of aesthetic properties guiding the shape characterization and appraisal have been identified together with measures for their evaluation and shape modeling methods for their direct modification. Since these properties have been indicated by stylists, no guarantee exists that they are usable in a context directly involving customers in the product definition loop. To verify the extent to which the terms indicating the properties, their meaning and their measures are significant and understandable by non-expert designer people we carried out a survey. This paper describes the methodology adopted and the outcomes of this survey

On Jumps and Arch Effects in Natural Resource Prices. An Application to Stumpage Prices from Pacific Northwest National Forests

Models used for natural resources prices usually preclude the possibility of large changes (jumps) resulting from discrete, unexpected events. To test for the presence of jumps and ARCH effects, we propose to use bounds and bootstrap test techniques, thus solving the unidentified nuisance parameter problem. We apply this approach to stumpage price time series from the Pacific Northwest and find evidence of jumps and ARCH effects. Using real options, we then develop a stopping model to assess the impact of neglecting jumps on the decision to harvest old-growth timber. Our numerical results show the importance of modeling jumps explicitly.Jump processes, ARCH, Bootstrap, Stumpage prices, Real options

On Jumps and ARCH Effects in Natural Resource Prices. An Application to Stumpage Prices from Pacific Northwest National Forests

Models use for natural resources prices usually preclude the possibility of large changes (jumps) resulting from discrete, unexpected events. To test for the presence of jumps and ARCH effects, we propose to use bounds and bootstrap test techniques, thus solving the unidentified nuisance parameter problem. We apply this approach to stumpage price time series from the Pacific Northwest and find evidence of jumps and ARCH effects. Using real options, we then develop a stopping model to assess the impact of neglecting jumps on the decision to harvest old-growth timber. Our numerical results show the importance of modeling jumps explicitly.Jum Processes, ARCH, Bootstrap, Stumpage Prices, Real Options

20 NEW THERAPEUTIC STRATEGIES AND AGENTS WITH STRUCTURE MODIFYING POTENTIAL IN OSTEOARTHRITIS

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L'éveil dans le « Sûtra de Vimalakîrti »

Notre analyse porte sur la notion d’éveil au sein du Sûtra de Vimalakîrti. Premièrement, nous présentons et comparons les modèles d’éveil exposés dans ce texte, soit la figure du bouddha et – surtout – celle du bodhisattva; nous analysons leurs deux grands traits caractéristiques, c’est-à-dire la connaissance transcendante et les méthodes habiles, puis élaborons leur rôle par rapport à l’éveil. Il apparaît d’emblée que la connaissance transcendante est une connaissance non discursive de la réelle nature de toute chose et qu’elle est une condition nécessaire à l’éveil, alors que les méthodes habiles – aussi appelées expédients salvifiques – constituent la myriade de moyens rusés et provisoires conçus et employés par les bouddhas et bodhisattva dans le but d’amener les êtres ignorants à l’éveil et d’ainsi les libérer de l’attachement et de la souffrance. Dans le second chapitre, nous caractérisons l’état de conscience de l’éveillé à l’aide de notions telles la non-dualité, la non-discrimination et la non-pensée, puis présentons la conception de la pratique méditationnelle soutenue dans notre sûtra. Nous montrons que l’état d’éveil est un état de conscience non discriminateur au sein duquel l’identité personnelle et les phénomènes – ou la dualité sujet-objet – sont reconnus comme étant des illusions ou, plus précisément, des constructions mentales et langagières. Ainsi, la méditation apparaît comme étant une méthode habile provisoire dont les buts sont essentiellement la déconstruction du paradigme dualiste de la pensée discursive et la réalisation qu’il n’existe, ultimement et paradoxalement, aucune réelle entrave à l’éveil et aucune pratique méditationnelle nécessaire à l’expérience de l’éveil.Our analysis pertains to the notion of awakening in the Vimalakîrti Sûtra. Firstly, we present and compare the models of awakening exposed in this text, namely the figure of the buddha and – especially – that of the bodhisattva; we analyze their two major characteristic traits, that is to say transcendent knowledge and skillful means, and elaborate on their relation to awakening. We quickly find that transcendent knowledge is a non discursive knowledge of the real nature of all things and that it is a necessary condition to awakening, whereas skillful means – also called salvific expedients – constitute the myriad of clever and merely provisory means conceived and used by buddhas and bodhisattva in order to bring all ignorant beings to awakening and thus to liberate them from attachment and suffering. In the second chapter, we characterize the state of consciousness of the awakened through notions such as non-duality, non-discrimination and no-mind, and present the conception of meditational practice upheld in our sûtra. We show that the state of awakening is a non discriminating state of consciousness in which personal identity and phenomena – or the subject-object duality – are recognized as illusions or, more precisely, as mental and linguistic constructions. Meditation thus appears to be a provisory skillful mean, the goals of which are the deconstruction of discursive thought’s dualist paradigm and the realization that, ultimately and paradoxically, there exist no real obstacles to awakening and no necessary meditational practice to the experience of awakening