Dans un contexte économique mondialisé, hyperconcurrentiel, en situation de crise, les entreprises initient des stratégies collectives (Astley et Fombrun, 1983). Les stratégies collectives (Le Roy, 2006) caractérisent des relations horizontales de grand nombre, au sein desquelles des concurrents créent une structure fédérative de coordination. Elles s’observent particulièrement sur des secteurs où évoluent de nombreuses PME, ces entreprises restant plus vulnérables aux forces de l’environnement et devant lier leur destin pour survivre. L’étude de cas du syndicat de vignerons du Pic Saint-Loup, qui a conduit à réaliser quarante-cinq entretiens semi-directifs, combinés à de l’observation directe confortée par une position de professionnel du secteur, a mis en lumière un certain nombre de résultats. D’une part, des déterminants psychologiques influent sur la capacité des dirigeants à s’impliquer dans des stratégies collectives. D’autre part, des groupes d’acteurs, dont les instigateurs de la stratégie, occupent une place centrale au sein du réseau de dirigeants et en retirent une performance économique supérieure. Enfin, concernant les modalités, principalement la gestion du paradoxe par le dirigeant impliqué dans la stratégie collective, l’analyse des phases de concurrence et de collaboration met en évidence une discontinuité des flux qui engendre un processus d’alternance de fonctions. / In a globalized economy and crisis context, companies initiate collective strategies (Astley and Fombrun, 1983). Collective strategies (Le Roy, 2006) characterize horizontal relationships of large numbers, in which competitors create a federal structure of coordination. They occur particularly on sectors where many SMEs operate, these companies remain vulnerable to environmental forces and need linking their destiny to survive. The case study of Pic Saint-Loup winegrowers Union, which led to realize forty-five semi-structured interviews, combined with direct observation supported by a professional position in the industry, highlighted some number of results. On the one hand, psychological determinants affect the ability of managers to engage in collective strategies. On the other hand, stakeholder groups, including the instigators of the strategy, make superior economic performance out of this central position within the manager network. Finally, the management paradox by the manager involved in collective strategy analyzes, show analysis phases of competition and collaboration and highlights a discontinuity of flow which generates an alternating functions process.

L’œuvre philosophique de Kierkegaard s’apparente à une dialectique du paradoxe. De fait, dans son cheminement existentiel, l’individu parcourt trois sphères d’existence – l’esthétique, l’éthique et le religieux –, chacune d’elle étant une modalité de l’activité humaine qui comporte un paradoxe particulier. Il s’agit d’un itinéraire de l’intériorité qui vise, dans l’existence, le télos qu’est le devenir soi-même. Ainsi l’esthéticien est-il déchiré entre les idées et la réalité dans la réalité immédiate, tandis que l’éthicien, par la médiation du langage, préfère s’affirmer comme individu dans l’immanence concrète, ignorant toutefois qu’il intériorise des règles sociales qui lui sont impersonnelles. Quant au religieux, non seulement découvre-t-il que la vérité vers laquelle il tend ne se trouve pas en son sein, mais il fait face au plus élevé des paradoxes, fondé sur la transcendance – à savoir le paradoxe absolu, où l’éternité se temporalise sous la forme de l’Homme-Dieu. Du reste, le présent mémoire se penche spécifiquement sur le concept du paradoxe, mis de l’avant par Kierkegaard afin de brosser un portrait du devenir individuel de chaque existant. / The philosophical work of Kierkegaard deals with a dialectic of the paradox. Actually, in his existential progress, the individual goes through three spheres of existence – the aesthetic, the ethical and the religious –, each of which is a modality of the human activity that contains a particular paradox. His thought follows the progress of interiority, which aims, in existence, at the end of becoming a single individual. In this way, the aesthete is torn between the pure idea and reality, whereas the ethicist, through the mediation of language, prefers to assert himself as an individual within concrete immanence, ignoring however that he interiorizes social rules which are impersonal him. As for the religious believer, not only does he discover that the truth at which he aims is not within himself, but he faces the highest of the paradoxes, based on transcendance – that is the absolute paradox, whereby eternity temporalizes itself in the shape of the Man-God. In general, the present master’s thesis analyzes the concept of the paradox put forward by Kierkegaard to present the progress of every existing being towards becoming a single individual.

Le Paradoxe de la redistribution de Walter Korpi et Joakim Palme (1998) postule que les États-providences qui ont des dépenses sociales moins ciblées redistribuent davantage. Ive Marx, Lina Salanauskaite et Gerlinde Verbist (2013) ont toutefois constaté que le paradoxe démontré grâce à une corrélation entre un indice de redistribution et un indice de ciblage des dépenses sociales n'était plus valide dans les années 2000. En reproduisant les corrélations, il apparaît que l'augmentation importante du ciblage dans des pays qui redistribuent beaucoup comme le Danemark et la Suède est la principale cause de la disparition de la corrélation entre redistribution et ciblage. Lors des crises économiques dans les années 1980 et 1990, les prestations maximales déjà relativement faibles ainsi que la volonté de maintenir les prestations minimums et les taux de remplacement de la part des partis sociaux-démocrates ont poussé les gouvernements danois et suédois à réduire les prestations maximales afin de limiter l’augmentation des dépenses, augmentant ainsi le ciblage des dépenses sociales tout en préservant le caractère universel des programmes. L’augmentation du ciblage des dépenses sociales n’a pas eu d’effets négatifs sur la redistribution particulièrement au Danemark où la redistribution a augmenté et les inégalités diminué entre la fin des années 80 et le milieu des années 2000. / The Paradox of redistribution by Walter Korpi and Joakim Palme (1998) posits that welfare states that have less targeted social spending redistribute more. However, Ive Marx, Lina Salanauskaite and Gerlinde Verbist (2013) found that the correlation between the social spending targeting index and the redistribution index that demonstrates the paradox has weakened in the 2000s. By replicating the correlations, it seems that the increase targeting of social spending in countries with high redistribution like Denmark and Sweden is the main cause behind the weakening of the correlation between targeting and redistribution. During the economic crisis of the 80s and 90s, the already low maximum benefits and the will of social-democratic parties to maintain the minimal benefits and replacement rate led Danish and Swedish governments to reduce maximum benefits to restrain the increase of social spending, thus increasing the targeting of social spending without sacrificing universalism.

La pauvreté est souvent mise en exergue pour expliquer la présence des enfants dans les rues des pays pauvres. Cependant, le problème est plus complexe. En effet, certains enfants, bien qu’ayant la possibilité de vivre à l’abri du besoin préfèrent vivre dans la rue malgré l’hostilité de ce milieu. Aussi, de par la dimension culturelle, leur présence dans la rue semble incohérente en Afrique subsaharienne, car l’enfant « seul » n’existe pas, ce dernier appartient au groupe et non à ses seuls géniteurs.Comment alors expliquer cette présence ? Face à ce problème nous avons avancé les hypothèses suivantes :1) « L’enfant de la rue » serait dans la rue à cause d’une situation d’impasse familiale. 2) « L’enfant de la rue » adopterait des conduites paradoxales, qui atteignent ses enveloppes corporelles, pour survivre dans le milieu hostile de la rue. Notre investigation s’est déroulée au Gabon en deux temps. La première fait partie d’une plus large étude (UNICEF), nous avons administré 300 questionnaires auprès des enfants et rencontré 9 familles. Lors de la seconde, nous avons mené des entretiens et observations auprès de 25 enfants.L’analyse s’est effectuée en deux temps :- Premièrement nous avons décrit ces phénomènes, dressé un portrait de ces enfants, et établi leurs profils ainsi ceux de leur famille, avec l’aide d’une analyse de contenus (logiciel Nvivo).- Deuxièmement, nous avons montré à partir de quatre cas cliniques la difficulté qu’a l’enfant de s’autonomiser face à une famille/culture devenue « hybride ». Nos hypothèses se vérifient avec l’établissement de différents profils cliniques (l’enfant « aliéné », « pacificateur », «sans enveloppe psychique» …) qui décrivent l’impasse et la précarité psychique, ainsi que la constitution d’une « seconde peau-maison » en guise de peau psychique. Cette étude permet d’envisager la mise en place de nouveaux dispositifs où les liens « enfant-famille-professionnel » pourraient trouver un ajustement face à l’incohérence des modèles culturels. / Poverty is often highlighted to explain the presence of children in the streets of poor countries. However, the problem is way more complex. Indeed, some children, even if they don’t have to, prefer to live in the streets despite the hostility of this environment. Furthermore, according to the cultural dimension, their presence in the streets seems incoherent in Sub-SaharanAfrica, because the child “alone” doesn’t exist, he is part of a group, other than his immediate family. How can this presence be explained, then? In order to face this problem we formulated the following hypotheses.1) The “street child” would be in the streets because of a family impasse. 2) The “street child” would adopt paradoxical behaviors that reach their body envelopes in order to survive the hostilityof the environment. Our research took place in Gabon in two stages. The first one is part of a larger study (UNICEF), we administered 300 questionnaires to children and met with 9 families. During the second one, we conducted interviews and observations with 25 children.The analysis was executed in two times:- Firstly, we described these phenomena, we created a portrait of these children, and established their profiles and those of their families by means of a content analysis (Nvivo software)- Secondly, we demonstrated, based on four clinical cases, the child’s difficulty to become autonomous when confronted with a family/culture that’s turned “hybrid”.Our hypotheses are verified with the establishment of different clinical profiles (the “alienated” child, the “pacemaker”,“without psychic envelope”…) that describe an impasse and a psychic precariousness, as well as the construction of a “homesecondskin” as a way of psychic skin. This study allows to contemplate the establishment of new measures where the link “child-family-professional” could find an adjustment when confronted with the incoherence of cultural models.

L’état de santé des dirigeants de PME se dégrade. En effet, comme le soulignent certaines études (INRA, 2010; Observatoire AMAROK, 2012; MMA/Opinion Way, 2016), l’incertitude, les défaillances de trésorerie ou encore la surcharge de travail, seraient à l’origine du stress professionnel qui occasionnerait des maux chroniques. Cependant, seul un patron sur dix s’autoriserait un arrêt de travail. Dans ce contexte, Olivier TORRES en 2009 crée l’observatoire AMAROK et lance un vaste programme de recherches qui s’intéresse aux apports d’une démarche santé dans les sciences de gestion et, plus particulièrement, centré sur la personne même du dirigeant de PME. En effet, depuis quelques années, les démarches de prévention santé au travail suscitent un intérêt croissant de la part des pouvoirs publics et sont désormais inscrites au rang des devoirs du dirigeant envers ses salariés. Cependant, les études s’intéressant à la santé des dirigeants de PME restent aléatoires. S’inscrivant dans la lignée des développements d’auteurs comme RICHE (1998), TORRES et al. (2012), HERCBERG (2013), notre analyse invite ainsi à considérer la question de la santé du dirigeant de PME comme un outil de gestion responsable. Nous mobilisons les travaux sur les spécificités qui caractérisent le monde PME (MARCHESNAY, 1981, 1993; JULIEN, 1994; MAHE DE BOISLANDELLE, 1996; TORRES, 1997, 1998, 1999; FONROUGE, 2002), sur l’empreinte de l’environnement (DUVIGNAUD, 1977; FISCHER, 2011; TORRES 2012), le travail et la santé (LESAGE, 2012), ainsi que la modernité des pratiques alimentaires (FISCHLER, 1990; GAUDILLIERE 2001; POULAIN, 2002). Dans ce travail doctoral, nous cherchons d’une part à comprendre dans quelle mesure les déterminants caractérisant le métier de dirigeant de PME influent sur ses pratiques alimentaires, et, d’autre-part, à déterminer les causalités sur sa santé et celle de son entreprise. Sur le plan méthodologique, ce travail s’inscrit en premier lieu dans une étude exploratoire, s’appuyant sur les réponses apportées, à la suite d’une enquête par questionnaire, par l’échantillon de dirigeants de PME de la première cohorte de l’observatoire AMAROK. Les résultats de l’étude exploratoire mettent en exergue le rôle des marqueurs identitaires et nous conduisent à mener une étude qualitative compréhensive, en élaborant une deuxième grille de lecture considérant les notions de temps, de bien-être et de performance. Quatre principaux résultats émanent de notre recherche. En premier lieu, nous mettons en avant que suivant leurs marqueurs identitaires, les comportements alimentaires et de santé diffèrent. La proximité fonctionnelle du dirigeant place ce dernier dans une posture à la fois de sujet et d’objet, l’amenant à percevoir l’environnement et les autres d’une manière spécifique. Dans ce contexte, nous constatons que la taille de l’entreprise et l’entourage proche influencent ses pratiques alimentaires. Dans un deuxième temps, nous identifions que les pratiques alimentaires et compensatoires du dirigeant impactent sa santé et inversement. Il apparait que le dirigeant de PME est globalement sensible aux pressions exercées par la société civile et à la notion de risque. Troisième constat, les facteurs liés aux métiers de dirigeant de PME influencent sa santé. Nous pointons du doigt les effets délétères et « salutogènes » du travail sur la santé physique et psychique. Puis, nous identifions que les dirigeants ont une utilisation fonctionnelle de l’alimentation, qui dépendrait de leur surcharge de travail, de leur état d’esprit et de leur genre. Enfin, nous proposons une vision de la contribution d’une démarche unissant santé du dirigeant de PME etgestion. / The health of the leaders of SME (Small and Medium-sized Entreprise) degrades. Indeed, as underline it certains studies (INRA, 2010; Monitoring center AMAROK, 2012; MMA/Opinion Way, 2016), the uncertainty, the failures of finance or still the working overload, would be at the origin of the professional stress which would cause chronic troubles. However, only a boss on ten would adduce a sick leave (work stoppage). In this context, Olivier TORRES in 2009 creates the AMAROK observatory and launches a vast research program which are interested in the contributions of an initiative health in the science of management and more particularly centered on the person of the leader of SME. Indeed, since a few years, the steps of prevention health in the work arouse an interest growing on behalf of public authorities and are registered from now on to the rank of the homework of the leader to his employees. However, the studies being interested in the health of the leaders of SME remain random. Joining the lineage of the developments of authors as RICH (1998), TORRES and al. (2012) HERCBERG (2013), our analysis so invites to consider the question of the health of the leader of SME one responsible management tool. We mobilize the works on the specificities which characterize the world SME (MARCHESNAY, on 1981, on 1993; JULIEN, on 1994; MAHE OF BOISLANDELLE, on 1996; TORRES, on 1997, on 1998, on 1999; FONROUGE, on 2002), on the imprint of the environment (DUVIGNAUD, on 1977; FISCHER, on 2011; TORRES on 2012), the work and the health (LESAGE, on 2012;), as well as the modernity of the food practices (FISCHLER, on 1990; GAUDILLIERE on 2001; FOAL, on 2002).In this doctoral work, we try on one hand to understand to what extent determiners caractérisants the job by leader of SME influential on its food practices, and on the other hand to determine the causalities on his health and that of his company.On the methodological plan, this work joins first of all in an exploratory study, leaning on the brought answers, following an investigation by questionnaires, by the sample of leaders of SME of the first cohort of the monitoring center AMAROK. The results of the exploratory study highlight the role of the identical markers and lead us to lead a comprehensive qualitative study, by developing the second key for reading considering the notions of time, well-being and performance.Four main results emanate from our search. First of all, we put forward that according to their identical markers, eating habits and of health different. The functional closeness of the leader places him in a posture at the same time of subject and object, bringing him to perceive the environment and the others in a specific way. In this context, we notice that the size of the company and the close entourage influence its food practices. Secondly, we identify that the food and compensatory practices of the leader impact on its health and vice versa. It seems that the leader of SME is globally sensitive to the pressures exercised by the civil society and the notion of risk. The third report, the factors bound to the jobs by leader of SME influence its health. We point at the noxious effects and "salutogènes" of the work on the physical and psychic health. Then, we identify that the leaders have a functional use of the food, which would adapt itself to the stoneware of their working overload, their state of mind and their kind. Finally, we propose a vision of the contribution of an approach uniting health of the leader of SME and management.Keywords: SME(SMALL AND MEDIUM-SIZED ENTERPRISE), health of the leader, the food practices, the paradox well-being / performance.

La région sahélienne est caractérisée, depuis la moitié du XXème siècle, par un déficit pluviométrique important marqué par de fortes sécheresses en 1972-73 et en 1983-84 qui ont eu des effets considérables sur l'écosystème, les ressources et la population locale. Les réponses hydrologiques induites par ce déficit se traduisent par des effets contrastés suivant la zone géographique considérée. Si dans la zone soudano-guinéenne, une baisse des écoulements de surface a été observée, la zone sahélienne, paradoxalement, a connu une augmentation de ces écoulements durant la même période. La plupart des études visant à mieux comprendre cette évolution paradoxale ont été effectuées en milieu sahélien cultivé, où l'augmentation du ruissellement a souvent été attribuée au changement d'usage des sols suite aux besoins de la population croissante. Toutefois, ce même phénomène est aussi observable dans les zones majoritairement pastorales où les modifications d'usage des sols ne suffisent pas à expliquer les modifications hydrologiques observées. Les objectifs de cette thèse consistent à étudier, au travers de la modélisation hydrologique, l'évolution conjointe des différents processus régissant l'hydrologie sahélienne et de hiérarchiser leurs impacts sur l'évolution du ruissellement de surface sur les 50 dernières années en milieu pastoral. Pour ce faire, le modèle de ruissellement KINEROS2, a été appliqué au bassin versant d'Agoufou. Ce bassin de type endoréique est situé dans la région du Gourma, au Mali et est instrumenté par le service d'observation AMMA-CATCH qui fournit une partie des données nécessaires au forçage et à l'évaluation du modèle. La première partie de ces travaux a été dédiée à la quantification des changements survenus au cours des 50 dernières années sur ce bassin ainsi qu'au niveau de son exutoire, le lac d'Agoufou. Une cartographie des unités paysagères identifiées à partir d'images satellite et de photographies aérienne, a été réalisée pour les années 1956 et 2011. Cette cartographie a mis en évidence l'évolution des états de surface, marquée par l'érosion des sols peu profonds et la dégradation de la végétation de type brousse tigrée en faveur de l'extension des surfaces de sols nus (+35 km² entre 1956 et 2011) ainsi que par l'augmentation de la densité du réseau de drainage (×1.5) et par celle de la superficie du lac (534 m² en 1956 pour 2×106 m² en 2011). L'évolution du débit au cours du temps a été quantifiée à partir des variations de volume du lac établies via une relation entre les surfaces estimées par télédétection et les hauteurs d'eau mesurées in-situ. Cette relation a été couplée à une équation de bilan d'eau, prenant en compte les précipitations, l'évaporation et l'infiltration sur le lac pour quantifier les apports d'eau à l'exutoire. Nous avons ainsi mis en évidence l'évolution nette du coefficient de ruissellement du bassin qui est passé de 0% dans les années 1970 à 5.5 % dans les années 2000. La deuxième partie de cette thèse a été consacrée à la modélisation hydrologique et à la réalisation de simulations de références et d'attribution des changements observés à différents facteurs. L'augmentation des surfaces de sols nus associée à une diminution de la végétation explique largement l'évolution de l'hydrologie de surface du bassin depuis les années 1960. Le développement du réseau de drainage et l'encroûtement des dunes jouent des rôles secondaires dans cette évolution. En revanche, la variation du régime des pluies, tend à diminuer le ruissellement au cours du temps de plus de 34%. Les mécanismes identifiés sur le bassin d'Agoufou montrent l'importance de la dynamique du système couplé végétation/érosion/réseau hydrique et de leurs rôles sur d'autres bassins Sahéliens où l'augmentation du ruissellement a été également mise en évidence. / Since the mid-twentieth century, the Sahel is characterized by a significant rainfall deficit marked by severe droughts in 1972-73 and 1983-84 that have significantly impacted ecosystems, resources and local population. The responses induced by this deficit result in opposite effects according to geographical area. If, in the Sudano-Guinean zone, a reduced surface runoff was observed, the Sahel experienced a paradoxical increase of surface runoff during the same period. Most of the studies aiming at understanding this paradoxical situation have been performed in crop-dominated areas, where the runoff increase has been attributed to land use change following population growth. However, the same phenomenon is also observed in pastoral areas where land use change cannot explain the observed hydrological changes. The objective of this thesis is to study the different processes governing Sahelian hydrology and prioritize their impact on the surface runoff evolution in pastoral areas by means of hydrological modeling. To do this, the KINEROS2 runoff model was applied to the Agoufou watershed. This endorheic watershed is located in the Gourma region, in Mali. It is instrumented by the AMMA-CATCH observatory, which provides most of the necessary data for forcing and evaluating the model. The first part of this work was dedicated to the quantification of the changes occurred over the last 50 years on the Agoufou watershed and its outlet, the Agoufou lake. Land cover maps derived from satellite images and aerial photographs for 1956 and 2011 allowed estimating the changes in surface characteristics. Erosion of shallow soil and degradation of the tiger bush vegetation in favor of the bare soil extension (35 km² between 1956 and 2011) as well as increases in drainage density (× 1.5) and in lake area (534 m² in 1956 to 2 x 106 m² in 2011) were the main changes observed. The discharge evolution over time was quantified from changes in lake's volume, computed via a relationship between the lake's surface estimated by remote sensing and in-situ water height data. This relationship was coupled to a water balance equation, taking into account precipitation, water evaporation and lake's bottom infiltration to quantify the water inflow to the lake. The runoff coefficient of the watershed was shown to increase from 0 % in the 1970s to 5.5% in the 2000s. The second part of this thesis was dedicated to hydrological modeling in order to rank the impact of the surface changes highlighted above on runoff. Series of reference and attribution simulations were performed. The increase in bare soil surfaces associated with a decrease in vegetation largely explains the hydrological changes of the watershed since the 1960s. The development of the drainage network and the crusting of sandy dunes play a less important role on this evolution, while the evolution of daily precipitation reduces runoff over time by more than 34%, which contradicts the observed trend. The mechanisms identified in the Agoufou watershed highlight the pivotal role of the dynamics of the coupled vegetation/erosion/drainage network system and their role in other Sahelian regions, where increased runoff was also observed.

Dans la plupart des situations concrètes de choix, les décideurs ne peuvent pas prédire le résultat de leur action avec certitude. La théorie de la décision distingue généralement entre le cas typique du risque, où les probabilités des différents événements sont connus objectivement, et la situation de l'ambiguïté, où le contexte informationnel ne permet pas d'établir de telles probabilités objectives.Cependant, les agents détiennent souvent de l'information partielle sous la forme d'ensembles d'observations passées, conduisant à des situations qui dépassent la dichotomie traditionnelle entre probabilités connues et inconnues.Cette thèse fournit une analyse empirique des comportements de décision en situation d'incertitude lorsque de l'information statistique est disponible. Les deux premiers chapitres portent sur les comportements de choix en présence d'information, c'est-à-dire lorsque les différentes options sont décrites par des ensembles de données ex ante. Ces chapitres étudient l'influence de la précision de l'information sur la perception de l'ambiguïté et sur les attitudes vis-à-vis du risque et de l'ambiguïté.Dans le troisième chapitre, je considère le cas dans lequel les agents ne sont pas informés et ont l'opportunité d'acquérir de l'information. Ce chapitre propose une expérience dont l'objectif est d'étudier la manière dont les individus évaluent l'information additionnelle. / In most real-life choice situations, decision makers cannot predict the outcome of their action with certainty. Decision theory generally distinguishes between the typical case of risk, in which the probabilities of the different events are objectively known, and the situation of ambiguity, in which the informational context does not allow such objective probability judgment. However, agents are often provided with partial information consisting of past observations, leading to situations beyond the traditional known-unknown probabilities dichotomy.This thesis empirically investigates decision-making under uncertainty when statistical information is available. The first two chapters focus on choice behaviors in the presence of information, i.e., when prospects are described by datasets ex ante. These chapters study the influence of information precision on the perception of ambiguity and on the attitudes towards risk and ambiguity. In the third chapter, I consider the situation in which agents are uninformed and have the opportunity to acquire information. This chapter proposes an experiment designed to explore the individual valuation for additional information.

1. Contextual outline of the PhD Research Climate change is today often seen as one of the most challenging issue that our civilisation will have to face during the 21st century. This is especially so now that the most recent scientific data have led to the conclusion that the globally averaged net effect of human activities since 1750 has been one of warming (IPCC 2007, p. 5) and that continued greenhouse gas emissions at or above current rates would cause further warming (IPCC, 2007 p. 13). This unequivocal link between climate change and anthropogenic activities requires an urgent, world-wide shift towards a low carbon economy (STERN 2006 p. iv) and coordinated policies and measures to manage this transition. The climate issue is undoubtedly a typical policy question and as such, is considered amenable to economic scrutiny. Indeed, in today’s world economics is inevitable when it comes to arbitrages in the field of policy making. From the very beginning of international talks on climate change, up until the most recent discussions on a post-Kyoto international framework, economic arguments have turned out to be crucial elements of the analysis that shapes policy responses to the climate threat. This can be illustrated by the prominent role that economics has played in the different analyses produced by the Intergovernmental Panel on Climate Change (IPCC) to assess the impact of climate change on society. The starting point and the core idea of this PhD research is the long-held observation that the threat of climate change calls for a change of climate in economics. Borrowing from the jargon used in climate policy, adaptation measures could also usefully target the academic discipline of economics. Given that inherent characteristics of the climate problem (e.g. complexity, irreversibility, deep uncertainty, etc.) challenge core economic assumptions, mainstream economic theory does not appear as appropriately equipped to deal with this crucial issue. This makes that new assumptions and analyses are needed in economics in order to comprehend and respond to the problem of climate change. In parallel (and without environmental considerations being specifically the driving force to it), the mainstream model in economics has also long been (and still is) strongly criticised and disputed by numerous scholars - both from within and outside the field of economics. For the sake of functionality, these criticisms - whether they relate to theoretical inconsistencies or are empirically-based - can be subsumed as all challenging part of the Cartesian/Newtonian legacy of economics. This legacy can be shown to have led to a model imprinted with what could be called “mechanistic reductionism”. The mechanistic side refers to the Homo oeconomicus construct while reductionism refers to the quest for micro-foundations materialised with the representative agent hypothesis. These two hypotheses constitute, together with the conjecture of perfect markets, the building blocks of the framework of general equilibrium economics. Even though it is functional for the purpose of this work to present them separately, the flaws of economics in dealing with the specificities of the climate issue are not considered independent from the fundamental objections made to the theoretical framework of mainstream economics. The former only make the latter seem more pregnant while the current failure of traditional climate policies informed by mainstream economics render the need for complementary approaches more urgent. 2. Overview of the approach and its main insights for climate policy Starting from this observation, the main objective of this PhD is thus to assess the implications for climate policy that arise from adopting an alternative analytical economic framework. The stance is that the coupling of insights from the framework of evolutionary economics with the perspective of ecological economics provides a promising way forward both theoretically as well as on a more applied basis with respect to a better comprehension of the socioeconomic aspects related to the climate problem. As claimed in van den Bergh (2007, p. 521), ecological economics and evolutionary economics “share many characteristics and can be combined in a fruitful way" - which renders the coupling approach both legitimate and promising. The choice of an evolutionary line of thought initially stems from its core characteristic: given its focus on innovation and system change it provides a useful approach to start with for assessing and managing the needed transition towards a low carbon economy. Besides, its shift of focus towards a better understanding of economic dynamics together with its departure from the perfect rationality hypothesis renders evolutionary economics a suitable theoretical complement for designing environmental policies. The notions of path-dependence and lock-in can be seen as the core elements from this PhD research. They arise from adopting a framework which is founded on a different view of individual rationality and that allows for richer and more complex causalities to be accounted for. In a quest for surmounting the above-mentioned problem of reductionism, our framework builds on the idea of ‘multi-level selection’. This means that our analytical framework should be able to accommodate not only for upward but also for downward causation, without giving analytical priority to any level over the other. One crucial implication of such a framework is that the notion of circularity becomes the core dynamic, highlighting the importance of historicity, feedbacks and emergent properties. More precisely, the added value of the perspective adopted in this PhD research is that it highlights the role played by inertia and path-dependence. Obviously, it is essential to have a good understanding of the underlying causes of that inertia prior to devising on how to enforce a change. Providing a clear picture of the socio-economic processes at play in shaping socio-technical systems is thus a necessary first step in order to usefully complement policy-making in the field of energy and climate change. In providing an analytical basis for this important diagnosis to be performed, the use of the evolutionary framework sheds a new light on the transition towards low-carbon socio-technical systems. The objective is to suggest strategies that could prove efficient in triggering the needed transition such as it has been the case in past “lock-in” stories. Most notably, the evolutionary framework allows us to depict the presence of two sources of inertia (i.e at the levels of individuals through “habits” and at the level of socio-technical systems) that mutually reinforce each other in a path-dependent manner. Within the broad perspective on path dependence and lock-in, this PhD research has first sketched the implications for climate policy of applying the concept of ‘technological lock-in’ in a systemic perspective. We then investigated in more details the notion of habits. This is important as the ‘behavioural’ part of the lock-in process, although explicitly acknowledged in the pioneer work of Paul David (David, 1985, p. 336), has been neglected in most of subsequent analyses. Throughout this study, the notion of habits has been studied at both the theoretical and applied level of analysis as well as from an empirical perspective. As shown in the first chapters of the PhD, the advantage of our approach is that it can incorporate theories that so far have been presented opposite, partial and incomplete perspectives. For instance, it is shown that our evolutionary approach not only is able to provide explanation to some of the puzzling questions in economics (e.g. the problem of strong reciprocity displayed by individual in anonymous one-shot situations) but also is very helpful in bringing a complementary explanation with respect to the famous debate on the ‘no-regret’ emission reduction potential which agitates the experts of climate policy. An emission reduction potential is said to be "no regret" when the costs of implementing a measure are more than offset by the benefits it generates such as, for instance, reduced energy bills. In explaining why individuals do not spontaneously implement those highly profitable energy-efficient investments , it appears that most prior analyses have neglected the importance of non-economic obstacle. They are often referred to as “barriers” and partly relate to the ‘bounded rationality’ of economic agent. As developed in the different chapters of this PhD research, the framework of evolutionary economics is very useful in that it is able to provide a two-fold account (i.e. relying on both individual and socio-technical sources of inertia) of this limited rationality that prevent individuals to act as purely optimising agents. Bearing this context in mind, the concept of habits, as defined and developed in this study, is essential in analysing the determinants of energy consumption. Indeed, this concept sheds an insightful light on the puzzling question of why energy consumption keeps rising even though there is an evident increase of awareness and concern about energy-related environmental issues such as climate change. Indeed, if we subscribe to the idea that energy-consuming behaviours are often guided by habits and that deeply ingrained habits can become “counter-intentional”, it then follows that people may often display “locked-in” practices in their daily energy consumption behaviour. This hypothesis has been assessed in our empirical analysis whose results show how the presence of strong energy-consuming habitual practices can reduce the effectiveness of economic incentives such as energy subsidies. One additional delicate factor that appears crucial for our purpose is that habits are not fully conscious forms of behaviours. This makes that individuals do not really see habits as a problem given that it is viewed as easily changed. In sum, based on our evolutionary account of the situation, it follows that, to be more efficient, climate policies would have to both shift the incumbent carbon-based socio-technical systems (for it to shape decisions towards a reduction of greenhouse gas emissions) and also deconstruct habits that this same socio-technical has forged with time (as increased environmental awareness and intentions formulated accordingly are not sufficient in the presence of strong habits). Accordingly, decision-makers should design measures (e.g. commitment strategies, niche management, etc.) that, as explained in this research, specifically target those change-resisting factors and their key features. This is essential as these factors tend to reduce the efficiency of traditional instruments. Micro-level interventions are thus needed as much as macro-level ones. For instance, it is often the case that external improvements of energy efficiency do not lead to lower energy consumption due to the rebound effect arising from unchanged energy-consuming habits. Bearing this in mind and building on the insights from the evolutionary approach, policy-makers should go beyond the mere subsidisation of technologies. They should instead create conditions enabling the use of the multi-layered, cumulative and self-reinforcing character of economic change highlighted by evolutionary analyses. This means supporting both social and physical technologies with the aim of influencing the selection environment so that only the low-carbon technologies and practices will survive. Mentioned references: David, P. A. (1985), Clio and the economics of QWERTY, American Economic Review 75/2: 332–337. IPCC, 2007, ‘Climate Change 2007: The Physical Science Basis’, Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp. Stern, N., 2006, ‘Stern Review: The economics of Climate Change’, Report to the UK Prime Minister and Chancellor, London, 575 p. (www.sternreview.org.uk) van den Bergh, J.C.J.M., 2007, ‘Evolutionary thinking in environmental economics’, Journal of Evolutionary Economics 17(5): 521-549.

L’œuvre philosophique de Kierkegaard s’apparente à une dialectique du paradoxe. De fait, dans son cheminement existentiel, l’individu parcourt trois sphères d’existence – l’esthétique, l’éthique et le religieux –, chacune d’elle étant une modalité de l’activité humaine qui comporte un paradoxe particulier. Il s’agit d’un itinéraire de l’intériorité qui vise, dans l’existence, le télos qu’est le devenir soi-même. Ainsi l’esthéticien est-il déchiré entre les idées et la réalité dans la réalité immédiate, tandis que l’éthicien, par la médiation du langage, préfère s’affirmer comme individu dans l’immanence concrète, ignorant toutefois qu’il intériorise des règles sociales qui lui sont impersonnelles. Quant au religieux, non seulement découvre-t-il que la vérité vers laquelle il tend ne se trouve pas en son sein, mais il fait face au plus élevé des paradoxes, fondé sur la transcendance – à savoir le paradoxe absolu, où l’éternité se temporalise sous la forme de l’Homme-Dieu. Du reste, le présent mémoire se penche spécifiquement sur le concept du paradoxe, mis de l’avant par Kierkegaard afin de brosser un portrait du devenir individuel de chaque existant. / The philosophical work of Kierkegaard deals with a dialectic of the paradox. Actually, in his existential progress, the individual goes through three spheres of existence – the aesthetic, the ethical and the religious –, each of which is a modality of the human activity that contains a particular paradox. His thought follows the progress of interiority, which aims, in existence, at the end of becoming a single individual. In this way, the aesthete is torn between the pure idea and reality, whereas the ethicist, through the mediation of language, prefers to assert himself as an individual within concrete immanence, ignoring however that he interiorizes social rules which are impersonal him. As for the religious believer, not only does he discover that the truth at which he aims is not within himself, but he faces the highest of the paradoxes, based on transcendance – that is the absolute paradox, whereby eternity temporalizes itself in the shape of the Man-God. In general, the present master’s thesis analyzes the concept of the paradox put forward by Kierkegaard to present the progress of every existing being towards becoming a single individual.

Louis Jouvet a toute sa vie écrit et pensé l’art dramatique, s’essayant à tous les métiers du théâtre, depuis ses débuts en tant que régisseur jusqu’à ses expériences de metteur en scène et bien évidemment d’acteur. Dans ses leçons au Conservatoire, données de 1934 à 1940 puis de 1947 à 1951, il tente de mettre en mots, pour ses élèves, le « mystère » du théâtre, qui ne vit que dans l’instant du jeu et se dérobe sitôt celui-ci terminé. Il construit pour ce faire un édifice mental dont les personnages sont le cœur. Venus visiter les auteurs dramatiques véritables au moment de l’écriture, ils sont ceux dont l’acteur, s’il veut devenir comédien et parvenir à la désincarnation, doit se mettre en quête. Afin de comprendre comment Jouvet invente une logique qui lui permet à la fois de transmettre le fruit de son expérience et de maintenir l’énigme, nous avons procédé à une analyse systématique des classes. De celle-ci émerge non une « méthode » ou un « système » Jouvet mais une pensée moins contradictoire qu’il n’y paraît, portée par un vocabulaire inlassablement repris et d’où émergent de fortes constantes. La première partie de la thèse analyse la pensée générale du théâtre selon Jouvet et la place décisive qu’il accorde aux personnages, de façon à comprendre comment il situe son rôle d’enseignant du premier XXe siècle. La deuxième reprend et développe les différents modes d’approche des personnages dramatiques, selon leur genre, leur auteur et leur type. La troisième envisage plus spécifiquement le temps de la rencontre, dans le jeu, entre le comédien et le personnage, dans une redéfinition du Paradoxe de Diderot, dont Jouvet repense les termes selon la logique poético-mystique qu’il échaffaude. / Throughout his life, Louis Jouvet reflected on and wrote about the dramatic arts, exercising all of the different trades of the Theatre field, from his beginnings as a stage manager to his experiences as a director and, obviously, as an actor. In his lessons as a teacher at Paris’ drama school, from 1934 to 1940 and from 1947 to 1951, he strived to pass on to his students the “mystery” of the Theatre, alive only in the instant of the play and elusive as soon as it is over. To do so, he erects a mental structure whose pillars are the characters. As the inspirers of the genuine dramatic authors, the characters are the ones every actor must seek if he is to become a comedian and reach disembodiment. To understand how Jouvet invents a structure that would allow him to impart the lessons of his experience and, at the same time, maintain the mystery, we analyzed all of his lessons in a systematic way. From there, what comes to light is not a “Jouvet method” nor a “Jouvet system”, but a vision that’s not as contradictory as it would seem, supported by a very recurring vocabulary, and from which emerge a few strong constants.The Thesis’ first part analyzes Jouvet’s general vision of the Theatre and the key role he assigns to characters, as a means to understand how he defines his role as a teacher during the first half of the XXth century. The second part delves into Jouvet’s different perspectives on characters, according to genre, author and type. The third one explores more specifically the moment in which, through the play, comedian and character meet, in a redefinition of Diderot’s paradox reshaped by Jouvet’s original logic, both logical and mystic.