Teses / dissertações sobre o tema "Economie de la complexité"

L'économie, en ce qu’elle comporte des effets non-linéaires, une adaptabilité des agents et des dynamiques de hors-équilibre, présente des phénomènes émergents tels que des crises et des inégalités, induites par les réactions des agents et les interventions politiques.La modélisation basée sur les agents (agent based models en anglais, ou ABM) est une approche de modélisation récente en macroéconomie qui retrouve ces phénomènes en simulant une multiplicité d'agents hétérogènes en interaction.Bien que cette méthode puisse générer des phénomènes émergents, elle a souvent été critiquée comme étant une boîte noire où les mécanismes de causalité ne sont pas clairs et où il existe un ensemble trop vaste de dynamiques générées.Cette thèse propose une méthode pour aborder la question fondamentale : Quel est l'ensemble de phénomènes qualitativement différents qu'un Modèle d’Agents Macroeconomique (denoté MABM en anglais) peut générer, et qu'est-ce qui régit le passage d’un phénomène macroeconomique à un autre ?S'inspirant de la recherche en biophysique, l'idée centrale postule qu'il n'y a que quelques combinaisons critiques de paramètres qui déterminent un état spécifique du système (ou phase).En exploitant ces combinaisons avec un algorithme de gradient, steepest ascent ici, on peut efficacement découvrir l'ensemble de phénomènes différents qu'un MABM peut générer.L’intérêt de cette approche réside dans le fait qu’elle revele la révélation une structure plus simple que la complexité du MABM, ouvrant la voie à des politiques économiques efficaces qui se concentrent sur les directions pertinentes dans l’espace des paramètres.Cela suggère également que malgré la complexité d'un MABM et le nombre élevé de paramètres, l'ajustement de ces modèles ne nécessite que l'ajustement des directions pertinentes pour avoir un pouvoir prédictif.La première partie de cette thèse développe les méthodes derrière l'algorithme, mettant en évidence son efficacité sur les "Fourmis de Kirman", un modèle simple de comportement d’agents en interaction.L'algorithme est ensuite utilisé, et son efficacite demontrée, sur le MABM stylisé Mark-0 qui présente une phénoménologie riche avec un ensemble connu de phases macroscopiques. Je montre notamment comment nous pouvons récupérer les differentes phases malgré la complexité de la dynamique du modèle.La deuxième partie de cette thèse adopte en fait une approche inverse, intégrant des interactions intra-inter-agents dans des modèles macroéconomiques d'équilibre, dévoilant des phases émergentes et des crises endogènes.Ainsi, cette thèse explore le champ des ABMs, dévoilant leur potentiel dans la génération de différents scénarios qui peuvent être utilisés pour éclairer les décisions politiques dans des systèmes dynamiquement complexes
The economy, characterized by non-linearity, adaptability, and non-equilibrium dynamics, exhibits emergent phenomena, such as crises and inequalities, shaped by agents' reactions and policy interventions. Agent-based Modeling (ABM) is a recent modeling approach in macroeconomics that generates these phenomena from the ground up by simulating a multiplicity of heterogeneous interacting agents. While this method can generate emergent phenomena, it has often been critiqued as a black-box where causal mechanisms are unclear and there too vast set of generated dynamics. This thesis proposes a method to approach the fundamental question: What is the set of qualitatively different phenomena can an Macroeconomic Agent-based Model (MABM) generate, and what governs their transitions?Drawing on research in biophysics, the core idea posits that there are only a few critical parameter combinations that govern a specific outcome. Exploiting these with a gradient ascent algorithm, one can effectively uncover the set of different phenomena a MABM can recover. The significance of this approach lies in revealing a simpler structure beneath MABM complexity, paving the way for effective policies that address critical parameter directions. It also suggests that despite the complexity of an MABM and the high number of parameters, fitting these models requires only fitting critical directions to have predictive power.The first part of this thesis develops the methods behind the algorithm, highlighting its power on Kirman's Ants, a simple model of agent-herding. The algorithm is then demonstrated on the stylized Mark-0 MABM that has a rich phenomenology with a known set of phenomena. I show how we can recover this set of phenomena despite the complexity of the model's dynamics. The second part of this thesis actually adopts a reverse approach, embedding intra-agent interactions in equilibrium macroeconomic models, unveiling emergent phases and endogenous crises in these models. In its essence, this thesis navigates the intricate terrain of ABMs, unraveling their potential in generating different scenarios that can be used to inform policy decisions in dynamically complex systems

The goal of this thesis is to study the two key aspects of complexity of the financial system: interconnectedness and nonlinear relationships. In Chapter 1, I contribute to the literature that focuses on modelling the nonlinear relationship between variables at the extremes of their distribution. In particular, I study the nonlinear relationship between stock prices and short selling. Whereas most of the academic literature has focused on measuring the relationship between short selling and asset returns on average, in Chapter 1, I focus on studying the relationship that arises in the extremes of the two variables. I show that the association between financial stock prices and short selling can become extremely strong under exceptional circumstances, while at the same time being weak in normal times. The tail relationship is stronger for small cap firms, a result that is intuitively in line with the empirical findings that stocks with lower liquidity are more price-sensitive to short selling. Finally, results show that the adverse tail correlation between increases in short selling and declines in stock prices was not always lower during the ban periods, but had declined markedly towards the end of the analysis window. Such results cast doubts about the effectiveness of bans as a way to prevent self-reinforcing downward price spirals during the crisis. In Chapter 2, I propose a measure of interconnectedness that takes into account the time-varying nature of connections between financial institutions. Here, the parameters underlying comovement are allowed to evolve continually over time through permanent shifts at every period. The result is an extremely flexible measure of interconnectedness, which uncovers new dynamics of the US financial system and can be used to monitor financial stability for regulatory purposes. Various studies have combined statistical measures of association (e.g. correlation, Granger causality, tail dependence) with network techniques, in order to infer financial interconnectedness (Billio et al. 2012; Barigozzi and Brownlees, 2016; Hautsch et al. 2015). However, these standard statistical measures presuppose that the inferred relationships are time-invariant over the sample used for the estimation. To retrieve a dynamic measure of interconnectedness, the usual approach has been to divide the original sample period into multiple subsamples and calculate these statistical measures over rolling windows of data. I argue that this is potentially unsuitable if the system studied is time-varying. By relying on short subsamples, rolling windows lower the power of inference and induce dimensionality problems. Moreover, the rolling window approach is known to be susceptible to outliers because, in small subsamples, these have a larger impact on estimates (Zivot and Wang, 2006). On the other hand, choosing longer windows will lead to estimates that are less reactive to change, biasing results towards time-invariant connections. Thus, the rolling window approach requires the researcher to choose the window size, which involves a trade-off between precision and flexibility (Clark and McCracken, 2009). The choice of window size is critical and can lead to different results regarding interconnectedness. The major novelty of the framework is that I recover a network of financial spillovers that is entirely dynamic. To do so, I make the modelling assumption that the connection between any two institutions evolves smoothly through time. I consider this assumption reasonable for three main reasons. First, since connections are the result of many financial contracts, it seems natural that they evolve smoothly rather than abruptly. Second, the assumption implies that the best forecast of a connection in the future is the state of that connection today. This is consistent with the notion of forward-looking prices. Third, the assumption allows for high flexibility and for the data to speak for itself. The empirical results show that financial interconnectedness peaked around two main events: the Long-Term Capital Management crisis of 1998 and the great financial crisis of 2008. During these two events, I found that large banks and broker/dealers were among the most interconnected sectors and that real estate companies were the most vulnerable to financial spillovers. At the individual financial institution level, I found that Bear Stearns was the most vulnerable financial institution, however, it was not a major propagator, and this might explain why its default did not trigger a systemic crisis. Finally, I ranked financial institutions according to their interconnectedness and I found that rankings based on the time-varying approach were more stable than rankings based on other market-based measures (e.g. marginal expected short fall by Acharya et al. (2012) and Brownlees and Engle (2016)). This aspect is significant for policy makers because highly unstable rankings are unlikely to be useful to motivate policy action (Danielsson et al. 2015; Dungey et al. 2013). In Chapter 3, rather than assuming interconnectedness as an exogenous process that has to be inferred, as is done in Chapter 2, I model interconnectedness as an endogenous function of market dynamics. Here, I take interconnectedness as the realized correlation of asset returns. I seek to understand how short selling can induce higher interconnectedness by increasing the negative price pressure on pairs of stocks. It is well known that realized correlation varies continually through time and becomes higher during market events, such as the liquidation of large funds. Most studies model correlation as an exogenous stochastic process, as is done, for example, in Chapter 2. However, recent studies have proposed to interpret correlation as an endogenous function of the supply and demand of assets (Brunnermeier and Pedersen, 2005; Brunnermeier and Oehmke, 2014; Cont and Wagalath, 2013; Yang and Satchell, 2007). Following these studies, I analyse the relationship between short selling and correlation between assets. First, thanks to new data on public short selling disclosures for the United Kingdom, I connect stocks based on the number of common short sellers actively shorting them. I then analyse the relationship between common short selling and excess correlation of those stocks. To this end, I measure excess correlation as the monthly realized correlation of four-factor Fama and French (1993) and Carhart (1997) daily returns. I show that common short selling can predict one-month ahead excess correlation, controlling for similarities in size, book-to-market, momentum, and several other common characteristics. I verify the confirm the predictive ability of common short selling out-of-sample, which could prove useful for risk and portfolio managers attempting to forecast the future correlation of assets. Moreover, I showed that this predictive ability can be used to establish a trading strategy that yields positive cumulative returns over 12 months. In the second part of the chapter I concentrate on possible mechanisms that could give rise to this effect. I focus on three, non-exclusive, mechanisms. First, short selling can induce higher correlation in asset prices through the price-impact mechanism (Brunnermeier and Oehmke, 2014; Cont and Wagalath, 2013). According to this mechanism, short sellers can contribute to price declines by creating sell-order imbalances i.e. by increasing excess supply of an asset. Thus, short selling across several stocks should increase the realized correlation of those stocks. Second, common short selling can be associated with higher correlation if short sellers are acting as voluntary liquidity providers. According to this mechanisms, short sellers might act as liquidity providers in times of high buy-order imbalances (Diether et al. 2009b). In this cases, the low returns observed after short sales might be compensations to short sellers for providing liquidity. In a multi-asset setting, this mechanism would result in short selling being associated with higher correlation mechanism. Both above-mentioned mechanisms deliver a testable hypothesis that I verify. In particular, both mechanisms posit that the association between short selling and correlation should be stronger for stocks which are low on liquidity. For the first mechanism, the price impact effect should be stronger for illiquid stocks and stocks with low market depth. For the liquidity provision mechanism, the compensation for providing liquidity should be higher for illiquid stocks. The empirical results cannot confirm that uncovered association between short selling and correlation is stronger for illiquid stocks, thus not supporting the price-impact and liquidity provision hypothesis. I thus examine a third possible mechanism that could explain the uncovered association between short selling and correlation i.e. the informative trading mechanism. Short sellers have been found to be sophisticated market agents which can predict future returns (Dechow et al. 2001). If this is indeed the case, then short selling should be associated with higher future correlation. I found that informed common short selling i.e. common short selling that is linked to informative trading, was strongly associated to future excess correlation. This evidence supports the informative trading mechanism as an explanation for the association between short selling and correlation. In order to further verify this mechanism, I checked if informed short selling takes place in the data, whilst controlling for several of the determinants of short selling, including short selling costs. The results show evidence of both informed and momentum-based non-informed short selling taking place. Overall, the results have several policy implications for regulators. The results suggest that the relationship between short selling and future excess correlation is driven by informative short selling, thus confirming the sophistication of short sellers and their proven importance for market efficiency and price informativeness (Boehmer and Wu, 2013). On the other hand, I could not dismiss that also non-informative momentum-based short selling is taking place in the sample. The good news is that I did not find evidence of a potentially detrimental price-impact effect of common short selling for illiquid stock, which is the sort of predatory effect that regulators often fear.
Doctorat en Sciences économiques et de gestion
info:eu-repo/semantics/nonPublished

Nous nous proposons d'analyser le fonctionnement des coopératives agricoles définies comme le rassemblement d'un groupe d'individus afin de résoudre de façon solidaire leurs problèmes économiques. La coopérative est caractérisée par la dominance de phénomènes liés à communalité des décisions (de caractère cognitifs) et de la perception des flux d'information dans un cadre dynamique. L’objectif de cette recherche est d'obtenir une représentation, la plus fidèle possible, de la coopérative dans ses grandeurs essentielles. Jusqu’à présent les représentations, fondées sur une approche unique, ont du mal à capturer, de façon simultanée, les multiples dimensions de ce phénomène. C’est pourquoi, l'ensemble des activités de la coopérative est analysé simultanément à l'aide de trois approches que l'on cherche à intégrer: l'économie des conventions, la systémique, l'approche par la complexité. Les points de focalisation de cette recherche incluent: la coordination, la téléologie, l'information, la dynamique, l'auto-organisation, l'autonomie, la décision, l'ordre et le désordre, l'interaction, la modélisation, etc. Nous avons comme approches sous-jacentes: le constructivisme, la rationalité limitée, la rationalité procédurale, l'interdisciplinarité

Cette recherche-action est consacrée au développement durable appliqué au tourisme. Elle débute par l'analyse des textes fondamentaux pour connaître l'essence même de la durabilité. Elle se poursuit par l'analyse de la prise en compte du concept par les acteurs liés au tourisme. Elle se termine par des préconisations opérationnelles pour faciliter l'application du concept, en s'appuyant sur des expériences variées, menées au sein de territoires, d'entreprises et de formations. Cette recherche nous a semblé utile car nous sommes conscients de l'aggravation des problèmes environnementaux et sociaux de la planète, et de la part de responsabilité du tourisme. Nous avons observé, en 15 ans d'expériences, que des acteurs œuvrent en faveur de nouvelles formes de tourisme, moins prédatrices pour l'environnement, plus performantes socialement. Malheureusement ces initiatives sont souvent fragiles, marginales et marginalisées. Les raisons sont multiples. La plus fondamentale à nos yeux est le manque de savoir-faire pour qu'elles deviennent significatives. Celui-ci impose un changement de culture et de pratiques et l'application de valeurs universelles au service de la stimulation et de l'autonomie, dans une logique de coopération généralisée. L'économie n'est pas oubliée dans cette recherche. Aujourd'hui, le tourisme en France perd en compétitivité, en se basant sur des standards et des normes engendrant une concurrence effrénée entre les destinations et les entreprises. Il convient de changer de modèle pour favoriser une offre territorialement intégrée, diffuse, diversifiée, créative, inspirée, innovante, reposant sur des valeurs, une offre capable de répondre aux attentes des touristes et des citoyens.

Drawing on work in digital and algorithmic rhetoric, I analyze the organization of space and time in complexity models. I argue that the success of complexity economic models is a consequence of their ability to reflect the rhetorical situation of the marketplace: they represent time as a series of causal interactions and space as a consequence of coordinated interaction. Complexity economics investigates the inclination of markets to behave as complex systems: self-organizing, emergent, and non-linear. The 1999 Artificial Stock Market designed by Sante Fe Institute theorists Blake LeBaron, William Brian Arthur, and Richard Palmer is perhaps the fundamental expression of a complex marketplace. It was among the first models to accurately predict market downturns, a success that followed as a consequence of its construction. In ordinary market models, traders are driven by profit maximization and a simple recursive strategy: they remember their mistakes, and respond to analogous market situations with new information in a linear, causal process. In their model, LeBaron, Arthur, and Palmer created a series of overlapping causal processes in which the market could operate as a persuasive agent. In complexity economics, the market is itself an interlocutive agent, thereby permitting nonlinear, bidirectional causality. These causal modes have spatial and temporal corollaries. The unique compositions of complex economies is rhetorical. Their complex causal processes reflect a discursive marketplace in which space and time to emerge as relational properties.
Arts, Faculty of
English, Department of
Graduate

Les changements globaux induisent de grandes pressions sur les écosystèmes marins, leurbiodiversité et les pêcheries qui en dépendent. Dans ce contexte, de nombreux scientifiquesprônent l'utilisation de l'approche écosystémique pour la gestion de pêches (AEGP). Néanmoins,la manière d’opérationnaliser l’AEGP reste controversée. La thèse apporte des éclairages surl’opérationnalisation de cette dernière pour les pêcheries côtières tropicales.Pour ce faire, nous proposons un modèle de complexité intermédiaire (MICE) multi-espèces,multi-flottilles et multi-critères, prenant en compte les impacts des changements globaux. Lemodèle est calibré pour la pêcherie artisanale côtière guyanaise. A l'échelle guyanaise, leréchauffement climatique, l'augmentation de population humaine et les variations de surface dela mangrove sont considérés comme les déterminants majeurs du changement global. A partirdu modèle calibré, plusieurs stratégies de pêche et scénarios environnementaux sont comparésà long terme. Dans ce cadre, des premiers résultats publiés (chapitre 3) montrent le rôle négatifdu changement climatique à la fois sur la biodiversité marine et la production halieutique. Cestravaux mettent également en évidence le rôle majeur de la compétition entre espèces depoissons. Puis dans le chapitre 4 en comparant les résultats bio-économiques obtenus pourchaque stratégie de pêche, ces travaux mettent en lumière l’intérêt de stratégies d’éco-viabilitéen termes de durabilité et de réconciliation écologico-économique. Les derniers résultatsprésentés dans cette thèse, au chapitre 5, soulignent l’impact positif de la mangrove, bienqu’insuffisant pour compenser l’impact négatif du réchauffement climatique, sur la durabilitéécologico-économique de la pêche côtière. Au-delà de ces résultats, cette thèse apporte unesérie de contributions transversales importantes. En premier lieu, sur le plan méthodologique,ces travaux permettent d'exposer les avantages des MICE pour la mise en place de l’AEGP.Ensuite, en mettant en évidence les facteurs écologiques majeurs de l'écosystème avec d'unepart l'interaction de compétition et d'autre part les filtres environnementaux, les travauxéclairent les complexités écologiques nécessaires à l’AEGP. Enfin, en évaluant et comparant lesperformances écologico-économiques de différentes stratégies de pêche, ces travauxpermettent d'ébaucher des politiques publiques pour avancer vers la durabilité de la pêcheriecôtière guyanaise et vers l’AEGP face aux changements globaux
Global changes induce high pressure on marine ecosystems, biodiversity and fisheries. In thatregard many scientists advocate the use of an ecosystem-based fisheries management (EBFM).However, the operationalization of such an ecosystem-based approach remains challenging. Thisthesis gives insight into the operationalization of EBFM for tropical coastal fisheries. To achievethat we propose a multi-species, multi-fleet and multi-criteria model of intermediate complexity(MICE), taking into account the impacts of global changes. The model is calibrated for theGuyanese small-scale coastal fishery. At local scale, global warming, the increase of populationand the variations of mangrove surface are considered as the main drivers of global changes.From the calibrated model, several fishing management strategies and environmental scenariosare compared in the long-run. In this context, the first results published (chapter 3) show thedetrimental impact of climate change on both marine biodiversity and fishery production. Thispaper also highlights the major role of ecological competition between species. Then, in thechapter 4, by comparing the bio-economic results obtained under each fishing managementstrategy, this research demonstrates the interest of Ecoviability strategies in terms ofsustainability and ecologico-economic reconciliation. The last results displayed in this thesis, inchapter 5, underline the positive impact of mangrove on ecologico-economic sustainability of thecoastal fishery, even if it is insufficient to balance the negative impact of warming. Beyond theseresults, this thesis brings a series of important transverse contributions. First, methodologically,this research permits to show the benefits of MICE to operationalize EBFM. Then, by highlightingthe major ecological factors of the ecosystem with on the one hand the interaction ofcompetition and on the other hand the environmental filters, the work sheds light on theecological complexities necessary for the EBFM. Finally, by evaluating and comparing theecologico-economic performances of several fishing strategies, this research permits to outlinepolicy recommendations to move towards the sustainability of the Guyanese coastal fishery andtowards EBFM, in the face of global changes

Dans une première partie, nous étudions les bibliothèques académiques dont les principes fondateurs sont aujourd'hui interrogés par la société de l'information. Le gestionnaire d'une bibliothèque recherche la voie d'avancement la meilleure possible pour l'unité qu'il conduit. Les outils d'évaluation et de management utilisés en bibliothèque suscitente des insatisfactions car ils sont parfois inaptes à rendre compte de la nécessité d'une vision holistique de la bibliothèque. L'appproche constructiviste du management semble alors une alternative plausible pour aider les gestionnaires de biblithèques académiques à construire une vision stratégique de ces organisations. Nous bâtissons alors, dans une deuxième partie, un projet de modélisation basé sur la modélisation des systèmes complexes préconisée par Jean-Louis Le Moigne et sur la méthodologie des systèmes souples de Peter Checkland. Notre terrain de recherche est constitué de bibliothèques académiques françaises dans lesquelles nous effectuons interviews et observations participantes. Nous construisons un diagnostic en trois phases. La première phase permt au gestionnaire de visualiser l'offre de service dont nous montrons qu'elle est en évolution selon les trois axes des technologies, des moyens et des savoir-faire mise en oeuvre. La deuxième phase interroge le système informationnel de la bibliothèque, par une étude des environnements dans lequel l'organisation évolue et des flux qui la traversent. La troisième phase étudie le système décisionnel, s'intéressant à son organisation, à la circulation de l'information interne et aux processus de décision mis en oeuvre. Ce diagnostic en construction permanente est entendu dans la continuité du management de la bibliothèque et non comme une première étape d'une stratégie. Il est mis en oeuvre dans cinq bibliothèques. Les résultats montrent la richesse de l'apport de la modélisation, qui permet de proposer des modèles évolutifs, transposables et permettant l'apprentissage.

Petits, isolés, vulnérables, les territoires insulaires apparaissent comme les symboles des interrogations sur la soutenabilité des systèmes économiques. Cette coïncidence n’a rien de fortuite. Les expériences insulaires et coloniales occupent une place centrale dans la formation de l’économie politique, qui s’intéresse initialement tant à l’accroissement des richesses qu’à la pérennité de cette dynamique, notamment en raison des contraintes écologiques. Réciproquement, l’économie politique nourrit la formation d’un nouvel art de gouverner qui influence en profondeur les trajectoires insulaires et produit des rapports de pouvoir, qui persistent encore. Notamment à travers la notion de développement (durable) qui naturalise une lecture utilitariste de la soutenabilité. En rapprochant le paradigme de la complexité, l’économie écologique et les approches poststructuralistes, cette thèse propose d’explorer la construction de ce concept puis de le repenser dans un cadre institutionnaliste qui intègre pleinement les facteurs écologiques, symboliques et sociaux et la pluralité des formes d’organisation des économies. Elle étudie ensuite la construction et les ressorts de l’économie de plantation, à La Réunion et dans les Caraïbes, en interrogeant le paradoxe de l’ « insoutenabilité durable » : comment une économie fondée sur la destruction et incapable de satisfaire les finalités assignées en raison de ses contradictions, peut-elle se maintenir dans la longue durée ? Une troisième partie questionne la soutenabilité du projet départemental : décréter le développement, métamorphoser une colonie ruinée en une économie moderne, équilibrée, tirée par une croissance auto-entretenue
Small, isolated and vulnerable, islands have become symbols in current debates on the sustainability of economic systems. This is no coincidence. For colonial and insular experiences have played a key role in the emergence of political economy, which, initially focused on the creation of wealth as much as on its durability. Conversely, political economy nurtured the development of a new “art of government” which has deeply influenced islands trajectories and engendered new relations of power that persist today. In particular through the concept of (sustainable) development that naturalizes a contingent, utilitarian, view of sustainability. By bringing together the paradigm of complexity, ecological economics and poststructuralist works, this thesis aims to deconstruct this concept and reframe it through an institutionalist and interdisciplinary approach that fully integrates ecological, symbolic and social factors as well as the multiplicity of economies. It then studies the formation and evolution of plantation economies, both in Reunion Island and the Caribbean, to question the paradox of “durable unsustainability”: why and how can an economy grounded on destruction and unable to satisfy the ends it was designed for, maintain itself on the long term? A third part queries the sustainability of the “departementalisation” project, i.e. decreeing development: turning a ruined colony in a modern economy, able to reach European standards through self-sustained growth. It thus emphasizes the retroactions that wiped this utopia out to give birth to an original, yet fragile, model of resilient dependence

This thesis is concerned with the analysis of economic network formation. There are three novel sections to this thesis (Chapters 5, 6 and 8). In the first, the non-cooperative communication network formation model of Bala and Goyal (2000) (BG) is re-assessed under conditions of no inertia. It is found that the Strict Nash circle (or wheel) structure is still the equilibrium outcome for n = 3 under no inertia. However, a counter-example for n = 4 shows that with no inertia infinite cycles are possible, and hence the system does not converge. In fact, cycles are found to quickly dominate outcomes for n > 4 and further numerical simulations of conditions approximating no inertia (probability of updating > 0.8 to 1) indicate that cycles account for a dramatic slowing of convergence times. These results, together with the experimental evidence of Falk and Kosfeld (2003) (FK) motivate the second contribution of this thesis. A novel artificial agent model is constructed that allows for a vast strategy space (including the Best Response) and permits agents to learn from each other as was indicated by the FK results. After calibration, this model replicates many of the FK experimental results and finds that an externality exploiting ratio of benefits and costs (rather than the difference) combined with a simple altruism score is a good proxy for the human objective function. Furthermore, the inequity aversion results of FK are found to arise as an emergent property of the system. The third novel section of this thesis turns to the nature of network formation in a trust-based context. A modified Iterated Prisoners' Dilemma (IPD) model is developed which enables agents to play an additional and costly network forming action. Initially, canonical analytical results are obtained despite this modification under uniform (non-local) interactions. However, as agent network decisions are 'turned on' persistent cooperation is observed. Furthermore, in contrast to the vast majority of non-local, or static network models in the literature, it is found that a-periodic, complex dynamics result for the system in the long-run. Subsequent analysis of this regime indicates that the network dynamics have fingerprints of self-organized criticality (SOC). Whilst evidence for SOC is found in many physical systems, such dynamics have been seldom, if ever, reported in the strategic interaction literature.

The multidisciplinary approach to problem solving involves drawing appropriately from different viewpoints to redefine problems outside of normal boundaries and reach solutions based on a new understanding of complex situations. Social and economics science have always borrowed and embraced tools and instruments from mathematics and physics to develop their theories. Historically a real multidisciplinary methodology to economic and social issues has been neglected by the academic researchers due to a widespread gap in their formal approach. Recently a new interdisciplinary framework has been developed connecting together social and economics theories with the complex systems analysis; this approach reveals new conceptual prospectives and methodologies thanks to its multiple-level viewpoint, which are able to disclose novel challenges and problems. This thesis collects three different multidisciplinary approaches to social and economic behaviors formalized with the complex systems tools. Chapter 2: We introduce a statistical agent based model to describe the phenomenon of drug abuse and its dynamical evolution at the individual and global level. The agents are heterogeneous with respect to their intrinsic inclination to drugs, to their budget attitude and social environment. The various levels of drug use were inspired by the professional description of the phenomenon and this permits a direct comparison with all available data. We show that certain elements have a great importance to start the use of drugs, for example the rare events in the personal experiences which permit to overcome the barrier of drug use occasionally. The analysis of how the system reacts to perturbations is very important to understand its key elements and it provides strategies for effective policy making. The present model represents the first step of a realistic description of this phenomenon and can be easily generalized in various directions. Chapter 3: We characterize the statistical law according to which Italian primary school-size distributes. We find that the schoolsize can be approximated by a log-normal distribution, with a fat lower tail that collects a large number of very small schools. The upper tail of the school-size distribution decreases exponentially and the growth rates are distributed with a Laplace PDF. These distributions are similar to those observed for firms and are consistent with a Bose-Einstein preferential attachment process. The body of the distribution features a bimodal shape suggesting some source of heterogeneity in the school organization that we uncover by an indepth analysis of the relation between schools-size and citysize. We propose a novel cluster methodology and a new spatial interaction approach among schools which outline the variety of policies implemented in Italy. Different regional policies are also discussed shedding lights on the relation between policy and geographical features. Chapter 4: By analyzing the distribution of revenues across the production sectors of quoted firms we suggest a novel dimension that drives the firms diversification process at country level. Data show a non trivial macro regional clustering of the diversification process, which underlines the relevance of geopolitical environments in determining the microscopic dynamics of economic entities. These findings demonstrate the possibility of singling out in complex ecosystems those microfeatures that emerge at macro-levels, which could be of particular relevance for decision-makers in selecting the appropriate parameters to be acted upon in order to achieve desirable results. The understanding of this micro-macro information exchange is further deepened through the introduction of a simplified dynamic model.

Thesis (PhD)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: The primary concern of this dissertation will be to understand under what conditions novelty arises within a system. In classical philosophy, the notion of novelty is usually said to arise out of an event. However, the notion of an event often carries with it metaphysical and conservative implications. Therefore, part of the concern of this dissertation is to begin to develop an approach to novelty which is not dependent upon the event. This approach is developed through the insights offered by Critical Complexity and post‐structuralist philosophy. In social science the model of the frame has dominated how to think about the limitations to the context specific nature of knowledge. Instead of the analogy of a frame, this dissertation argues that it is better to adopt the notion of an ‘economy’. This is due to the fact that the notion of an economy allows social scientists to better theorize the relationships which constitute the models they create. The argument for an economy is made by exploring the connections between the work of Jacques Derrida, the complexity theorist Edgar Morin and Georges Bataille. However, when using the notion of an economy, one must always take the excess of this economy into consideration. This excess always feeds back to disrupt the economy from which it is excluded. Using terms developed in complexity theory, this dissertation illustrates how a system adapts to the environment by using this excess. Due to this there can never be a comprehensively modelled complex system because there are always facets of this system which remain hidden to the observer. The work of Alain Badiou, whose central concern is the notion of novelty arising out of an event, is introduced. The implications of depending on the event for novelty to arise are drawn out by discussing the affinities between the work of Derrida and Badiou. In this regard, Derrida’s use of the term ‘event’ much more readily agrees with a complexity informed understanding of the term in contrast to the quasi‐religious definition which Badiou uses. This complexity‐informed understanding of the event illustrates that what the event reveals is simultaneously a dearth and wealth of possibilities yet to be realized. Therefore the event cannot be depended upon to produce novelty. However, the notion of the event must not be discarded too quickly; classical science has traditionally discarded this idea due to its reductive approach. The idea of process opens up an understanding of the radical novelties produced in history to the possibility of the event and to a new understanding of ontology. This dissertation proposes that one can begin to think about radical forms of novelty without the event through the notion of experimentation. This approach allows one to engage with what exists rather than relying upon an event to produce novelty. This argument is made by following Bataille, who argues that through an engagement with non‐utilitarian forms of action, by expending for the sake of expenditure, the world is opened up to possibilities which remain unrealized under the current hegemony. In this light, this dissertation begins to develop a definition of novelty as that which forces a rereading of the system’s history.
AFRIKAANSE OPSOMMING: Hierdie proefskrif onderneem hoofsaaklik om die omstandighede waaronder nuwigheid binne ʼn stelsel ontstaan te verstaan. Daar word in die klassieke filosofie voorgehou dat nuwigheid gewoonlik vanuit ʼn gebeurtenis ontstaan. Die idee van ʼn gebeurtenis hou egter dikwels ongewenste metafisiese en konserwatiewe implikasies in. Hierdie proefskrif onderneem dus om, deels, ʼn benadering tot nuwigheid te ontwikkel wat onafhanklik van die gebeurtenis staan. Hierdie benadering word verder uitgebrei met behulp van insigte vanuit die Kritiese Kompleksiteits‐ en Post‐Strukturalistiese filosofie. Tot onlangs het die model van die raamwerk die wyse waarop daar oor die beperkinge van die konteks‐spesifieke aard van kennis in die sosiale wetenskappe gedink word oorheers. In hierdie proefskrif word voorgehou dat die idee van ʼn ‘ekonomie’ in plaas van die analogie van ʼn raamwerk hier gebruik behoort te word, omdat dit ons sal toelaat om die verhoudings binne die modelle wat deur sosiale wetenskaplikes gebruik word beter te verken. Verder word die moontlike verbande tussen Jacques Derrida , die kompleksiteitsfilosoof Edgar Morin en Georges Bataille teen hierdie agtergrond verken. Wanneer daar van ʼn ekonomie gepraat word, moet die oormaat van die ekonomie altyd in ag geneem word. Hierdie oormaat ontwrig altyd die ekonomie waarby dit uitgesluit word. Om te wys hoe die stelsel van so ʼn oormaat gebruik maak om by sy omgewing aan te pas, sal terminologie wat in die konteks van kompleksiteitsteorie ontwikkel is gebruik word. As gevolg van die oorvloed binne ʼn stelsel sal daar nooit ʼn volledige model van die stelsel ontwikkel kan word nie ‐‐ fasette van die stelsel sal altyd vir die waarnemer verborge bly. Verder sal die werk van Alain Badiou, wie se filosofie rondom die idee van nuwigheid wat uit ʼn gebeurtenis ontstaan gesentreed is, in hierdie verhandeling bespreek word. Die implikasies van die idee dat nuwigheid van die gebeurtenis afhanklik is word uitgelig deur die verwantskappe tussen die werke van Derrida en Badiou te bespreek. Derrida se gebruik van die term ‘gebeurtenis’ dra ʼn noue verwantskap met kompleksiteitsteorie, en dit word teenoor Badiou se amper‐godsdienstige gebruik van die term gestel. Daar word aangevoer dat daar binne ʼn kompleksiteits‐ingeligte verstaan van ʼn gebeurtenis beide ʼn skaarste en ʼn oorvloed van moontlikhede bestaan wat vervul kan word. Daarom kan daar juis nié op die gebeurtenis staatgemaak word om nuwigheid te skep nie. Die idee van die gebeurtenis moet egter nie te gou verwerp word nie. As gevolg van die klassieke wetenskap se reduksionisme is die idee van ʼn gebeurtenis tradisioneel ontken. Daarteenoor ontsluit die idee van ʼn proses die moontlikheid van radikale nuwighede in die geskiedenis as gevolg van ʼn verstaan van die gebeurtenis wat tot ʼn nuwe verstaan van die ontologie lei. Hierdie proefskrif stel dus voor dat ons voortaan aan radikale nuwigheid dink in terme van die denkbeeld van eksperimentering eerder as in terme van die gebeurtenis. Eksperimentering laat ons toe om te werk met wat ons het, eerder as om op ʼn gebeurtenis te moet wag. Na aanleiding van Bataille is die voorstel dat daar deur om te gaan met nieutilitaristiese vorms van optrede nuwe geleenthede vir die wêreld oopgemaak word; geleenthede wat onder die huidige hegemonie ongerealiseerd sal bly. In hierdie verband stel die proefskrif ʼn definisie van nuwigheid voor as dít wat mens dwing om die geskiedenis van ʼn stelsel te herformuleer.

Cette thèse en stratégie vise à comprendre comment les organisations pluralistes, qui combinent une pluralité de logiques d’action, peuvent conduire la transformation délibérée de leurs doctrines. Elle développe une approche originale du travail politico-stratégique dans les organisations pluralistes, approche qui s’appuie sur les théories pragmatistes de la rationalité et des institutions. Les résultats qu’elle présente sont issus d’une recherche de terrain (ethnographie et intervention) réalisée au sein d’une grande mutuelle d’assurance française, la Macif, qui est un acteur référent dans le champ de l’économie sociale. Le premier volet de la recherche a permis d’identifier et d’analyser les obstacles que rencontrent les organisations pluralistes lorsqu’elles cherchent à transformer leurs doctrines. Le second volet a permis de conceptualiser et d’expérimenter les modalités sous lesquelles elles peuvent parvenir à opérer la transformation souhaitée. La thèse présente pour finir un certain nombre de propositions visant à guider l’élaboration de la stratégie des organisations pluralistes
This doctoral research aims at understanding how pluralistic organizations that combine multiple institutional logics can engage in their deliberate transformation. It draws on pragmatist theories of rationality and of institutions to develop a novel perspective on strategy practices and processes in pluralistic organizations. Its results rely on fieldwork (ethnography and research-action) conducted within a French mutual insurance company, Macif, which is a key actor in the field of social economy. Firstly, this research identifies and analyzes the major obstacles that prevent pluralistic organizations from conducting such a transformation. Secondly, it conceptualizes and experiments ways to do so. Finally, this research suggests some methods for strategizing and organizing in pluralistic contexts

Il y a seulement une dizaine d’années que l’invariant de la complexité topologique a été défini. Il y a encore beaucoup de travail à y consacrer. Ici nous comparons algébriquement les deux invariants TC(X) et tc(X). En fait, ce qui nous motive, c’est la conjecture de leur égalité. Dans le but d’appuyer cette conjecture, nous regardons les bornes inférieures et supérieures de chacun, pour resserrer l’intervalle dans lequel ils se trouvent. Ceci nous a permis de trouver un nouveau résultat: la borne supérieure 2cat(X) de TC(X) est aussi une borne supérieure de tc(X). Ensuite, pour trois espaces nous avons calculé l’intervalle dans lequel se trouvent TC(X) et tc(X). Tous nos résultats nous incitent à dire que ces deux invariants se comportent bien de la même façon.

Italia e Corea del Sud: geograficamente e culturalmente così distanti ma sorprendentemente più simili di quel che si possa immaginare. A partire dall'analisi dello sviluppo dell'indice di complessità economico coreano, la tesi si vuole focalizzare su quali siano i fattori su cui l'Italia può prendere spunto per pianificare una ripresa economica decisa e convinta.

Le pilotage aux confins mouvants de la gouvernance. Économie, écologie, politique et régulation en Amazonie Colombienne, 1975-1990. Geert van Vliet, Paris I Panthéon-Sorbonne, Février 1997. Cette thèse se situe sur un terrain essentiellement théorique et méthodologique (essai de modélisation de la problématique de gouvernance) et analyse les possibilités de rétablir une capacité de pilotage (public) légitime dans des situations complexes et adverses extrêmes. A l'aide de diverses approches systémiques (l'apport de l'économie multidimensionelle, la gestion de l'environnement, les théories de régulation socio-politique et économique, et l'économie des organisations) nous caractérisons les éléments constitutifs du "terroir de la gouvernance" (première partie). Trois mécanismes vitaux de la gouvernance (régulation par la commande, par l'autonomie -et par sa variante- l'autopoièse) coexistent dans toute organisation. Ces mécanismes contribuent à la nature hétérogène des structures et des limites organisationnelles. Leur analyse permet, en mettant en évidence les paradoxes des processus d'apprentissage et d'innovation, d'expliquer l'efficacité décroissante des politiques publiques (deuxième partie). La caractérisation des systèmes de micro, macro et méga-régulation permet ensuite d'établir un lien entre les réflexions sur le thème de l'autonomie relative - et donc l'espace de ce qui peut être gouverné - avec celles sur les "confins" de cet espace, notamment en introduisant la théorie de l'autopoièse. En effet, pour les organisations autopoiètiques la notion "de limite" ne se pose pas, ce qui réduit sérieusement la validité des approches standard de pilotage stratégique. Ces réflexions alimentent une relecture de la situation de gouvernance en Amazonie Colombienne, où l'on distinguera trois périodes selon la prédominance de la régulation par la commande, l'autonomie ou l'autopoièse (troisième partie). En conclusion : la modélisation de la problématique de la gouvernance semble utile; par contre, il est difficile d'aller au delà de la phase de l'intelligibilité. Bien que quelques pistes soient proposées, la persistance des nombreux problèmes théoriques et méthodologiques signalés et l'existence de risques considérables associés à des tentatives de manipulation déplacées, constituent une invitation à la prudence. Gouverner aux confins exige un travail patient de la part de nombreux artisans, notamment à partir d'une meilleure connaissance des limites de nos propres systèmes de pilotage et d'organisation. MOTS-CLES SUGGÉRÉS : COMPLEXITE, AUTOPOIESE, AMAZONIE COLOMBIENNE, REGULATION, PILOTAGE STRATEGIQUE, GOUVERNANCE THEORIE DES SYSTEMES, THEORIE DES ORGANISATIONS, THEORIE DE LA NEGOCIATION, GESTION DE L'ENVIRONNEMENT, GESTION DE CONFLITS, ECONOMIE DES ORGANISATIONS, ECONOMIE MULTIDIMENSIONNELLE, GÉOPOLITIQUE

Dans cette thèse, nous abordons des problèmes de complexité structurelle, traitant de la classification des problèmes en fonction de leurs difficultés relatives, et nous nous intéressons aussi à l'existence d'une solution à un problème plus concret d'algorithmique en-ligne. Suivant cette dichotomie, dans la première partie de cette thèse nous étudions des problèmes de la classe des problèmes totaux TFNP, à savoir les problèmes de Sperner et la recherche de minimum local. Nous montrons les complétudes de problèmes de Sperner localement 2-dimensionnels dans les classes d'arguments de parité PPA, PPAD et PPADS. Nous améliorons ainsi des résultats de Papadimitriou et Grigni. Nous étudions ensuite le nombre de requêtes, au sens classique et au sens quantique, nécessaires pour résoudre un problème de Sperner en dimension arbitraire sur une pseudo-variété ; nous prouvons une borne inférieure ainsi qu'une borne supérieure correspondant à la complexité d'un algorithme, cette dernière étant optimale pour un cas précédemment étudié par Crescenzi et Silvestri. Enfin, nous donnons deux algorithmes, un classique et un quantique, pour déterminer la position d'un minimum local d'une fonction définie sur les sommets d'un graphe. Les analyses de nos deux algorithmes sont fondées sur l'existence de séparateurs de petite taille dans les graphes, et nous montrons un tel résultat qui améliore un résultat antérieur de Gilbert, Hutchinson et Tarjan. Dans la seconde partie de la thèse, nous nous intéressons à l'existence d'un algorithme en-ligne sans mémoire pour le problème CNN. Notre résultat généralise et améliore un résultat antérieur de Koutsoupias et Taylor
In this thesis, we treat problems of structural complexity, which aims at classifying problems depending on their relative difficulty to be solved, and we also study the existence of an efficient solution to a more concrete problem of online algorithmics. Following this dichotomy, in the first part of this thesis we study some problems of the class TFNP, more specifically Sperner problems and the search for a local minimum. We prove completeness of locally 2-dimensional Sperner problems in the ``Parity Argument'' classes PPA, PPAD and PPADS. Thus, we improve results of Papadimitriou and Grigni. We also study the number of queries, both in the classical and the quantum settings, necessary to solve an arbitrary dimensional Sperner problem on a pseudo-manifold ; we prove a lower bound and an upper bound corresponding to the complexity of an algorithm, the latter being optimal for a particular case previously studied by Crescenzi and Grigni. Finally, we give a classical and a quantum algorithm for spotting a local minimum of a function defined over the vertices of a graph, and prove that they use fewer queries than previously known algorithms on large classes of graphs. The analyses of our two algorithms rely on the use of {\em separator theorems}, and we prove such a theorem which slightly improves an older result of Gilbert, Hutchinson and Tarjan. In the second part of this thesis, we study the existence of a memoryless online algorithm for the CNN problem. Our results generalize and improve a previous result of Koutsoupias and Taylor

This thesis inquires into the nature of economy and its connection with the architecture of the house. Economy is a slippery term. In its original sense, the word had more to do with philosophy than finance. It raised issues of necessity, hierarchy, government, and happiness. Aristotle distinguished chrematistics, the art of getting wealth, from economy, the art of household management.Vitruvius, the first architectural theorist, offered a differing interpretation of the word, and included it as one of his six principles of architecture. Henry David Thoreau revisited Aristotleâ s ideas and invented a new, solitary economy. Both he and Aristotle emphasized that the purpose of economy is to meet material needs with sufficiency rather than surfeit. Economie House explores these ideas architecturally. On an imaginary site a perfect red cube sits on a concrete platform. Steel frames support a translucent, gabled roof. The cube opens in various ways to reveal the machines that serve manâ s biological needs. Closed, the cube suggests the limits of material goods as contributions to the good life.
Master of Architecture

Les recherches sur les erreurs de jugement en audit légal se sont surtout concentrées sur les causes provenant du manque d’indépendance de l’auditeur. Mais les travaux actuels s’accordent à avancer que ces erreurs sont également liées à la complexité de la tâche en audit (task complexity), cette complexité résultant des caractéristiques de l’auditeur (les facteurs subjectifs) ou de paramètres liés à la mission elle-même (les facteurs objectifs). Aussi, cette thèse propose-t-elle de démontrer que les facteurs objectifs expliquant la complexité de la tâche en audit légal ne sont pas à négliger, car ils provoquent aussi des erreurs de certification inévitables du fait de risques difficiles à évaluer, de l’instabilité du droit, de l’absence, de l’abondance ou de l’imprécision de règles comptables ou fiscales et de l’interprétation des normes d’exercice professionnel
Previous researches on judgmental errors during legal audit were focus on causes derived from the auditor’s lack of independence. But current works hold with the fact that these errors are also linked to task complexity audit, this complexity coming from auditor’s characteristics (subjective factors) or from the engagement’s parameters (objective factors). Thus, this thesis aims to demonstrate that objective factors explaining task complexity audit should not be neglected, as they also cause inevitable certification errors due to some risks hard to valuate, the instability of law, lack, abundance or imprecision of accounting or tax rules and the interpretation of French audit standards («Normes d’exercice professionnel»)

The Economic Complexity Index (ECI) is an indicator that can be used by countries with undiversified economies to measure the success of their efforts to grow and diversify their exports, in order to sustain their economic development. However, the index is distorted for countries with undiversified economies that are heavily dominated by a few sectors, such as the case of Saudi Arabia with its oil sector. This study leverages lessons from the economic development literature, and focuses on the export-oriented growth in East Asia, and investigates the role of industrial policies that guide and coordinate the government interventions and initiatives. The study applies lessons from the Economic Complexity framework to overcome the limitation in the Economic Complexity Index. The study then utilizes data analysis techniques to develop a modified ECI utilizing a population-adjusted version of the Revealed Comparative Advantage to normalize countries’ exports by their significance, and uses PageRank to capture the product space network information instead of the method of reflection used by ECI which is incompatible with the population-adjusted Revealed Comparative Advantage. The modified ECI can serve as a leading indicator that would allow tracking the success of the economic diversification efforts in countries whose economies are dominated by a few products or sectors, and thereby influence the development of their industrial policies.

Many real-world phenomena are characterized by complex structures. Modeling and detecting these architectures is of paramount importance to understand the dynamics of the considered systems and to consciously intervene on them. The COVID-19 pandemic is, in this sense, a telling example. One common feature of these complex structures is the heterogeneity of the node connectivity of the underlying network. This heterogeneity is one of the main culprits of the ongoing pandemic. In this thesis, we introduce a method capable of uncovering complex networks’ heterogeneous structures when finite-size effects hide the latter. Larger heterogeneity in the network structure leads to a smaller epidemic threshold. It is not a coincidence that policymakers worldwide are trying to reduce this heterogeneity (employing lockdowns and other less restrictive measurements) to stop the spread of the virus. We show that a macro-quarantine followed by a micro-quarantine can help in this direction. For this scope, we introduce an algorithm that is able to track super-spreaders. Notably, the same algorithm can be used to define an optimized strategy for vaccinations. Similarly to a virus, information continuously spreads on social networks. By combining Machine Learning and network theory techniques, we develop an algorithm able to discover what “social users” think about a particular topic—a sort of social listener, an AI alternative to traditional polls.

In the first part, we studies academic libraries whose founding principles are change with the information society. The library manager looks for the best ways to lead a library. Evaluation and management tools on libraries are sources of insatisfactions because of the lack of a holistic vision of libraries they give. Constructivist approaches of management seems an alternative way to help library managers in designing a strategic vision of these organizations. In the second part, we build a modelization project with complex systems modelization of Jean-Louis Le Moigne and soft systems methodology of Peter Checkland. French academic libraries constitute our research field in which we use participant observations and staff and managers interviews. Our system is made up of the academic library in the vision of it leader. We build a three phase diagnostic. With the first phase, the manager can observ services supply as a three axes system which evolves with technologies, materials and humans means and bibliotheconomic knowledge. The second phase studies the informational system with environmental and flow observations. The third phase studies the decisional system, looking for its organization, ist internal information circulation and its decisional processes. This diagnostic is in continuous construction. It works in the library management continuity and is not the first step of a strategic planning. We use the diagnostic in five libraries. Results show modelization supply with the creation of evolving, transposable and learning models.

O objetivo deste estudo foi o de investigar as oportunidades de aplicação da análise de complexidade como método de análise da Economia Mineral de um bem mineral, utilizando o níquel como estudo de caso. Para tanto foram estudadas as particularidades do mercado de commodities, com maior profundidade no caso do níquel, os fatores que nele influem e alguns modelos desenvolvidos para simulação, compreensão e predição do comportamento do sistema composto por este mercado. Foram verificadas as condições para que o mercado de bens minerais tenha sido considerado um sistema complexo. No caso do níquel foi também analisado o estado atual da tecnologia de extração, incluindo os desenvolvimentos mais recentes. Passou-se então à descrição do método utilizado na análise de complexidade que define a complexidade de um sistema como uma grandeza quantificável em função de sua topologia, representada pela estrutura das correlações entre suas variáveis, e da entropia total do sistema. A entropia total do sistema é a integração das entropias de Shannon das variáveis que participam de sua estrutura e é uma medida da sua incerteza. Neste método, o cálculo das correlações entre as variáveis não é feito estatisticamente, mas sim por meio do cálculo da entropia mútua. A vantagem deste método é que revela correlações entre pares de variáveis que apresentam relações não lineares ou até mesmo bifurcações, clustering e outras patologias de difícil tratamento estatístico. Desta forma, evita-se o termo correlação, que remete ao tratamento estatístico, preferindo-se acoplamento em seu lugar, para identificar a dependência entre duas variáveis. A seguir, foram abordadas as duas modalidades de análise de complexidade utilizadas: estática e dinâmica. A análise estática revela, por meio de um mapa cognitivo, a estrutura do sistema e as forças de acoplamento entre seus componentes, bem como os índices de complexidade, compostos das complexidades crítica, operacional e mínima, da entropia e da robustez. O índice de maior destaque é o da robustez, que mede a resiliência do sistema por meio da diferença entre as complexidades crítica e operacional, e é um indicador de sua sustentabilidade. A análise dinâmica revela, para sistemas que variam com o tempo, a evolução dos indicadores de complexidade ao longo do tempo. O interesse nesse tipo de análise é que o criador do método identificou experimentalmente que o colapso de um sistema é quase sempre precedido de um aumento brusco em sua complexidade. Esta característica é então explorada na análise do mercado do níquel para procurar antecipar crises. Na parte experimental pode-se então revelar a estrutura de acoplamentos de uma cesta de metais e do mercado específico do níquel, usando-se a análise estática. A seguir, passou-se a investigar a evolução dos indicadores de complexidade ao longo do tempo, tendo sido possível identificar as situações de crise no mercado pelo aumento de complexidade e entropia e, no caso específico da crise de 2008-2009 foi possível perceber o aumento significativo da complexidade e entropia antes mesmo da instalação da crise, fornecendo assim um aviso prévio do evento.
This study aimed at investigating the opportunities for application of complexity analysis as a method of analysis of mineral commodities economics, using nickel as case study. With that intention, the particularities of commodities were studied, in a deeper fashion in the case of nickel, its influencing factors and respective models which have been developed for simulating, understanding and predicting the behavior of the commodity market system. The conditions which allow the mineral commodities market to be considered a complex system have been verified. In the case of nickel the current state of the extraction technology including the latest developments has also been analyzed. Then focus goes to the description of the method used in complexity analysis, where complexity of a system is defined as a measurable quantity based on its topology, represented by the structure of the correlation between its variables, and the total entropy of the system. The total entropy of the system is the integration of the Shannon entropy of the variables that participate in its structure and is a measure of the systems uncertainty, i.e., its departure from a deterministic operating fashion. Calculation of correlations between variables in this method is not done statistically, but by calculating the mutual entropy between each pair of variables. The advantage of this method is that it reveals correlations between pairs of variables that exhibit nonlinear relationships or even bifurcations, clustering and other pathologies of difficult statistical treatment. Thus, the term correlation is avoided, which refers to the statistical treatment, being coupling the preferred expression to identify the dependence between two variables. The two types of complexity analysis were then performed: static and dynamic. Static analysis reveals the system structure and strength of couplings between the components by means of a cognitive map, as well as the complexity indices consisting of critical complexity, operational and minimum entropy and robustness. Robustness is the most interesting index in this case, as it measures the resilience of the system using the difference between the critical and operative complexities, and is an indicator of its sustainability. The dynamic analysis reveals, for time variant systems, the evolution of complexity indicators over time. Interest in this type of analysis is that the methods developer has experimentally identified that the collapse of a system is almost always preceded by a sharp increase in their complexity. This feature is then exploited in the analysis of the nickel market in trying to anticipate crises. Then, in the experimental section, structures of couplings were identified for a basket of metals and for the specific nickel market, using static analysis. Finally the evolution of indicators of complexity over time has been investigated, which revealed to be possible to identify a crisis in the market by the increasing complexity and entropy and, in the particular case of the 2008-2009 crisis its been also was possible to observe a significant increase in complexity and entropy just before installation of the crisis itself, providing a pre-alarm of the event.

Cette these a pour objet de demontrer qu'il est important de creer une strategie au coeur d'un territoire local afin d'agir sur les composants et les relations a l'interieur du systeme dans le but d'influer positivement sur les performances des firmes vis-a-vis du systeme economique mondial. En effet, cette these part du postulat suivant : les structures de production et l'environnement des firmes conditionnent la demarche internationale des entreprises et faconnent les performances mondiales du systeme local. La mondialisation des activites a entraine une destabilisation territoriale des firmes. Cette mondialisation a aussi contribue a reconsiderer les points d'ancrage des entreprises et a faire de l'environnement territorial un levier important de leur internationalisation. Ainsi, a travers le cas de la bretagne, cette these montre que le mouvement donne au systeme local devient de plus en plus le catalyseur de l'insertion internationale du territoire (ici la bretagne) et tout particulierement pour les p. M. E. . Le developpement du tissu economique territorial est stimule par une meilleure integration a l'activite mondiale. Cette integration peut se realiser de differentes manieres : par une capitalisation des entreprises, par une ouverture au commerce mondial ou par une presence directe internationale plus importante. Ainsi, face a l'evolution du mondial, la recherche de l'excellence des elements du territoire ainsi que l'etablissement de relations a l'interieur et a l'exterieur du territoire semblent deux conditions d'epanouissement du local. Il s'en trouvera d'autant plus dynamique que les structures de base et les relations seront regulees de maniere optimale
This thesis shows that it is important to create a strategy within the heart of a local region in order to be able to work with different components as well as individual relationships within a system so as to have a positive influence on the performance of local companies vis-a-vis the world economic system. This thesis begins with the following postulate: production structures an company environment condition the companies' international behaviour and mould the global performances within the regional system. The globalization of these actives has brought about a territorial destabilization of the firms. This globalization has also contributed towards the reconsideration of company cornerstones, and to use territorial environment as an important leverage internationalization. Therefore, using the case of brittany as an example, this thesis shows the trend given to the local system which has become an important "catalyst" for international territorial insertion (here in brittany), and especially for small an medium-sized companies based in this region. The development of the economic territorial fabric is stimulated by a better integration of world activity. This integration can be carried out in several ways : by the capitalization of the companies, by an opening towards world trade or by a larger and direct international presence. Faced with global evolution, the search of excellence of territorial principles as well as the establishment of internal an external relations of the area seem to be the two conditions for local fulfilment. It would be even more dynamic if the basic structures and relationships were more strongly controlled

This Doctoral Thesis unfolds into a collection of three distinct papers that share an interest in institutional theory and technology transfer. Taking into account that organizations are increasingly exposed to a multiplicity of demands and pressures, we aim to analyze what renders this situation of institutional complexity more or less difficult to manage for organizations, and what makes organizations more or less successful in responding to it. The three studies offer a novel contribution both theoretically and empirically. In particular, the first paper “The dimensions of organizational fields for understanding institutional complexity: A theoretical framework” is a theoretical contribution that tries to better understand the relationship between institutional complexity and fields by providing a framework. The second article “Beyond institutional complexity: The case of different organizational successes in confronting multiple institutional logics” is an empirical study which aims to explore the strategies that allow organizations facing multiple logics to respond more successfully to them. The third work “ How external support may mitigate the barriers to university-industry collaboration” is oriented towards practitioners and presents a case study about technology transfer in Italy.

This Doctoral Thesis unfolds into a collection of three distinct papers that share an interest in institutional theory and technology transfer. Taking into account that organizations are increasingly exposed to a multiplicity of demands and pressures, we aim to analyze what renders this situation of institutional complexity more or less difficult to manage for organizations, and what makes organizations more or less successful in responding to it. The three studies offer a novel contribution both theoretically and empirically. In particular, the first paper “The dimensions of organizational fields for understanding institutional complexity: A theoretical framework” is a theoretical contribution that tries to better understand the relationship between institutional complexity and fields by providing a framework. The second article “Beyond institutional complexity: The case of different organizational successes in confronting multiple institutional logics” is an empirical study which aims to explore the strategies that allow organizations facing multiple logics to respond more successfully to them. The third work “ How external support may mitigate the barriers to university-industry collaboration” is oriented towards practitioners and presents a case study about technology transfer in Italy.

Le concept de percolation a ete propose en 1956 par le mathematicien j. M. Hammersley. Il apporte une reponse aux limites des modeles economiques traditionnels qui peinent a expliquer le passage de l'individuel au collectif. Sur un reseau, la theorie de la percolation etudie a l'echelon global (macro) les effets d'actions locales (micro). D'une part, elle montre l'existence d'un seuil a partir duquel une modification qualitative de l'etat global du systeme se produit (amas percolant). D'autre part, elle etudie l'evolution de certaines grandeurs caracteristiques. La these propose l'analyse des phenomenes collectifs grace a des simulations numeriques de modeles de percolation qui integrent l'heterogeneite des comportements, l'alea des situations individuelles et les relations qu'entretiennent entre eux les elements d'un systeme. L'approche proposee considere que l'individuel et le collectif ne peuvent s'envisager l'un sans l'autre. Les concepts fondamentaux, puis les notions et les modeles plus avances sont presentes dans les deux premiers chapitres. Le troisieme expose des modeles socioeconomiques de comportements collectifs et de percolation. Enfin, le quatrieme chapitre presente de nouveaux apports de la percolation a la theorie economique, au travers des notions de dominance et d'integration de marche. La theorie de la percolation permet alors d'envisager et de comprendre des situations globales nouvelles.

Economie, puissance et connaissance sont les maitres-mots de cette these comment s'articulent l'économie et les formes du pouvoir social? La connaissance de l'économie est-elle possible hors des relations de pouvoir? Qu'est-ce que l'économie en soi? La thèse pose ces questions en termes historiques. L'auteur est un enqueteur, un "reporteur social". Les hasards professionnels le conduisirent dans d'autres champs que celui de la science economique. Mais la theorie de la valeur est le fil directeur de ses travaux. La thè́se affirme l'inconsistance epistémologique d'une théorie purement économique de la valeur. La théorie de la valeur ne se réduit pas à une théorie de l'équilibre général: elle suppose une théorie politique du pouvoir ici, "politique" ne désigne pas une structure specifique du champ social, à côté de l'economique, de l'idéologique etc. , Mais une fonction souveraine qui unifie la société et mobilise toutes ses fonctions spécialisées. Cette fonction de puissance ne se révèle que dans le champ mondial, et non à l'interieur d'un etat-nation ou d'une societe abstraite vus isolement. La thèse reconsidère l'histoire de la pensée économique de John Hales à Adam Smith qui, le premier, élimina le pouvoir de la réflexion économique. Elle analyse aussi la genèse des concepts de la comptabilite nationale moderne. Elle se situe donc à la croisée de l'histoire, de la science politique et de la science économique au sens propre.

Deux objectifs a notre etude : comparer l'efficacite des methodes pour mesurer l'impact economique et social du secteur spatial et fournir sur cet impact des donnees fiables. Le champ d'application retenu est le canada. Mais en raison de l'interdependance des principaux pays ayant une activite dans le secteur spatial, et surtout de l'experience americaine et europeenne dans ce domaine, les methodes utilisees par ces deux groupes de pays seront analysees. Le chapitre un englobe une presentation generale de l'industrie spatiale ainsi que des principales particularites propres a l'industrie spatiale canadienne. Ce chapitre un met l'accent sur les conditions de creation des structures, leur evolution et leur transformation. Le chapitre deux presente les modeles macroeconomiques utilises notamment pour determiner l'impact indirect du secteur spatial sur l'economie. Ces modeles sont bases sur l'integration de la variable recherche et developpement dans la fonction de production. Le chapitre trois replace la variable rd utilisee par les modeles macroeconomiques dans le processus d'innovation et de diffusion. Les modeles microeconomiques ont pour objectif de determiner la rentabilite de l'output de rd : les innovations et leur diffusion. Ils permettent egalement de differencier entre rentabilite privee et rentabilite sociale des innovations. Les deux chapitres macroeconomiques et microeconomiques s'attachent a montrer l'existence d'un impact positif de la recherche-developpement spatiale (chapitre deux), et a en identifier les principales variables explicatives (chapitre trois). Le chapitre quatre a pour objectif d'identifier et de quantifier les benefices economiques et sociaux des deux grands programmes canadiens (les satellites de telecommunication m-sat et les satellites de teledetection radarsat) et de presenter la prochaine etape dans les applications spatiales (station orbitale)
Two objectives motivate our study : comparing the efficiency of methods to measure the economic and social impact of the space sector and providing reliable data on this impact. The investigating field is canada. But, taking into account the interdependence of the leading countries in the space sector, and moreover the american experience, the methods used by these two groups will be analysed. The first chapter presents the space industry in general, with the main particularities of the canadian space industry. This chapter put the emphasis on the determinants of the creation, evolution and transformation of the structures. The second chapter deals with the macroeconomics models used mainly to measure the indirect impact of the space sector on the economy. These models are based on the integration of the variable research and development (rd) in the production function. The third chapter replaces the variable research and development used in the macroeconomics models in the process of innovation and diffusion. It also allos to differentiate between private return and social return of innovations. These two chapters - macroeconomics and microeconomics - show the exis- tence of a positive impact of the space research and development (chapter 2) and identify the main explicative variable (chapter 3). The fourth chapter intends to identify and quantify the economic and social benefit of two majors canadian space programs (m-sat and radarsat) and presents the next step in space applications : the orbital stations

Global Value Chains (GVCs) emerged in the last decades and changed the landscape of the international organisation of production. Thanks to the reduction of transport costs and to the development of new technologies the production process increasingly fragmented into single phases carried out by different firms, also located in different countries. This led to the birth of a dense international network of production with multiple commercial and financial linkages between firms and countries. Such a complex architecture offers remarkable advantages, such as reduced procurement costs and high degrees of local/regional specialization, but also exposes to relevant risks and sources of instability, especially in the presence of unexpected shocks. For this reason, the international production network and GVCs emerged as an important topic in the international economic literature. In this globalization process, developed countries have so far had a central role: they have the highest shares of GVCs participation, extract the largest part of value added, and are positioned in the most profitable segments of the chains. However, GVCs may offer remarkable opportunities also for developing countries (Taglioni and Winkler 2016; World Bank 2019, 2020). This project focuses on the role that GVCs may have in the development process of North Africa. This area is trying to emerge from the group of middle income countries and enter a stable development path. However, the financial crisis of 2008 and the series of Arab Spring revolutions have undermined the progresses achieved over the past decades. In this scenario, the COVID-19 pandemic poses further serious concerns. Addressing economic development for the whole area is complex. Despite having suffered common shocks as well as sharing many demographic, cultural and social characteristics, the economic structure of these countries is different. Algeria and Libya are highly dependent on revenues from raw materials such as oil and natural gas; Morocco and Tunisia have developed over the years an advanced manufacturing fabric thanks also to the entry of foreign multinationals into domestic economy; finally, Egypt has an economic structure where traditional sectors, such as shipbuilding and agriculture, coexist along with advanced ones such as ICT. In light also of this diversity, my research is structured as a series of self-contained chapters focused on the analysis of specific issues concerning the role of GVCs on development. In particular, in the first chapter I address the impact of GVCs participation on firm productivity. The issue has been widely discussed in the literature: while first studies pointed out the existence of just a self-selection mechanism into international markets according to productivity, evidence came out about a learning by participating effect. The chapter enriches this literature by investigating Egyptian firms’ performances in the aftermath of the Arab Spring revolution. I find a positive and significant impact of GVCs participation on firm productivity, especially for domestic firms. In the second chapter, I investigate the relationship between firm GVCs participation and FDI activity using French administrative data. Relying on a very recent strand of literature, I hypothesise and prove that the direction of FDI follows and is caused by firm pattern of trade. Introducing governance indicators, I find changes in the general relationship according to countries' development. Moreover, a focus on NA reveals the peculiarity of this area. Finally, in the last chapter, I link the literature on GVCs with the Economic Complexity (EC) approach (Hidalgo et al., 2007; Hidalgo and Hausmann, 2009). The latter provides new tools and metrics to measure countries economic performances and offers interesting insights to study economic development. I link these strands of literature by applying the Product Space and other EC metrics to the study of GVCs. I also provide a new index to measure countries GVCs participation coherent with the EC approach. These contributions are then applied to the case study of NA countries. All in all, the research proves the importance of internationalisation for economic development. Integrating into GVCs, firms may increase their performances, and therefore countries improve their position and widen their linkages into the international production network.

Global Value Chains (GVCs) emerged in the last decades and changed the landscape of the international organisation of production. Thanks to the reduction of transport costs and to the development of new technologies the production process increasingly fragmented into single phases carried out by different firms, also located in different countries. This led to the birth of a dense international network of production with multiple commercial and financial linkages between firms and countries. Such a complex architecture offers remarkable advantages, such as reduced procurement costs and high degrees of local/regional specialization, but also exposes to relevant risks and sources of instability, especially in the presence of unexpected shocks. For this reason, the international production network and GVCs emerged as an important topic in the international economic literature. In this globalization process, developed countries have so far had a central role: they have the highest shares of GVCs participation, extract the largest part of value added, and are positioned in the most profitable segments of the chains. However, GVCs may offer remarkable opportunities also for developing countries (Taglioni and Winkler 2016; World Bank 2019, 2020). This project focuses on the role that GVCs may have in the development process of North Africa. This area is trying to emerge from the group of middle income countries and enter a stable development path. However, the financial crisis of 2008 and the series of Arab Spring revolutions have undermined the progresses achieved over the past decades. In this scenario, the COVID-19 pandemic poses further serious concerns. Addressing economic development for the whole area is complex. Despite having suffered common shocks as well as sharing many demographic, cultural and social characteristics, the economic structure of these countries is different. Algeria and Libya are highly dependent on revenues from raw materials such as oil and natural gas; Morocco and Tunisia have developed over the years an advanced manufacturing fabric thanks also to the entry of foreign multinationals into domestic economy; finally, Egypt has an economic structure where traditional sectors, such as shipbuilding and agriculture, coexist along with advanced ones such as ICT. In light also of this diversity, my research is structured as a series of self-contained chapters focused on the analysis of specific issues concerning the role of GVCs on development. In particular, in the first chapter I address the impact of GVCs participation on firm productivity. The issue has been widely discussed in the literature: while first studies pointed out the existence of just a self-selection mechanism into international markets according to productivity, evidence came out about a learning by participating effect. The chapter enriches this literature by investigating Egyptian firms’ performances in the aftermath of the Arab Spring revolution. I find a positive and significant impact of GVCs participation on firm productivity, especially for domestic firms. In the second chapter, I investigate the relationship between firm GVCs participation and FDI activity using French administrative data. Relying on a very recent strand of literature, I hypothesise and prove that the direction of FDI follows and is caused by firm pattern of trade. Introducing governance indicators, I find changes in the general relationship according to countries' development. Moreover, a focus on NA reveals the peculiarity of this area. Finally, in the last chapter, I link the literature on GVCs with the Economic Complexity (EC) approach (Hidalgo et al., 2007; Hidalgo and Hausmann, 2009). The latter provides new tools and metrics to measure countries economic performances and offers interesting insights to study economic development. I link these strands of literature by applying the Product Space and other EC metrics to the study of GVCs. I also provide a new index to measure countries GVCs participation coherent with the EC approach. These contributions are then applied to the case study of NA countries. All in all, the research proves the importance of internationalisation for economic development. Integrating into GVCs, firms may increase their performances, and therefore countries improve their position and widen their linkages into the international production network.

Sebbene le regioni (territori che ospitano comunità integrate di abitanti, attività economiche ed istituzioni) siano diventati attori fondamentali dell'economia internazionale, le scienze economiche non sono ancora in grado di fornire un modello capace di interpretare le dinamiche economiche e fornire supporto alle politiche. Il motivo di questo limite è che gli approcci tradizionali non riescono a modellizare la complessità che caratterizza le economie regionali. Il progetto di ricerca si è dunque posto l'obiettivo di discutere tale complessità e verificare la possibilità di fornire un controfattuale. L'analisi ha tenuto in conto l'eterogeneità degli agenti e l'effetto di shock esogeni. Inoltre si è discusso come, a causa della complessità, i policy-makers siano confrontati alla difficoltà di predisporre politiche capaci di anticipare gli shock endogeni ed esogeni. I risultati teorici sono stati utilizzati, in parte, per analizzare la regione metropolitana di Madrid. In particolare si è analizzata la capacità locale di riprodurre una dinamica di crescita. I risultati indicano che anche regioni che attraversano cicli positivi hanno la necessità di ottimizzare l'utilizzo dei fattori di produzione e specializzare la propria economia in settori sostenuti dalla domanda internazionale. Una eccessiva specializzazione in settori non-tradable può, infatti, mettere in discussione la sostenibilità della crescita.
Regions (territories hosting integrated communities of citizens, firms, and institutions) have become key actors within the International economy, yet conventional economics cannot provide a model to explain local dynamics and to support policy-making. Such limit is due to complexity characterizing regional economies. Therefore, the present research aims at assessing complexity in regions and verifying the possibility of modelling regional economies. to assess regional economies, The research takes into account heterogeneity of agents as well as exogenous shocks. Moreover the research focuses on the effect of complexity on policy-making. Because of complexity, to be effective, regional policy has to take into account local and external shocks. Such theoretical background is partly used to assess the metropolitan region of Madrid. The empirical analysis shows that even a successful region can be challenged by the sustainability of economic growth. To enhance its international competitiveness, the region has to improve the use of local factors of production and to increase its specialization in sectors that are traded on the international market. An excessive specialization in non-tradable goods may, in fact, challenge growth sustainability.

Sebbene le regioni (territori che ospitano comunità integrate di abitanti, attività economiche ed istituzioni) siano diventati attori fondamentali dell'economia internazionale, le scienze economiche non sono ancora in grado di fornire un modello capace di interpretare le dinamiche economiche e fornire supporto alle politiche. Il motivo di questo limite è che gli approcci tradizionali non riescono a modellizare la complessità che caratterizza le economie regionali. Il progetto di ricerca si è dunque posto l'obiettivo di discutere tale complessità e verificare la possibilità di fornire un controfattuale. L'analisi ha tenuto in conto l'eterogeneità degli agenti e l'effetto di shock esogeni. Inoltre si è discusso come, a causa della complessità, i policy-makers siano confrontati alla difficoltà di predisporre politiche capaci di anticipare gli shock endogeni ed esogeni. I risultati teorici sono stati utilizzati, in parte, per analizzare la regione metropolitana di Madrid. In particolare si è analizzata la capacità locale di riprodurre una dinamica di crescita. I risultati indicano che anche regioni che attraversano cicli positivi hanno la necessità di ottimizzare l'utilizzo dei fattori di produzione e specializzare la propria economia in settori sostenuti dalla domanda internazionale. Una eccessiva specializzazione in settori non-tradable può, infatti, mettere in discussione la sostenibilità della crescita.
Regions (territories hosting integrated communities of citizens, firms, and institutions) have become key actors within the International economy, yet conventional economics cannot provide a model to explain local dynamics and to support policy-making. Such limit is due to complexity characterizing regional economies. Therefore, the present research aims at assessing complexity in regions and verifying the possibility of modelling regional economies. to assess regional economies, The research takes into account heterogeneity of agents as well as exogenous shocks. Moreover the research focuses on the effect of complexity on policy-making. Because of complexity, to be effective, regional policy has to take into account local and external shocks. Such theoretical background is partly used to assess the metropolitan region of Madrid. The empirical analysis shows that even a successful region can be challenged by the sustainability of economic growth. To enhance its international competitiveness, the region has to improve the use of local factors of production and to increase its specialization in sectors that are traded on the international market. An excessive specialization in non-tradable goods may, in fact, challenge growth sustainability.

On montre que dans une suite u minimale obtenue par substitution injective uniforme, tout mot lu dans u et de longueur assez longue admet une factorisation unique. Ce resultat permet de reconnaitre par un automate l'application qui a n associe p de n plus un, moins p de n, ou p de n designe le nombre de mots lus dans u, de longueur n

Le sujet de cette thèse est la complexité métrique, au sens de Kolmogorov-Jean, de courbes horizontales pour une métrique sous-Riemannienne générique de co-rang un, qui est définie sur une variété de dimension N. On établit le problème dans le cadre du problème de planification de trajectoires. Premièrement, pour N plus grand ou égal à 4, en utilisant principalement des formes normales pour des structures sous-Riemanniennes de contact et quasi-contact, on donne explicitement des expressions pour la complexité métrique en termes des invariants élémentaires du problème. Dans le cas N=3, lequel est le plus compliqué s' il y a des points de Martinet, on ne donne que des bornes pour la complexité métrique. Deuxièmement, on construit la synthèse optimale asymptotique du problème de planification de trajectoires. Dans un troisième temps on présente quelques algorithmes qui donnent une solution au problème de planification de trajectoires, et leur mise en oeuvre au modèle de l'uni-cycle
The subject of this thesis is the metric complexity in the sense of Kolmogorov-Jean for horizontals curves of generic sub-Riemannian metrics of co-rank one, defined on a manifold of dimension N. We set the problem in the context of the motion planning problem. At the first place, for N bigger than 3, by aking use of the normal forms for the contact and quasi-contact sub-Riemannian structures, we provide explicit expressions for the metric complexity in terms of elementary invariants of the problem. The case N equal 3, turns out to be the more complicated, and in this case, in the presence of Martinet points, we provide bounds for the metric complexity. Secondly, we construct the asymptotic optimal syntheses for the motion planning problem. At the end, we present some algorithms that solve the motion planning problem and their corresponding implementation for the model of the unicycle

Considérer le jeu comme un acte, c’est lui prêter une intention et une finalité. Sa problématique est donc moins son identification en tant que jeu, évidente à chacun, que la communication de l’idée de ce qui se joue : « Qu’est-ce donc que le jeu ? Si personne ne me demande, je le sais ; mais que je veuille l’expliquer quand on me demande, et je ne sais plus. » (L. Wittgenstein). Plus que le jeu, c’est son discours qui est l’objet de notre étude, c’est-à-dire cette dynamique qui implique l’acte de jouer et fait de l’homme un joueur, et qui se situe dans l’aire intermédiaire d’expérience (D. Winnicott). Un discours à l’interface du discours de l’homme sur le jeu et du discours du jeu sur l’homme, autrement dit un discours du ludique : une ludologie. Approcher le jeu tel qu’il se dit, depuis l’implicite de la mythologie à l’explicite de la littérature ou de la pensée épistémique du jeu, c’est mettre l’accent sur les valeurs qu’il véhicule et par lesquelles on le reconnaît, puisque le jeu n’est pas une forme mais une modalisation : « ce qui pour nous est en train de se passer » (E. Goffman).A partir des fonctions du jeu, il est possible d’organiser le discours du ludique et de dépasser ainsi le simple champ d’étude pour mettre en place un cadre de compréhension ludologique. Ce cadre n’est pas plus la sélection d’un discours par rapport à un autre que la création d’un nouveau discours, mais bien l’articulation des discours du jeu et sur le jeu, pour dégager moins des éléments constitutifs que la cohérence de leur dialogue (S. Genvo), reflet de la dynamique du jeu qu’est le ludique. En effet, dans une perspective complexe (E. Morin), tous ces discours du jeu se contredisent moins qu’ils ne se complètent et se fécondent, à condition de les envisager potentiellement, c’est-à-dire dans ce que chacun est susceptible de « dire » des autres. En tant que discours du discours du jeu, la ludologie est donc l’homothétique de celui-ci, à l’interface de l’homme et de son jeu, de la narration et de la simulation, du temps et de l’espace où la potentialité qu’ouvre le jeu à l’homme se réalise dans le choix qui n’appartient ni tout à fait à l’un ni tout à fait à l’autre, mais dont l’interaction rend enfin possible « l’exercice d[es] possible[s] » (J. Henriot), offrant au jeu, par l’accomplissement de l’homme, sa condition comme sa finalité : son caractère ludique en tant que synonyme de plaisir.Ainsi, en entreprenant le jeu humain d’un point de vue communicationnel et sémiotique, il est possible d’en dégager la spécificité et la portée qu’incarne le ludique, et plus encore du discours de celui-ci qu’est la ludologie en tant que mode de connaissance prospectif, projectif, créatif et expérientiel à même d’enrichir les sciences humaines et sociales
Considering play as an act is assigning it intent and purpose. Its problem is less its identification as play, obvious to everyone, that a problem of communicating the idea of what is being played: « So, what is play ? If no one asks me, I know; but if I want to explain when people ask me, I do not know anymore. » (L. Wittgenstein). More than play, this is a rethoric which is the topic of our research, that is to say this dynamics that involves the act of playing and makes human a player belongs to the intermediate area of experience (D. Winnicott). A rethoric at the interface between human rethoric of play and play rethoric about human, a playful rethoric of the ludic way : a ludology.Approaching play as it express itself, from implicit to explicit, from mythology to literature or epistemic thought about play, leads to focus on the values that play conveys and through it can be recognized, since play is not a form but a modalization: « what we believe is happening » (E. Goffman).From the functions of play, it is possible to organize the playful rethoric and, beyond the simple field of study, to develop a framework of ludologic understanding. This framework no more favours a rethoric over another nor the creation of a new rethoric, but definitely the articulation of the rethorics of play, not emphasizing components but the consistency of their dialogue (S. Genvo), consequence of the dynamics of the ludic way. Indeed, from a complex perspective (E. Morin), all theses rethorics of play do not contradict but complement and fertilize each other, provided we consider them potentially, for what each is likely to point out from the other.As rethoric of play rethoric, ludology is its homothetic, at the interface of human and his play, narration and simulation, time and space where the potentiality that play opens to human is realized in the choice that does not belong entirely to one or to the other, but whose interaction finally makes possible « the exercise of possibilities » (J. Henriot), providing the play, with the accomplishment of human, its condition as its purpose: its playful feature as synonymous with fun.So, undertaking play from a communicational and semiotic point of view makes possible to identify the specificity and scope of human play that embodies the ludic way. Ludology is this rethoric of the rethoric of play as a prospective, projective, creative and experiential way of knowledge that enriches human and social sciences

Considérer le jeu comme un acte, c’est lui prêter une intention et une finalité. Sa problématique est donc moins son identification en tant que jeu, évidente à chacun, que la communication de l’idée de ce qui se joue : « Qu’est-ce donc que le jeu ? Si personne ne me demande, je le sais ; mais que je veuille l’expliquer quand on me demande, et je ne sais plus. » (L. Wittgenstein). Plus que le jeu, c’est son discours qui est l’objet de notre étude, c’est-à-dire cette dynamique qui implique l’acte de jouer et fait de l’homme un joueur, et qui se situe dans l’aire intermédiaire d’expérience (D. Winnicott). Un discours à l’interface du discours de l’homme sur le jeu et du discours du jeu sur l’homme, autrement dit un discours du ludique : une ludologie. Approcher le jeu tel qu’il se dit, depuis l’implicite de la mythologie à l’explicite de la littérature ou de la pensée épistémique du jeu, c’est mettre l’accent sur les valeurs qu’il véhicule et par lesquelles on le reconnaît, puisque le jeu n’est pas une forme mais une modalisation : « ce qui pour nous est en train de se passer » (E. Goffman).A partir des fonctions du jeu, il est possible d’organiser le discours du ludique et de dépasser ainsi le simple champ d’étude pour mettre en place un cadre de compréhension ludologique. Ce cadre n’est pas plus la sélection d’un discours par rapport à un autre que la création d’un nouveau discours, mais bien l’articulation des discours du jeu et sur le jeu, pour dégager moins des éléments constitutifs que la cohérence de leur dialogue (S. Genvo), reflet de la dynamique du jeu qu’est le ludique. En effet, dans une perspective complexe (E. Morin), tous ces discours du jeu se contredisent moins qu’ils ne se complètent et se fécondent, à condition de les envisager potentiellement, c’est-à-dire dans ce que chacun est susceptible de « dire » des autres. En tant que discours du discours du jeu, la ludologie est donc l’homothétique de celui-ci, à l’interface de l’homme et de son jeu, de la narration et de la simulation, du temps et de l’espace où la potentialité qu’ouvre le jeu à l’homme se réalise dans le choix qui n’appartient ni tout à fait à l’un ni tout à fait à l’autre, mais dont l’interaction rend enfin possible « l’exercice d[es] possible[s] » (J. Henriot), offrant au jeu, par l’accomplissement de l’homme, sa condition comme sa finalité : son caractère ludique en tant que synonyme de plaisir.Ainsi, en entreprenant le jeu humain d’un point de vue communicationnel et sémiotique, il est possible d’en dégager la spécificité et la portée qu’incarne le ludique, et plus encore du discours de celui-ci qu’est la ludologie en tant que mode de connaissance prospectif, projectif, créatif et expérientiel à même d’enrichir les sciences humaines et sociales
Considering play as an act is assigning it intent and purpose. Its problem is less its identification as play, obvious to everyone, that a problem of communicating the idea of what is being played: « So, what is play ? If no one asks me, I know; but if I want to explain when people ask me, I do not know anymore. » (L. Wittgenstein). More than play, this is a rethoric which is the topic of our research, that is to say this dynamics that involves the act of playing and makes human a player belongs to the intermediate area of experience (D. Winnicott). A rethoric at the interface between human rethoric of play and play rethoric about human, a playful rethoric of the ludic way : a ludology.Approaching play as it express itself, from implicit to explicit, from mythology to literature or epistemic thought about play, leads to focus on the values that play conveys and through it can be recognized, since play is not a form but a modalization: « what we believe is happening » (E. Goffman).From the functions of play, it is possible to organize the playful rethoric and, beyond the simple field of study, to develop a framework of ludologic understanding. This framework no more favours a rethoric over another nor the creation of a new rethoric, but definitely the articulation of the rethorics of play, not emphasizing components but the consistency of their dialogue (S. Genvo), consequence of the dynamics of the ludic way. Indeed, from a complex perspective (E. Morin), all theses rethorics of play do not contradict but complement and fertilize each other, provided we consider them potentially, for what each is likely to point out from the other.As rethoric of play rethoric, ludology is its homothetic, at the interface of human and his play, narration and simulation, time and space where the potentiality that play opens to human is realized in the choice that does not belong entirely to one or to the other, but whose interaction finally makes possible « the exercise of possibilities » (J. Henriot), providing the play, with the accomplishment of human, its condition as its purpose: its playful feature as synonymous with fun.So, undertaking play from a communicational and semiotic point of view makes possible to identify the specificity and scope of human play that embodies the ludic way. Ludology is this rethoric of the rethoric of play as a prospective, projective, creative and experiential way of knowledge that enriches human and social sciences

The central issue of this paper is that social complexity in South Andean hunter-gatherers is related to an emergent process of regional economic intensification that began in the Middle Holocene period. This process involved a strategy of economic specialization in the use of wild camelids, followed by a diversifying strategy related to the domestication of plants and animals, and the subsequent establishment of long-distance exchange networks. Taking into account this model, this paper assesses the social strategies involved in the generation of heterogeneous social organization and its main components.
En este trabajo se propone que la complejidad social en los grupos de cazadores-recolectores surandinos es un producto del proceso de intensificación económica que se dio en la región a partir del Holoceno Medio. Este proceso involucró una estrategia de especialización económica en el uso de los camélidos silvestres, seguida por otra de diversificación relacionada con la domesticación de animales y plantas, y el establecimiento de un sistema de intercambio a larga distancia. A partir de esta propuesta se tratarán de evaluar las estrategias sociales involucradas en la generación de una organización social heterogénea y se discutirán sus componentes más relevantes.

South Africa's reintegration into the global economy post-1994 has not produced the expected levels of industrialisation and growth-enhancing structural transformation that has traditionally been achieved by developed countries in the past. South Africa faces the triple challenge of poverty, inequality and unemployment and needs structural growth that is inclusive and sustainable. However, trying to emulate the traditional structural transformative growth paths that developed countries have followed previously, will prove unsuccessful due to changes in the global economy. This paper, therefore, argues that an alternate growth path is needed, especially given that global warming and the effects of climate change act as a threat multiplier to economic growth and development. Furthermore, the world economy is shifting away from fossil fuels and resource depletion towards greener technologies and products. South Africa needs to adopt a growth path that accounts for the current climate and global context to ensure sustainable and inclusive growth for future competitiveness. This paper, using the Economic Complexity Methodology, identifies green industries that South Africa is best positioned to develop and grow given the existing knowledge and capabilities within the economy. A case study is conducted on the wind-power industry which proves to be a promising option given South Africa's current economic climate and the potential for employment creation. This paper aims to highlight the opportunities for the development of green industries in South Africa and the limitations that hinder this potential.

The affinity between the work of the Austrian economist Friedrich A. Hayek and the approach of Complexity Economics is widely recognized by the literature. In spite of this, there still is a lack of studies that seek to analyze in depth the relationship between Hayek and complexity. This dissertation is a contribution to the filling of this large gap in the literature. In the first part of the work, we analyze the various periods in the development of Hayek\'s vision of complexity, showing that this vision is strongly present in his works on knowledge, competition, methodology, evolution, and spontaneous order. In the second part, we explore how Hayek was influenced by two of the main precursors of modern complexity theory - cybernetics and general system theory - from the time he was working on his book on theoretical psychology, The Sensory Order (1952), until the end of his intellectual career.
A afinidade entre a obra do economista austríaco Friedrich A. Hayek e a abordagem da Economia e Complexidade é amplamente reconhecida pela literatura. Apesar disso, ainda há grande carência de estudos que busquem analisar de forma aprofundada a relação entre Hayek e a complexidade. Esta dissertação é uma contribuição para o preenchimento dessa grande lacuna na literatura. Na primeira parte do trabalho, os diversos períodos no desenvolvimento da visão de complexidade de Hayek são analisados, evidenciando-se como tal visão está fortemente presente em seus trabalhos sobre conhecimento, competição, metodologia, evolução e ordem espontânea. Na segunda parte, exploramos como Hayek foi influenciado por dois dos principais precursores da moderna teoria da complexidade - a cibernética e a teoria geral do sistema - desde o período em que estava trabalhando no seu livro sobre psicologia teórica, The Sensory Order (1952), até o final de sua carreira intelectual.

Les réseaux de télécommunication actuels offrent une interconnexion généralisée de terminaux dont les capacités de calculs et de mémoire évoluent sans cesse. De nouveaux comportements émergent face à une information devenue pervasive. L'utilisateur n'est plus passif, ni unique, c'est un acteur local du traitement de l'information. Une interface doit prendre en considération la variété des modes d'accès et d'usages qui conditionnent la présentation de tout contenu. La présentation de l'information se situe au carrefour de trois grands domaines indissociables : l'acquisition et le traitement du signal, l'ingénierie des données et des connaissances, l'interaction homme machine. Ce thème pluridisciplinaire, très proche du document numérique nous permet de comprendre et prévoir nos manières d'appréhender l'information numérique. Nous y retrouvons des sujets tels que la qualité de la numérisation et son évaluation. Cette thèse présente un socle théorique identifiant les problèmes posés par la communication numérique dans le contexte évoqué. Les éléments de solutions sont présentés par des réalisations techniques innovantes sur la reconnaissance de mots et la distance entre informations. Ces applications, issues des théories de la complexité et de la cybernétique, ont pour caractéristiques remarquables leur simplicité algorithmique face à la complexité des problèmes traités, et leur facilité d'appropriation par un utilisateur totalement inclus dans la boucle de traitement
Telecommunication network allow wider and wider range of interconnection of high capacities in computing, memory and bandwidth of terminals. New behaviour are emerging regarding becoming pervasive information. User is no more passive or singular, but a local actor in information processing. New accessibility modes and new use cases are fundamental trends in man machine interface studies. Information presentation is a kind of crossroad between three classical domains : signal acquisition and processing, data and knowledge engineering, man machine interaction. That means that the information presentation is a pluridisciplinar theme, very close from digital document with near subjects. This thesis presents a theorical base with the aim to identify problems of digital communication in the context of pervasive information. Results are presented through proof of concepts prototypes in character and word recognition, and information distance computing. These software are issued from complexity theory and cybernetic. Their main characteristics are represented by a very simple algorithmic solution, regarding complexity to process. An other interesting characteristics is a very handing by user totally included in process loop

This thesis explores the notion of complexity as related to accounting by relying upon aesthetic modes of inquiry. Prior studies have presented a variety of approaches to complexity in accounting, rendering the literature rich but puzzled. A number of scholars have explored the role of accounting in managing the complexity arising from the multiple overlapping and conflicting logics that come across the organization. Further studies have explored complexity as a feature of accounting and reporting design, which can obfuscate performance or reveal corporate aspirations. We argue that aesthetic approaches to ‘accounting for complexity’ and ‘complexity in accounting’ can reconcile the diverse findings, while providing innovative venues for research. The first chapter of this thesis aims to provide a critical review of prior studies on complexity in accounting and to systematize the diverse findings that these studies have offered, while outlining patterns for further accounting research on complexity. In the second chapter, we explore aesthetic complexity in the design of corporate reports by adopting a Baroque interpretive lens. The Baroque is known as the art of complexity, bold ornamentation, juxtaposition, as well as the grotesque, extravagance, flamboyance, and illusion. We draw on the experience of Plectra, a large European bank operating in more than 15 countries, to analyze the aesthetic features of its Integrated Report. We rely upon an ‘aesthetic inquiry’ into accounting to explore the emotional responses of the designers of the Integrated Report (i.e. the sustainability managers within Plectra), as they engage with the aesthetic features of the report in the attempt to represent ‘sustainable value’. This chapter demonstrates that aesthetic complexity in reporting design engages with the subjective/emotional sphere of its designers inside the organization, as they attempt to fill the conceptual ‘voids’ left in the meaning of ‘sustainable value’ and celebrate it. This attempt leads to an ongoing search for innovation in reporting design, while perpetuating the illusion of avoiding the void. We show that complexity in reporting design may provide its designers with a means for celebration, heroism, illusion, and consolation, while reassuring them from the horror vacui, i.e. the fear for ‘sustainable value’ to remain empty, and for sustainability managers to ‘disappear’. The third chapter explores the role of accounting in the management of complexity, as complexity is socially and spatially produced, and as it is augmented by aesthetic and transcendent aspects. By drawing upon archival sources concerning the project of construction of the baroque altar of St. Ignatius (1695 - 1699) in the Church of Gesù in Rome, Italy, we demonstrate how accounting provided a means for avoiding the lived space to jeopardize the conceived space of the project thereby enabling transcendent and aesthetic aspects to engage with other logics in the making of the altar. Such engagement ‘took on body’ in the altar, allowing a complex bundle of power and ideology to ‘materialize’.

La région MENA est aujourd’hui, au centre d’ambitieux enjeux économiques essentiellement en matière d’intégration régionale et de transformation structurelle. Toutefois, les Etats Arabes de cette région ont présenté des défaillances et une vulnérabilité importante dans le système économique et productif au lendemain des mouvements et des bouleversements politiques, économiques, sociales et populaires de très grande ampleur. Ces chocs apportent un lot de nouveaux défis à relever. L’objectif principal de cette thèse est d’étudier les nouvelles dynamiques du processus de transformation structurelle afin de proposer de nouvelles trajectoires de développement pour ces pays. Dans cette optique, nous abordons les questions liées aux déterminants et aux effets spatiaux de ce processus, à la relation entre d’une part la complexité économique et la pollution de l’air, et d’autre part, la complexité économique et les inégalités de genre en éducation. Pour cela, nous considérons un panel dynamique de 133 pays qui couvre une période longue et récente (1984 à 2014). En utilisant des données récentes et en intégrant des paramètres jusque-là peu utilisés, nous mettons en évidence des caractéristiques particulières du processus de complexification des systèmes productifs. D’un point de vue général, les résultats révèlent que les performances en matière de complexification des systèmes productifs sont très hétérogènes au sein des pays MENA et que leurs déterminants dépendent des caractéristiques des économies. Les fortes disparités observées s’expliquent, au-delà de l’effet significatif du revenu par habitant, par une carence dans le système institutionnel, éducatif en particulier dans l’accès à l’innovation, mais aussi à l’abondance des ressources naturelles ou encore à l’attractivité des investissements directs étrangers. Au-delà des caractéristiques individuelles des économies, l’analyse spatiale montre que des facteurs géographiques tels que le taux d’urbanisation, les accords commerciaux, et la localisation spatiale jouent un rôle très important dans le processus de transformation structurelle. Nous apportons également, grâce aux outils tirés de la mécanique classique, des réponses aux limites des modèles économiques traditionnels qui peinent à démontrer l’existence d’un processus d’accélération du développement économique
MENA countries is today, at the center of ambitious economic stakes mainly in regional integration and structural transformation. However, the Arab States of this region have suffered great shortcomings and vulnerability in the economic and productive system in the aftermath of massive political, economic, social and popular upheavals and upheavals. These shocks present a number of new challenges. The main objective of this thesis is to study the new dynamics of the structural transformation process in order to propose new development trajectories for these countries. In this context, we address issues related to the spatial determinants and effects of this process, the relationship between economic complexity and air pollution on the one hand, and economic complexity and inequalities on the other education. For this, we consider a dynamic panel of 133 countries covering an important and recent period (1984 to 2014). Using recent data and integrating previously little used parameters, we highlight particular characteristics of the process of complexification of productive systems. From a general point of view, the results reveal that the productivity performance of productive systems is very heterogeneous within MENA countries and that their determinants depend on the characteristics of the economies. The large disparities observed are explained, beyond the significant effect of per capita income, by a deficiency in the institutional system, particularly in terms of access to innovation, but also to the abundance of natural resources or the attractiveness of foreign direct investment. Beyond the individual characteristics of economies, spatial analysis shows that geographical factors such as urbanization rate, trade agreements, but especially spatial location play a very important role in the process of structural transformation.We also bring, thanks to the tools derived from classical mechanics, answers to the limits of traditional economic models which are difficult to demonstrate the existence of a process of accelerating economic development