We describe an ensemble approach to learning salient spatial regions from arbitrarily partitioned simulation data. Ensemble approaches for anomaly detection are also explored. The partitioning comes from the distributed processing requirements of large-scale simulations. The volume of the data is such that classifiers can train only on data local to a given partition. Since the data partition reflects the needs of the simulation, the class statistics can vary from partition to partition. Some classes will likely be missing from some or even most partitions. We combine a fast ensemble learning algorithm with scaled probabilistic majority voting in order to learn an accurate classifier from such data. Since some simulations are difficult to model without a considerable number of false positive errors, and since we are essentially building a search engine for simulation data, we order predicted regions to increase the likelihood that most of the top-ranked predictions are correct (salient). Results from simulation runs of a canister being torn and from a casing being dropped show that regions of interest are successfully identified in spite of the class imbalance in the individual training sets. Lift curve analysis shows that the use of data driven ordering methods provides a statistically significant improvement over the use of the default, natural time step ordering. Significant time is saved for the end user by allowing an improved focus on areas of interest without the need to conventionally search all of the data. We have also found that using random forests weighted and distance-based outlier ensemble methods for supervised learning of anomaly detection provide significant accuracy improvements when compared to existing methods on the same dataset. Further, distance-based outlier and local outlier factor ensemble methods for unsupervised learning of anomaly detection also compare favorably to existing methods.

Cette dissertation est composée de trois articles traitant de sujets divers. Le premier développe une théorie sur la transmission de normes culturelles. Le second article traite de l'évolution des doctrines religieuses dans une économie productive. Enfin, le dernier article de cette dissertation est un travail joint avec Thierry Verdier. L'article propose une nouvelle approche des élections impliquant un nombre arbitraire de candidats. Cette problématique de recherche est importante non seulement quant à sa complexité théorique, mais aussi parce qu'elle permet d'étudier relativement simplement la structure des marchés politiques.Le premier article présente une théorie sur le développement de l'enfant et les pratiques parentales. Dans le modèle, un parent cherche à transmettre des normes comportementales à son enfant en lui envoyant des signaux, que l'enfant observe de manière imparfaite. L'enfant peut cependant augmenter la qualité des signaux qu'il reçoit en investissant dans l'acquisition de compétences cognitives.Nous établissons que les styles parentaux autoritaires ou permissifs décroissent l'accumulation de compétences cognitives. De plus, puisque les interactions entre parents et enfants visent à transmettre des normes comportementales, l'enfant développe un capital d'appréciation pour le développement de compétences cognitives.Notre perspective culturelle sur la question du développement cognitif fournit une grille d'interprétation utile pour divers résultats établis dans la littérature empirique sur le développement de l'enfant.Le second article propose une théorie de la prohibition religieuse contre l'usure et l'innovation et ses conséquences sur les activités et les occupations économiques.Comme une interdiction économique provenant de la religion majoritaire est soutenue par un risque d'exclusion sociale de ce groupe culturel, elle a moins d'effets sur les minorités religieuses. Cela implique que seules les minorités religieuses choisissent des activités qui vont à l'encontre de la prohibition à l'équilibre.Dans le dernier article, nous présentons une théorie micro-fondée de la concurrence politique à plusieurs candidats prenant une perspective ``d'organisation industrielle" de la politique. Nous présentons d'abord un modèle de vote aléatoire qui utilise des distributions introduites par le mathématicien français Maurice Fréchet et qui portent son nom. Ces distributions permettent d'exprimer les parts de vote des différents candidats comme des ``contest functions'', ce qui permet d'établir un théorème d'existence et d'unicité d'un équilibre des stratégies politiques dans des élections impliquant un nombre arbitraire de candidats.Le cadre analytique s'avère suffisamment souple pour traiter plusieurs applications sur des thèmes liés à la structure endogène des marchés politiques. Nous montrons en particulier que le degré d'information des électeurs sur les plateformes ainsi que les campagnes médiatiques impliquent un degré de fragmentation politique plus faible. / The first chapter of this dissertation presents a theory of child development and parental rearingpractices. In the model, a benevolent parent seeks to transmit cultural norms to her child, whoacquires cognitive skills and develops a capital of appreciation for adopting behaviors that accordwith these norms. Our cultural perspective on the issue of cognitive development provides aninterpretation grid for various results established in the empirical literature. It also permits to identifythe parental characteristics that are conducive to various parenting styles, to child neglect and tochild maltreatment.The second chapter provides a theory of religious prohibition against usury and innovation and itsconsequences on economic activities and occupations. As an economic prohibition from themajority religion is sustained by a threat of social exclusion from that cultural group, it has lesseffects on religious minorities. It then creates an occupational pattern where only the religiousminorities choose activities that transgress the prohibition. By creating resentment against thereligious minorities, this occupational pattern strengthens the diffusion of the majority religion in thepopulation. An economic prohibition is then instigated by the clerics in the majority religion,because it allows them to consolidate their norms and to increase the scope of their control overpopular masses. This work also demonstrates that an economic prohibition lasts longer whenreligious clerics can legitimize secular rulers and when the competition on the religious market isweaker.In the last chapter, we present a microfounded theory of multi-candidate political competition takingan "industrial organization" perspective of politics. The analytical framework is shown to be exibleenough to address several applications on the topics of special interest politics, coalition formationin the legislature in proportional elections, and redistribution under alternative electoral rules

The scope of this work is analysing how economic policies chosen by governments are influenced by the power of social groups. The core idea is taken from the single-mindedness theory, which states that preferences of groups and their ability to focus on the consumption of goods enable them to obtain the most favourable policies. This approach exploits the advantages of probabilistic voting theory, ability to manage the multidiemnsionality and possibility to study precisely how politicians tailor their policies to groups' features. Unlike classic probabilistic voting models, my theory assumes that the density function which captures the distribution of political preferences depends on consumption of goods and preferences of individuals. The higher the consumption of goods, the higher the density, the higher the political power. This mechanism is better explained by considering the role played by "swing voters". Since they are pivotal to changing the equilibrium, candidates must favour them because they realise that even a small change in policy could force them to vote for the other candidate, Thus, the lower the loyalty of voters for parties, the higher the benefit they obtain. As a consequence, these voters are better off and represent the winners of the political process.