Geography and Property Taxation

Property taxation is a state instrument which has had an enormous impact on many areas, particularly the regions of North America. This research note outlines areas of concern appropriate to a geography of property taxation and reviews the work of geographers and other social scientists which has considered the economic effects, social incidence and administrative efficacy of this form of taxation. It notes that this literature lacks historical perspective and argues that it would benefit from the adoption of historical materialist analysis. Such analysis would allow insight into historical change and would facilitate understanding of the class forces involved in that change. In so doing, it would help the geographer achieve a fuller understanding of the operation of property taxation in particular regions.Comme instrument d'administration publique, l'impôt foncier a profondément marqué de nombreuses régions, particulièrement en Amérique du Nord. La présente étude délimite les champs d'intérêt pertinents à une étude géographique de l'impôt foncier. On y trouvera en outre un survol des études que des géographes et d'autres spécialistes des sciences sociales ont consacrées aux effets économiques, à l'incidence sociale et à l'efficacité administrative de cette forme d'impôt. Or, ces études n'ont pas de perspective historique. À ce titre, la bibliographie consacrée à cette question gagnerait à inclure des analyses fondées sur une perspective historique et matérialiste. De telles analyses jetteraient un éclairage nouveau sur l'évolution historique du système fiscal et permettraient de mieux comprendre les forces de classe agissant sur cette évolution. L'étude géographique de l'application de l'impôt foncier dans telle ou telle région pourrait ainsi s'inscrire dans un cadre plus global

Neural Network Dynamics for Model-Based Deep Reinforcement Learning with Model-Free Fine-Tuning

Model-free deep reinforcement learning algorithms have been shown to be capable of learning a wide range of robotic skills, but typically require a very large number of samples to achieve good performance. Model-based algorithms, in principle, can provide for much more efficient learning, but have proven difficult to extend to expressive, high-capacity models such as deep neural networks. In this work, we demonstrate that medium-sized neural network models can in fact be combined with model predictive control (MPC) to achieve excellent sample complexity in a model-based reinforcement learning algorithm, producing stable and plausible gaits to accomplish various complex locomotion tasks. We also propose using deep neural network dynamics models to initialize a model-free learner, in order to combine the sample efficiency of model-based approaches with the high task-specific performance of model-free methods. We empirically demonstrate on MuJoCo locomotion tasks that our pure model-based approach trained on just random action data can follow arbitrary trajectories with excellent sample efficiency, and that our hybrid algorithm can accelerate model-free learning on high-speed benchmark tasks, achieving sample efficiency gains of 3-5x on swimmer, cheetah, hopper, and ant agents. Videos can be found at https://sites.google.com/view/mbm

Tax Exemptions in Montreal and Toronto, 1870 to 1920

Fondé sur une perspective matérialiste historique qui vient modérer l'évaluation de l'impact des institutions religieuses sur la formation des classes, cet article analyse, graphiques à l'appui, les débats sur les exonérations fiscales qui eurent cours à Montréal et à Toronto de 1870 à 1920. Les impôts locaux représentent une partie importante des revenus de ces deux grandes villes durant cette période-clé de l'urbanisation du Canada. Ainsi, les débats sur les exonérations fiscales allaient-ils permettre aux autorités locales de découvrir quels modes de perception et de gestion des ressources adopter. Le présent texte veut donc montrer, à partir du contenu de ces débats, les interactions qui existaient entre les classes sociales et les institutions religieuses, et qui constituaient un trait important des géographies politique et culturelle de Montréal et de Toronto.Informed by an historical materialist perspective tempered by an appreciation of the impact of religious institutions on class formations, this paper charts and explains debates over tax exemptions in Montréal and Toronto, from 1870 to 1920. Local taxation was an important part of the revenue source for these two great cities, in this important period in Canadian urbanization. Debates over exemption from taxation constitute an appraisal of the way the local state was to marshall resources. This paper explains these struggles through an understanding of the interplay of class and religion within the political and cultural geographies of Montréal and Toronto

Linear and nonlinear susceptibilities of a decoherent two-level system

The linear and nonlinear dynamical susceptibilities of a two level system are calculated as it undergoes a transition to a decoherent state. Analogously to the Glover-Tinkham-Ferrell sum rule of superconductivity, spectral weight in the linear susceptibility is continuously transferred from a finite frequency resonance to nearly zero frequency, corresponding to a broken symmetry in the thermodynamic limit. For this reason, the behavior of the present model (the Mermin model) differs significantly from the spin-boson model. The third order nonlinear susceptibility, corresponding to two-photon absorption, has an unexpected non-monotonic behavior as a function of the environmental coupling, reaching a maximum within the decoherent phase of the model. Both linear and nonlinear susceptibilities may be expressed in a universal form.Comment: 10 pages, 9 figure