Location, investment and regional policy: the contribution of the average effective tax rate theory

For decades, most industrialised countries have implemented some forms of fiscal and financial incentives to stimulate fixed capital formation. Tax cuts and capital grants are of great use in regional policy. Since these instruments mobilise huge amounts of public resources the issue of their efficiency is of particular interest for policymakers. The impact of taxation on investment income was traditionally apprehended through models measuring the effective tax rate on marginal investments. However recent literature, especially Devereux and Griffith (2002), showed the interest of resorting to an alternative tax measure – the effective average tax rate (EATR) - when firms face discrete investment choices that are expected to generate positive economic rent before tax. This effective average tax rate is defined by the difference between the net present value of the rent of the investment before and after taxes scaled by the net present value of the pre-tax income stream. In this sense, the effective average tax rate developed by Devereux and Griffith (2002) seems to be particularly relevant to shed a new light on the relative effectiveness of tax cuts and capital subsidy grants. In this paper we intend to compare the costs for public authorities to lower the corporate tax rate or to grant a capital subsidy. These public costs are directly affected by the variation of the after-tax revenue earned by the shareholder. The extent to which each policy must be implemented depends on the channel chosen by the government to stimulate investment. We pay attention to two of these channels: a reduction of the capital cost and a lowering of the EATR. Finally, in order to illustrate the relevance of our approach, we developed a numerical example for the Belgian case. JEL Classification: H25, H32 and R58

The Public-Private Sector Risk-Sharing in the French Insurance "Cat. Nat. System"

Twenty years ago, the French created a so far unique insurance scheme to cover damages due to natural catastrophes. This so-called ''Cat-Nat system'' combines private insurance industry, a state-guaranteed public reinsurance and the Treasury. We provide a simple game-theoretic model which seems to capture the situation of the concrete scheme. We find that, depending on its expectations, the government modulates its policy to induce private insurers adopting one of those two opposite strategies: (i) transfer all the covered risks to the public reinsurer and therefore simply behave as indemnification intermediaries; (ii) conserve the largest share of high risks. Il y a 20 ans, la France créait un système d assurance des sinistres dus aux catastrophes naturelles qui demeure unique au monde. Le système Cat.Nat est constitué d un partenariat entre l industrie privée de l assurance, un réassureur public et le Ministère des Finances. Nous proposons ici un modèle simple de ce système qui semble refléter concrètement son fonctionnement. Nous montrons que le gouvernement, suivant ses attentes, choisit de moduler sa politique de prise en charge de tels risques afin de conduire les assureurs privés à adopter l une des deux stratégies diamétralement opposées: (i) transférer tous les risques au réassureur public et ainsi se comporter comme de simples intermédiaires financiers; (ii) décider de conserver le plus possible de hauts risques.catastrophe risk-sharing, French insurance system, public-private sector partnership, signaling equilibria, partage de risques catastrophiques, système français d'assurance, partenariat public/privé, équilibres de signal

A model-free control strategy for an experimental greenhouse with an application to fault accommodation

Writing down mathematical models of agricultural greenhouses and regulating them via advanced controllers are challenging tasks since strong perturbations, like meteorological variations, have to be taken into account. This is why we are developing here a new model-free control approach and the corresponding intelligent controllers, where the need of a good model disappears. This setting, which has been introduced quite recently and is easy to implement, is already successful in many engineering domains. Tests on a concrete greenhouse and comparisons with Boolean controllers are reported. They not only demonstrate an excellent climate control, where the reference may be modified in a straightforward way, but also an efficient fault accommodation with respect to the actuators

Catastrophe risk sharing and public-private partnerships : From natural disasters to terrorism

Plusieurs catastrophes récentes appellent à reconsidérer le rôle des secteurs public et privé dans l'élaboration et le suivi de mécanismes de couverture des risques catastrophiques. Le développement de partenariats public-privé apparaît aujourd'hui l'une des voies prometteuses pour résoudre la problématique du financement des conséquences de tels événements à grande échelle. Néanmoins, à ce jour, peu de travaux analysent le rôle respectif des secteurs public et privé quant au développement de tels schémas de couverture adaptés à ces risques particuliers ainsi que l'efficacité des partages de risques public-privé qui en découlent. Cet article propose des éléments de réponse à travers une approche de politiques économiques portant sur le partage de ces risques entre assureurs privés et un réassureur public disposant d'une garantie illimitée du Trésor. Ces deux acteurs participent à un partenariat national dédié spécifiquement à la couverture de risques extrêmes, dans lequel la couverture "catastrophes" est obligatoire et la politique de "surprime catastrophes", payée par les assurés, est décidée par la direction du Trésor. Utilisant un modèle de jeu, nous montrons que dans un pays où les assureurs ont d'abord refusé de couvrir ces risques extrêmes par eux-mêmes, le gouvernement peut modifier une sa politique de surprime pour les inciter à participer à ce partenariat. Suivant la politique de surprime retenue, deux types de comportements stratégiques seront adoptés par les assureurs : (1) se comporter en simples intermédiaires financiers entre les citoyens/entreprises assuré(e)s et le réassureur public. Dans ce cas, ce dernier supportera une part beaucoup plus importante des risques; (2) supporter une large part des risques pour bénéficier d'incitations financières qui découlent de la politique gouvernementale de surprime. Le système de couverture contre les catastrophes naturelles établi en France en 1982, et les systèmes élaborés dans plusieurs pays après les attentats du 11 septembre 2001 pour couvrir contre le terrorisme de masse, illustrent l'analyse théorique.Terrorisme;Partenariats public-privés;Partage de risques;Catastrophes naturelles

Transposition from a batch to a continuous process for microencapsulation by interfacial polycondensation

A novel continuous process is proposed and investigated to produce microcapsules by interfacial polycondensation. Polymeric microcapsules are obtained via a two-step process including an initial emulsification of two immiscible fluids in static mixers and a subsequent interfacial polycondensation reaction performed in two different continuous reactors, the Deanhex heat exchanger/reactor or a classical coiledtube. This study is carried out through a step by step approach. A model system involving polyurea as the polymeric membrane and cyclohexane as the encapsulated species is chosen. A semi-batch reaction kinetic study is first performed in order to obtain kinetics data of the polycondensation reaction and to highlight hydrodynamic issues that can happen when running the encapsulation reaction in classical stirred tank. Parameters influencing droplets size obtained when carrying out emulsification in static mixers are then investigated. The hydrodynamic of the Deanhex reactor used is also characterized in terms of mixing time and residence time distribution. To validate the innovative continuous process, the emulsion droplets obtained at the static mixer outlet are encapsulated firstly in the Deanhex reactor and secondly in the coiled-tube. The apparent reaction kinetics and microcapsules characteristics corresponding to different operating conditions are discussed

Random Forests for Big Data

Big Data is one of the major challenges of statistical science and has numerous consequences from algorithmic and theoretical viewpoints. Big Data always involve massive data but they also often include online data and data heterogeneity. Recently some statistical methods have been adapted to process Big Data, like linear regression models, clustering methods and bootstrapping schemes. Based on decision trees combined with aggregation and bootstrap ideas, random forests were introduced by Breiman in 2001. They are a powerful nonparametric statistical method allowing to consider in a single and versatile framework regression problems, as well as two-class and multi-class classification problems. Focusing on classification problems, this paper proposes a selective review of available proposals that deal with scaling random forests to Big Data problems. These proposals rely on parallel environments or on online adaptations of random forests. We also describe how related quantities -- such as out-of-bag error and variable importance -- are addressed in these methods. Then, we formulate various remarks for random forests in the Big Data context. Finally, we experiment five variants on two massive datasets (15 and 120 millions of observations), a simulated one as well as real world data. One variant relies on subsampling while three others are related to parallel implementations of random forests and involve either various adaptations of bootstrap to Big Data or to "divide-and-conquer" approaches. The fifth variant relates on online learning of random forests. These numerical experiments lead to highlight the relative performance of the different variants, as well as some of their limitations

Growing Income Inequalities in Advanced

In this paper, we survey the literature that studies the issue of growing inequalities in advanced countries (the North). We firstly unveil the main facts concerning widening inequality in the North and we underlie the differences between countries and groups of countries. We put forward the concomitance of the rise in inequality with three key developments that are the three major explanations given to growing inequality : globalization, skill biased technological progress and institutional changes. We finally expose the mechanisms behind each explanation and examine the results of the empirical works that attempt to appraise their respective impacts. The overall diagnosis is that the three explanations are valid but (i) their weight may substantially differ across countries and sectors, and (ii) they interact in the determination of inequality

Mobiles as Portals for Interacting with Virtual Data Visualizations

We propose a set of techniques leveraging mobile devices as lenses to explore, interact and annotate n-dimensional data visualizations. The democratization of mobile devices, with their arrays of integrated sensors, opens up opportunities to create experiences for anyone to explore and interact with large information spaces anywhere. In this paper, we propose to revisit ideas behind the Chameleon prototype of Fitzmaurice et al. initially envisioned in the 90s for navigation, before spatially-aware devices became mainstream. We also take advantage of other input modalities such as pen and touch to not only navigate the space using the mobile as a lens, but interact and annotate it by adding toolglasses