Tax interaction dynamics among Belgian municipalities, 1984-1997

The purpose of this paper is to test econometrically the existence of fiscal interactions between Belgian municipalities. At the time of writing, the motivation was to provide scientific support to the lively debate on fiscal competition that took place among Belgian politicians in the late nineties. Two types of taxes are considered, for which Belgian municipalities have the decision power as to rates : the “centimes additionnels” on the personal income tax and the “précompte immobilier” which is a property tax. A dynamic adjustment model is specified and estimated using panel data for 598 municipalities over 15 years. The empirical results obtained bear upon two main points : (i) Some interaction definitely has prevailed between the municipalities’ fiscal choices made during the observation period, for both taxes; (ii) However, the adjustment reactions to the other municipalities’ fiscal choices have occured over time at the very low yearly pace of 6% and 10% respectively, of the discrepancy between the actual rates and the preferred rates.

Malaria, Production and Income of the Producers of Coffee and Cocoa: an Analysis from Survey Data in Côte d’Ivoire. Malaria, coffee and cocoa production and income

The sectors of coffee and cocoa represented in Côte d'Ivoire, before the political crisis, approximately 15% of the GDP and 40% of exports. The zones of production of these two cultures are in the forest area which is infected with malaria. The culture of these products is less constraining than that of the food crops such as rice or yam (one does not need to replant each year for example). However, the maintenance of the ground and of the trees and pest management contribute to obtain high yields. In addition, these products allow the producers to obtain monetary income. However, output is not the sole determinant of the level of income: precocity and speed of gathering, by permitting early sale, contribute to get higher income. In addition, food crops such as rice growing, are produced in the area. The objective of this paper is twofold, first, to evaluate the role of malaria on coffee and cocoa productions, second, to assess if the behaviour of rural households facing a liberalisation of the coffee and cocoa chains has an impact on their income. Three functions are thus estimated: production of coffee, production of cocoa and income. Data are taken from a survey carried out on 800 households (21 villages) in 1999 in the forest area of Danané. The main results are the absence of malaria impact on productions and the dominance of individual over collective sale strategies.cocoa, coffee, lowland rice, malaria, sharecropping, Côte d’Ivoire

Le phénomène des gros et petits mangeurs : existe-t-il vraiment des individus dotés d'un métabolisme énergétique plus efficace ?

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Malaria, Production and Income of the Producers of Coffee and Cocoa: an Analysis from Survey Data in Côte d'Ivoire. Malaria, coffee and cocoa production and income

The sectors of coffee and cocoa represented in Côte d'Ivoire, before the political crisis, approximately 15% of the GDP and 40% of exports. The zones of production of these two cultures are in the forest area which is infected with malaria. The culture of these products is less constraining than that of the food crops such as rice or yam (one does not need to replant each year for example). However, the maintenance of the ground and of the trees and pest management contribute to obtain high yields. In addition, these products allow the producers to obtain monetary income. However, output is not the sole determinant of the level of income: precocity and speed of gathering, by permitting early sale, contribute to get higher income. In addition, food crops such as rice growing, are produced in the area. The objective of this paper is twofold, first, to evaluate the role of malaria on coffee and cocoa productions, second, to assess if the behaviour of rural households facing a liberalisation of the coffee and cocoa chains has an impact on their income. Three functions are thus estimated: production of coffee, production of cocoa and income. Data are taken from a survey carried out on 800 households (21 villages) in 1999 in the forest area of Danané. The main results are the absence of malaria impact on productions and the dominance of individual over collective sale strategies

Parallel computation of entries of A-1

In this paper, we are concerned about computing in parallel several entries of the inverse of a large sparse matrix. We assume that the matrix has already been factorized by a direct method and that the factors are distributed. Entries are efficiently computed by exploiting sparsity of the right-hand sides and the solution vectors in the triangular solution phase. We demonstrate that in this setting, parallelism and computational efficiency are two contrasting objectives. We develop an efficient approach and show its efficacy by runs using the MUMPS code that implements a parallel multifrontal method

Implications of paleomagnetic results from the Permian Rodez basin for the late Variscan tectonics in the southern French massif Central.

A paleomagnetic study has been carried out on three sedimentary formations of the Permian Rodez basin in the southern France. Two of them yield paleomagnetic poles of Saxonian and Thuringian age showing counterclockwise rotation of moderate amplitude, during or after the Thuringian deposition. For the French Massif Central, contrary to its stable southern (Lodève basin) and eastern (Largentière basin) borders, on its southwestern border, in a large area including the Rodez, Saint-Affrique and perhaps Brive basins suffered rotations due to the extensional tectonics during the Late Variscan period

L'observation environnementale au prisme du paysage. Dynamiques paysagères, actions territoriales et représentations socio-spatiales contemporaines dans le territoire de l'OHM Pyrénées-Haut Vicdessos

International audienceSome people in charge of the OHM Pyrénées Haut Vicdessos underwent a methodological piece of research, whose aim was to turn the very landscape into a borderline tool between natural and social sciences. One singular point was to include the socio-spatial representations of the localpeople into the frame, through a close observation of both their sensibilities and expectations. Our results disclosed the complexity of the links between the very landscape, the way people look at it, and politics. Besides, such research entitled the present locals to reassess first the way their territory has been set in the long run and, next, the cultural bases of the place. In its turn, such reassessment enables the discussions and thinking that are prerequisite to the sustainable development of the territory.Dans le cadre de l'Observatoire Hommes-Milieux Pyrénées-Haut Vicdessos a été engagée une réflexion méthodologique visant à faire du paysage un outil pour une analyse interdisciplinaire à l'interface entre sciences naturelles et sciences sociales. L'objectif général du projet est de développer une observation qui s'intéresse aux évolutions paysagères en lien avec les différentes politiques à effet environnemental et territorial qui ont été, qui sont en train ou dont il est projeté qu'elles soient mises en œuvre dans le Vicdessos. La prise en compte des représentations socio-spatiales constitue une des originalités de ce projet. Il s'agit de construire une observation, qui ne soit pas seulement fondée sur la matérialité des environnements et des paysages, mais qui prenne également en compte les représentations sociales, les attentes et les sensibilités des acteurs et des populations. Les résultats obtenus restent partiels. Mais, ils montrent d'ores-et-déjà toute la complexité des relations s'établissant, dans la durée, entre les formes paysagères, les regards portés sur les paysages et les actions et les politiques menées dans les domaines du territoire, de l'environnement, du patrimoine ou du tourisme. La démarche utilisée permet en outre de placer les acteurs contemporains face à une histoire des modes d'actions sur l'espace et de leurs fondements culturels, afin de créer les conditions d'une concertation permettant l'émergence de valeurs partageables, fondements d'une réflexion sur le développement local et durable du territoire

Modeling 1D distributed-memory dense kernels for an asynchronous multifrontal sparse solver

To solve sparse systems of linear equations, multifrontal methods rely on dense partial LU decompositions of so-called frontal matrices; we consider a parallel asynchronous setting in which several frontal matrices can be factored simultaneously. In this context, to address performance and scalability issues of acyclic pipelined asynchronous factorization kernels, we study models to revisit properties of left and right-looking variants of partial $LU$ decompositions, study the use of several levels of blocking, before focusing on communication issues. The general purpose sparse solver MUMPS has been modified to implement the proposed algorithms and confirm the properties demonstrated by the models

Acoustical measurement of the shear modulus for thin porous layers

International audienceSimulations performed with the Biot theory show that for thin porous layers, a shear mode of the structure can be induced by a point-source in air located close to the layer. The simulations show that this mode is present around frequencies where the quarter wavelength of the shear Biot wave is equal to the thickness of the samples and show that it can be acoustically detected from the fast variations with frequency of the location of a pole of the reflection coefficient close to grazing incidence. The mode has been detected with this method for two reticulated plastic foams. For one of the foams studied, the velocity and the damping of the Rayleigh wave have been measured on a thicker layer of the same medium at higher frequencies, giving a real part of the shear modulus close to the one obtained from the measured location of the pole. The strong coupling of the shear mode with the acoustic field in air allows the measurement of the shear modulus without mechanical excitation