IMF programs and tax effort What role for institutions in Africa?

When compared to other developing countries, most Sub-Saharan African countries are characterized by a disappointing level of development. Among the factors explaining this poor performance, the inadequate supply of public goods is often advocated. This inadequate supply is due either to poor efficiency of public expenditure, or to an insufficient tax effort. This paper is focused on this last factor. One of the reasons for the low level of public revenues could be the weak impact of the IMF programs on the tax effort. In the agreements that developing countries reach with the IMF, they commit to reduce their macro-economic imbalances, notably fiscal deficit, to a sustainable level. The measures necessary to achieve the overall budgetary objectives apply mainly to public expenditures as they are easy to reduce in the short term. However, the hypothesis of a positive effect of IMF programs must be considered: one objective of the African governments could be to maintain public expenditures at their previous level. To this end, African governments could choose to mobilize additional public revenues. Thus, most of IMF programs promote tax reforms leading to a more effective policy of public revenue mobilization. This last scenario of an increase of the level of public revenue is corroborated by the econometric analysis. The level of public revenue depends, among other factors, on the quality of institutions. However, the institutional quality of custom and tax administrations is weaker in Africa than elsewhere. This poor quality reduces the efficiency of IMF programs which may have a lower impact on the level of public revenue in African countries. These results point up two main lessons for the IMF (and more generally for lenders) and for recipient countries: 1) The role of technical assistance associated with the IMF programs is crucial, since it enables capacity reinforcement of the technical administrations in charge of the definition and implementation of the reform; 2) The technical assistance for tax and custom administrations must be strengthened for those countries which initially have a poor quality of bureaucracy.

IMF programs and tax effort What role for institutions in Africa?

When compared to other developing countries, most Sub-Saharan African countries are characterized by a disappointing level of development. Among the factors explaining this poor performance, the inadequate supply of public goods is often advocated. This inadequate supply is due either to poor efficiency of public expenditure, or to an insufficient tax effort. This paper is focused on this last factor. One of the reasons for the low level of public revenues could be the weak impact of the IMF programs on the tax effort. In the agreements that developing countries reach with the IMF, they commit to reduce their macro-economic imbalances, notably fiscal deficit, to a sustainable level. The measures necessary to achieve the overall budgetary objectives apply mainly to public expenditures as they are easy to reduce in the short term. However, the hypothesis of a positive effect of IMF programs must be considered: one objective of the African governments could be to maintain public expenditures at their previous level. To this end, African governments could choose to mobilize additional public revenues. Thus, most of IMF programs promote tax reforms leading to a more effective policy of public revenue mobilization. This last scenario of an increase of the level of public revenue is corroborated by the econometric analysis. The level of public revenue depends, among other factors, on the quality of institutions. However, the institutional quality of custom and tax administrations is weaker in Africa than elsewhere. This poor quality reduces the efficiency of IMF programs which may have a lower impact on the level of public revenue in African countries. These results point up two main lessons for the IMF (and more generally for lenders) and for recipient countries: 1) The role of technical assistance associated with the IMF programs is crucial, since it enables capacity reinforcement of the technical administrations in charge of the definition and implementation of the reform; 2) The technical assistance for tax and custom administrations must be strengthened for those countries which initially have a poor quality of bureaucracy.cerdi

IMF programs and tax effort What role for institutions in Africa?

When compared to other developing countries, most Sub-Saharan African countries are characterized by a disappointing level of development. Among the factors explaining this poor performance, the inadequate supply of public goods is often advocated. This inadequate supply is due either to poor efficiency of public expenditure, or to an insufficient tax effort. This paper is focused on this last factor. One of the reasons for the low level of public revenues could be the weak impact of the IMF programs on the tax effort. In the agreements that developing countries reach with the IMF, they commit to reduce their macro-economic imbalances, notably fiscal deficit, to a sustainable level. The measures necessary to achieve the overall budgetary objectives apply mainly to public expenditures as they are easy to reduce in the short term. However, the hypothesis of a positive effect of IMF programs must be considered: one objective of the African governments could be to maintain public expenditures at their previous level. To this end, African governments could choose to mobilize additional public revenues. Thus, most of IMF programs promote tax reforms leading to a more effective policy of public revenue mobilization. This last scenario of an increase of the level of public revenue is corroborated by the econometric analysis. The level of public revenue depends, among other factors, on the quality of institutions. However, the institutional quality of custom and tax administrations is weaker in Africa than elsewhere. This poor quality reduces the efficiency of IMF programs which may have a lower impact on the level of public revenue in African countries. These results point up two main lessons for the IMF (and more generally for lenders) and for recipient countries: 1) The role of technical assistance associated with the IMF programs is crucial, since it enables capacity reinforcement of the technical administrations in charge of the definition and implementation of the reform; 2) The technical assistance for tax and custom administrations must be strengthened for those countries which initially have a poor quality of bureaucracy

Financement externe et politique budgétaire : le rôle du Stabex

In the literature, when the price of primary products is booming, developing countries are generally facing an increase in the availability of foreign financing. The STABEX payments should occur after a shortfall export earnings, and as a consequence when government revenues are falling. We show that these payments, when they are made during periods of low real government revenues, allow for additional public expenditures. On the contrary, when payments are made during periods of high real revenues, they substitute for other ways of financing and have no expansionary effect. This is a strong argument in favour of STABEX.

Experimental quantification of the seismoelectric transfer function and its dependence on conductivity and saturation in loose sand

International audienceUnder certain circumstances, seismic propagation within porous media may be associated toa conversion of mechanical into electromagnetical energy known as a seismoelectromagneticphenomemon. The propagation of fast compressional P-waves is more specifically associatedto manifestations of a seismoelectric field linked to fluid flow within the pores. The analysisof seismoelectric phenomena, which requires combining the theory of electrokinetics to Biot’stheory of poroelasticity, provides us with a transfer function noted E/ü that links the coseismicseismoelectric field E to the seismic acceleration u. In order to measure the transfer function,we have developed an experimental set-up enabling seismoelectric laboratory observation inunconsolidated quartz sand within the kilohertz range. The investigation focused on the impactof fluid conductivity and water saturation over the coseismic seismoelectric field. Duringthe experiment, special attention was given to the accuracy of electric field measurements. Weconcluded that, in order to obtain a reliable estimate of the electric field amplitude, the dipolefrom which the potential differences are measured should be of much smaller length than thewavelength of the propagating seismic field. Time-lapse monitoring of the seismic velocitiesand seismoelectric transfer functions were performed during imbibition and drainage experiments.In all cases, the quantitative analysis of the seismoelectric transfer function E=u was ingood agreement with theoretical predictions. While investigating saturation variations from theresidual water saturation to full saturation, we showed that the E/ü ratio undergoes a switchin polarity at a particular saturation S, also implying a sign change of the filtration, traducinga reversal of the relative fluid displacement with respect to the frame. This sign change atcritical saturation S stresses a particular behaviour of the poroelastic medium: the droppingof the coseismic electric field to zero traduces the absence of relative pore/fluid displacementsrepresentative of a Biot dynamically compatible medium.We concluded from our experimentalstudy in loose sand that measurements of the coseismic seismoelectric coupling may provideinformation on fluid distribution within the pores, and that the reversal of the seismoelectricfield may be used as an indicator of the dynamically compatible state of the medium

Extreme congestion of microswimmers at a bottleneck constriction

When attracted by a stimulus (e. g. light), microswimmers can build up very densely at a constriction and thus cause clogging. The micro-alga \textit{Chlamydomonas Reinhardtii} is used here as a model system to study this phenomenon. Its negative phototaxis makes the algae swim away from a light source and go through a microfabricated bottleneck-shaped constriction. Successive clogging events interspersed with bursts of algae are observed. A power law decrease is found to describe well the distribution of time lapses of blockages. Moreover, the evacuation time is found to increase when increasing the swimming velocity. These results might be related to the phenomenology of crowd dynamics and in particular what has been called the Faster is Slower effect in the dedicated literature. It also raises the question of the presence of tangential solid friction between motile cells densely packed that may accompany arches formation. Using the framework of crowd dynamics we analyze the microswimmers behavior and in particular question the role of hydrodynamics

Analyse expérimentale et numérique de la dynamique d'arbres verts de petits diamètres soumis à l'impact d'un bloc rocheux

Afin d'évaluer le rôle de protection des forêts contre les chutes de blocs, un modèle éléments finis d'impact d'un bloc sur une tige de bois vert a été développé. Le modèle réalisé sous CAST3M intègre les non-linéarités géométriques et matérielles régissant l'impact. En particulier, un algorithme de gestion du contact tige/bloc issu des Méthodes aux Eléments Discrets a été développé. La calibration est faite à partir d'essais d'impact de type pendule de Mouton. Ce modèle met en évidence les échanges énergétiques et les modifications de cinématique du bloc lors de l'impact