Self-control and savings

We reconsider the well-established paradigm of a rational individual's choice of a consumption schedule, building on the idea that human beings devote resources to withstand their desire for immediate consumption, i.e. to become more patient, thereby making less remote the pleasure derived from deferred consumption. We construct an infinite-horizon model of a small open economy, in which individuals can accumulate a stock of personal capital that reduces the discount on future consumption. Personal capital captures the effect of a conumer's past experience and choices on his future utilities. Our main results are: i) when individuals are heterogenous with respect to ability to become patient all individuals exhibit the same rate of time preference in the long run; ii) effort is rewarded in the long run to the extent that individuals who need to make more effort to become patient are wealthier and enjoy a higher level of utility bin the steady state. The latter result stems from the complementarity between personal capital and deferred consumption. JEL Classification: E13

Intergenerational altruism and neoclassical growth models

This paper surveys intergenerational altruism in neoclassical growth models. It first examines Barro's approach to intergenerational altruism, whereby successive generations are linked by recursive altruistic preferences. Individuals have an altruistic concern only for their children, who in turn also have altruistic feelings for their own children. The conditions under which the Ricardian equivalence (debt neutrality) theorem applies are specified. The effectiveness of fiscal policy is further analysed in the context of an economy populated by heterogeneous families differing with respect to their degree of intergenerational altruism. Other forms of altruism, referred to as ad hoc altruism, are also examined, along with their implications for fiscal policy. JEL Classification: E13, D64, E62, C60altruism, fiscal policy, Neoclassical general aggregative models

Public pensions and growth

This paper investigates the relationship between the size of an unfunded public pension system and economic growth in an overlapping generation economy, in which altruistic parents finance the education of their children and leave bequests. Unlike the existing literature, we model intergenerational altruism by assuming that children's income during adulthood is an argument of parental utility. Unfunded public pensions can promote growth when families face liquidity constraints preventing them from investing optimally in the education of their children. We consider two alternative ways of financing a public pension system, either by levying social contributions in a lump-sum manner or in proportion to labour income. We find that there is no case for unfunded public pensions in economies where bequests are operative. By contrast, there exists a growth-maximising size of the public pension system in economies where bequests are not operative and individuals are sufficiently patient JEL Classification: H55, I20, D91Education, Growth, Public pension

Perspectives anthropologiques : images, tradition et cinéma en Afrique noire au sud du Sahara

Il existe dans les cultures africaines au sud du Sahara (mais aussi dans de nombreuses autres cultures de par le monde) une adhésion très forte aux images, même et surtout si elles transforment la ou les réalités auxquelles elles prétendent ressembler. Cet article part du principe que les images sont toujours codées culturellement, à la fois par ceux qui les font naître, par ceux qui les véhiculent et par ceux qui les reçoivent. Le cinéma africain, qui désormais inclut des réalisatrices, permet au public africain, inconsciemment ou pas, de négocier avec son environnement culturel, matériel et politique en perpétuelle mouvance.African cultures from the Sub-Sahara (as well as many other cultures worldwide) evince a very strong interest for images, all the more so if these transform the reality(-ies) to which they claim some resemblance. This article takes as its premise the fact that images are always culturally encoded, be it by those who create them, those who circulate them or those who receive them. African cinema, which now involves female directors, enables African audiences, unconsciously or not, to negotiate with their ever-changing cultural, material and political environment

Debt stabilizing fiscal rules

Unstable government debt dynamics can typically be corrected by various fiscal instruments, like appropriate adjustments in government spending, public transfers, or taxes. This paper investigates properties of state-contingent debt targeting rules which link stabilizing budgetary adjustments around a target level of long-run debt to the state of the economy. The paper establishes that the size of steady-state debt is a key determinant of whether it is possible to find a rule of this type which can be implemented under all available fiscal instruments. Specifically, considering linear feedback rules, the paper demonstrates that there may well exist a critical level of debt beyond which this is no longer possible. From an applied perspective, this finding is of particular relevance in the context of a monetary union with decentralized fiscal policies. Depending on the level of long-run debt, there might be a conflict between a common fiscal framework which tracks deficit developments as a function of the state of the economy and the unrestricted choice of fiscal policy instruments at the national level. JEL Classification: E63, H62fiscal regimes, overlapping generations

Debt stabilizing fiscal rules

Unstable government debt dynamics can typically be corrected by various fiscal instruments, like appropriate adjustments in government spending, public transfers, or taxes. This paper investigates properties of state-contingent debt targeting rules which link stabilizing budgetary adjustments around a target level of long-run debt to the state of the economy. The paper establishes that the size of steady-state debt is a key determinant of whether it is possible to find a rule of this type which can be implemented under all available fiscal instruments. Specifically, considering linear feedback rules, the paper demonstrates that there may well exist a critical level of debt beyond which this is no longer possible. From an applied perspective, this finding is of particular relevance in the context of a monetary union with decentralized fiscal policies. Depending on the level of long-run debt, there might be a conflict between a common fiscal framework which tracks deficit developments as a function of the state of the economy and the unrestricted choice of fiscal policy instruments at the national levelFiscal regimes, overlapping generations

Next Generation High Throughput Satellite System

This paper aims at presenting an overview of the state-of-the-art in High Throughput Satellite (HTS) systems for Fixed Satellite Services (FSS) and High Density-FSS. Promising techniques and innovative strategies that can enhance system performance are reviewed and analyzed aiming to show what to expect for next generation ultra-high capacity satellite systems. Potential air interface evolutions, efficient frequency plans,feeder link dimensioning strategies and interference cancellation techniques are presented to show how Terabit/s satellite myth may turn into reality real soon

Diversité des modèles d'évolution géodynamique au paléoproterozoïque . Comparaison entre le craton ouest africain et le craton de chine du nord.

International audienceL'évolution géodynamique au Paléoprotérozoïque reste un sujet débattu, les raisons principales étant le manque de datations, les différences d'interprétations structurale, et l'imprécision de la reconstruction paléogéographique du super continent paléoprotérozoïque vers 1.8 Ga. Schématiquement, deux modèles s'opposent

Diversité des modèles de genèse crustale au paléoprotérozoïque. Exemple de la comparaison entre le Craton Ouest Africain et le Craton de Chine du Nord.

L'évolution géodynamique au Paléoprotérozoïque reste un sujet débattu, les raisons principales étant le manque de datations, les différences d'interprétations structurale, et l'imprécision de la reconstruction paléogéographique du super continent paléoprotérozoïque vers 1.8 Ga. Schématiquement, deux modèles s'opposent. Nous comparons ici deux domaines paléo protérozoïques à comportements très différents situés en Afrique de l'Ouest WAC (2.3 Ga à 1.9 Ga) et en Chine du Nord entre 2.15 Ga à 1.85 G

Appuis et obstacles dans l'usage didactique des modélisations d'accompagnement pour une éducation au développement durable

International audienceCompanion modelling1 associates simulation using a Multi agent system, a Geographical Information System and role playing in order to create a model and to simulate dynamics of eco-socio-systems. Their main aims are to help taking decision about complex problems related to management of resources, natural patrimonies and biodiversity. We have enlightened different supports and obstacles for their didactic transposition in vocational teaching in agriculture. The companion modellings can allow to sensitize to eco-socio-system dynamics ; their internal transposition is necessary to make them considered by the learner as a mirror of the reality and to allow him to be involved and to change during the game.Les modélisations d'accompagnement, en tentant de prendre en compte la dynamique d'écosocio-systèmes, se veulent être un outil d'aide à la décision dans le cadre de problématiques complexes telles que la gestion de la biodiversité. Conçues par et avec les acteurs du territoire, elles associent un système multi-agent, un jeu de rôle et un système d'information géographique qui visualise l'évolution du territoire en fonction des choix pris par les acteurs durant le jeu. Nous avons mis en évidence différents appuis et obstacles à la transposition didactique dont elles font l'objet dans l'enseignement agricole. Si les modélisations peuvent permettre de répondre à des objectifs de sensibilisation relatifs au fonctionnement d'écosocio-systèmes complexes, une transposition interne se justifie pour leur permettre d'être conçues comme miroir d'une réalité, pouvant permettre l'implication et l'évolution de l'élève dans le jeu