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Sacrifie-t-on au nom de la croissance la lutte contre la pauvreté ? Discussion sur la croissance pro-pauvres au Sénégal
No full textLes autorités sénégalaises ont adopté un programme de lutte contre la pauvreté avec le soutien des institutions de Bretton Woods depuis 2002. Afin de tenter d’atteindre lesobjectifs de réduction de la pauvreté qui ont été fixés par les Objectifs du Millénaire pour le Développement (OMD), elles ont lancé en 2004 un programme de relance de lacroissance. Cet article discute de cette nouvelle stratégie de croissance et analyse de quelle manière elle est en mesure ou non de répondre aux objectifs de réduction de la pauvreté. On montre que les secteurs ciblés par le programme de croissance accéléréeainsi que les politiques choisies de soutien aux firmes multinationales ne sontprobablement pas assez favorables à l’emploi ni à la réduction de la pauvreté dans un horizon de moyen terme. Le programme est une vision d’une croissance macroéconomiqueportée par des secteurs, potentiellement dynamiques mais peu générateursde revenus du travail. Cette croissance est cependant voulue suffisamment élevée pour réduire la pauvreté. Tandis que ses fondements ne sont pas orientés vers une croissance pro-pauvres, aucun outil de redistribution de cette croissance vers les plus démunis n’est proposé.nonouirecherchenationa
Nouvelles technologies et nouvelles formes d’organisation du travail. Quelles conséquences pour l’emploi des salariés âgés ?
No full textCet article s’intéresse aux relations entre nouvelles technologies, changements organisationnels et structure par âge de la main-d’œuvre. Sous l’hypothèse d’une fonction de coût translog, nous considérons que les seuls facteurs variables sont, dans un premier temps, les effectifs des différents groupes d’âge puis, dans un second temps, les effectifs des groupes d’âge par qualification. Ce modèle est estimé sur le volet « entreprises » de l’enquête c.o.i., apparié au fichier des déclarations annuelles de données sociales (dads) et au fichier des bénéfices réels normaux (brn) sur la période 1995-1998. Nous mettons en évidence une complémentarité entre introduction de nouvelles technologies et déformation de la structure de la main-d’œuvre au détriment des salariés les plus âgés.To investigate the relationships between new technologies, innovative workplace practices and the age structure of the workforce we start from a classical labour-demand framework, assuming that the cost function is a restricted translog. Since we are interested in age effects, the only variable inputs are different types of labour indexed first by age and second by age and occupational groups. The data we use come from several French datasets: the c.o.i. survey and the dads and brn files. We find evidence that the wage bill share of older workers decreases when new technologies are adopted.nonouirecherchenationa
Do Banks Satisfy the Modigliani-Miller Theorem?
No full textThe capital structure of banks has become the focus of an extended debate among policymakers, regulators and academics. The seminal Modigliani-Miller (1958) theorem is seen as supportive of regulators' drive to require higher equity capital to banks. This raises the question on to what extent does Modigliani-Miller theorem hold for banks. This article brings a new insight of the Modigliani-Miller theorem by considering the implicit government guarantee offered to banks. Our theorem shows that a bank does not satisfy the Modigliani-Miller theorem. The main result indicates that banks will favor leverage instead of equity.nonouirechercheInternationa
Discretization of functionals involving the Monge-Ampère operator
No full textGradient flows in the Wasserstein space have become a powerful tool in the analysis of diffusion equations, following the seminal work of Jordan, Kinderlehrer and Otto (JKO). The numerical applications of this formulation have been limited by the difficulty to compute the Wasserstein distance in dimension >= 2. One step of the JKO scheme is equivalent to a variational problem on the space of convex functions, which involves the Monge-Ampère operator. Convexity constraints are notably difficult to handle numerically, but in our setting the internal energy plays the role of a barrier for these constraints. This enables us to introduce a consistent discretization, which inherits convexity properties of the continuous variational problem. We show the effectiveness of our approach on nonlinear diffusion and crowd-motion models.nonnonouirechercheInternationa
Improved Lieb-Oxford exchange-correlation inequality with gradient correction
No full textWe prove a Lieb-Oxford-type inequality on the indirect part of the Coulomb energy of a general many-particle quantum state, with a lower constant than the original statement but involving an additional gradient correction. The result is similar to a recent inequality of Benguria et al. [Int. J. Quantum Chem. 112, 1579 (2012)], except that the correction term is purely local, which is more usual in density functional theory. In an appendix, we discuss the connection between the indirect energy and the classical Jellium energy for constant densities. We show that they differ by an explicit shift due to the long range of the Coulomb potential.nonnonouirechercheInternationa
The Comparative Effects of Independence on Trade
No full textEmpirical evidence suggests that belonging to an empire favours trade by lowering transaction costs and establishing preferential trade agreements. Does the end of an empire invert this effect, and if so, through which channels? This paper uses an original dataset to explore the impact of independence on former colonies’ bilateral trade over the 1948-2007 period. We show large differences across empires. Whereas independence reduces the trade (imports and exports) between former French colonies and their coloniser, as well as with other colonies of the same empire, we do not find any comparable effect for former British colonies. We attribute this finding to the particularly protectionist trade policy implemented by France during the colonial era, and we are able to rule out alternative explanations related to transaction costs. We also find that after independence, all former colonies trade more with third countries, and we relate this result to the geographical diversification of trade.nonouirechercheinternationa
Pharmacoeconomic Considerations in Assessing and Selecting Congestive Heart Failure Therapies
No full textOver the last two decades the incidence of congestive heart failure (CHF) has increased with aging of the population and in spite of the decline in age-adjusted mortality rates due to coronary heart disease. Its management has seen substantial progress, embodied in the introduction of ACE inhibitors, initially as part of triple therapy in which they complemented diuretics and digoxin, and latterly as first-line therapy. The current consensus on treatment of CHF has been based on the multiple clinical studies performed with ACE inhibitors in which these agents have been shown to prevent a new cardiovascular accident and/or progression to more severe CHF in an increasingly wide range of patients with symptomatic CHF or post-infarction left ventricular dysfunction (ejection fraction ≤ 40% in some trials or ≤ 35% in others). Not only have the results shown a marked decrease in all-cause (and especially cardiovascular) mortality, but also a great number of cost-effectiveness analyses have shown the advantages of ACE inhibitors in terms of resource allocation: they are either cost saving or convincingly cost effective compared with standard treatment with digoxin and diuretics. Other drugs require similar cost and clinical analyses before they can earn their place in an add-on strategy. To date, cost savings have been documented only for β-blockers; implantable devices are still undergoing assessment. Two trends are now competing: one is to downplay add-on strategies and to recommend first-line therapy with ACE inhibitors and β-blockers at effective doses, supplemented by a raft of non-pharmaceutical measures (specialist nurses, patient education, dietary advice, exercise) in a multidisciplinary approach to CHF; the second is, on the contrary, to prescribe up to five drugs for patients with advanced CHF. The evidence that this decreases hospital admission rates and patient cost is more than anecdotal, but conclusive proof of cost effectiveness is still lacking and the approach presupposes dedicated structures. This review argues that despite technical limitations, a combined approach of CHF therapy based on clinical trials and cost-effectiveness analyses is essential. However, improvements can be made. The absence of sufficient comparative data still makes it difficult to choose between drugs within the same class; institutional purchasers need to conduct such analyses to identify the drugs best suited to their patients' profiles and budgetary constraints.nonouirechercheInternationa
Complex Gaussian multiplicative chaos
No full textIn this article, we study complex Gaussian multiplicative chaos. More precisely, we study the renormalization theory and the limit of the exponential of a complex log-correlated Gaussian field in all dimensions (including Gaussian Free Fields in dimension 2). Our main working assumption is that the real part and the imaginary part are independent. We also discuss applications in string theory; in particular we give a rigorous mathematical definition of the so-called Tachyon fields, the conformally invariant operators in critical Liouville Quantum Gravity with a central charge, and derive the original KPZ formula for these fields.nonnonouirechercheInternationa
Is work bad for health? The role of constraint vs choice
No full textDans cet article, nous passons en revue la littérature sur l'impact du travail sur la santé. Nous considérons le travail selon deux dimensions : (i)la marge intensive, à savoir le nombre d'heures travaillées par un individu et (ii) la marge extensive, c'est-à-dire le fait qu'un individu soit ou non en emploi, indépendamment du nombre d'heures travaillées. Nous montrons que l'effet néfaste du travail sur la santé, mis en évidence dans la littérature, est basé sur des situations dans lesquelles les salariés n'ont, pour l'essentiel, aucun contrôle (aucun choix) sur la quantité de travail qu'ils fournissent. Dans les faits, l'effet néfaste sur la santé ne proviendrait pas tant du travail en soi que de l'écart éventuel entre la quantité de travail effectivement fournie et la quantité désirée, tant à la marge intensive qu'à la marge extensive.This paper reviews the literature on the impact ofwork on health. We consider work along two dimensions: (i) the intensive margin, i.e. how many hours an individual works and (ii) the extensive margin, i.e. whether an individual is in employment or not, independent of the number of hours worked. We show that most of the evidence on the negative health impact of work found in the literature is based on situations in which workers have essentially no control (no choice) over theamount of work they provide. In essence, what is detrimental to health is not so much work per se as much as the gap which may exist between the actual and the desired amount of work, both at the intensive and extensive margins.nonnonouirechercheinternationa
Arbitrage and Duality in Nondominated Discrete-Time Models
No full textWe consider a nondominated model of a discrete-time financial market where stocks are traded dynamically and options are available for static hedging. In a general measure-theoretic setting, we show that absence of arbitrage in a quasi-sure sense is equivalent to the existence of a suitable family of martingale measures. In the arbitrage-free case, we show that optimal superhedging strategies exist for general contingent claims, and that the minimal superhedging price is given by the supremum over the martingale measures. Moreover, we obtain a nondominated version of the Optional Decomposition Theorem.nonnonouirechercheInternationa