Publications

Résumé In this study, we investigate monthly seasonality in the foreign exchange market. Given the well-known recurrent higher returns in some month than in others in stock markets around the world, we consider it likely that a seasonal outperformance of a country's stock market over another is associated with similar seasonal patterns in capital flows and exchange rates. A seasonal profit (carry trade) opportunity can be created by the simultaneous appreciation of a country's currency and the outperformance of its stock market. By focusing on the world's key currency pairs, the US dollar-Deutsche mark and the US dollar-euro, and by using a Markov-switching framework, we document persistent January and December effects in the foreign exchange market from 1971 to 2017. Analysis of the German-US stock returns differential and their bilateral capital flows reveal similar month effects in 65% of the whole sample.
Mots clés Carry trade, Markov-switching, UEP, Foreign currency market, Month effect, Seasonality
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Résumé Selon les projections récentes, les effectifs de médecins libéraux diminueront de 30 % d’ici à 2027 et la densité standardisée diminuerait jusqu’en 2023, créant des poches de sous-densité relativement nombreuses sur le territoire français métropolitain. L’article s’intéresse aux ajustements que les médecins généralistes de ville mettent en œuvre lorsque, sur leur territoire, ils sont d’ores et déjà confrontés à cette raréfaction. Les données utilisées sont celles du troisième panel des médecins généralistes enrichies d’indicateurs fournis par la CNAMTS. Nous nous sommes appuyés sur l’indicateur d’accessibilité potentielle localisé, développé par l’IRDES et la DREES, pour définir les zones les moins dotées en généralistes. En comparant les comportements des généralistes exerçant dans les zones les moins dotées à leurs homologues des zones mieux dotées, il est apparu d’abord que le planning d’activité du médecin tend à s’intensifier plutôt qu’à s’allonger. Nos données semblent en effet montrer que les rythmes de consultation dans les zones les moins dotées sont plus élevés, alors que le temps de travail global des généralistes s’avère quant à lui peu réactif à la densité en médecins alentour. On note aussi quelques différences statistiquement significatives sur les pratiques médicales : usage accru de certains médicaments, moins de renvoi vers des soins paramédicaux, suivis gynécologique probablement un peu moins réguliers, etc. Cependant, il semble que les différences ne sont pas statistiquement significatives pour les indicateurs de qualité des pratiques rattachés au dispositif de rémunération sur objectifs de santé publique (ROSP).
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Résumé We examine in this paper the complex decision-making processes that lead to investment location choice of Sovereign Wealth Funds (SWFs). Using a two-tiered dynamic Tobit panel model, we find that country-level factors do not have the same impact on the investment decision and the amount to invest and that SWFs tend to invest more frequently and with higher amounts in countries in which they already have invested. More specifically, we find that SWFs prefer to invest in countries with higher political stability, whereas they are more prone to investing for large amounts in countries that are less democratic and more financially opened. Our results also lend support to the idea that SWFs are prudent in the choice of target country concerning their investment decision but behave as more opportunistic investors concerning the amounts to be invested.
Mots clés Two-tiered dynamic Tobit panel model, Macroeconomic country factors, Targeted countries, Sovereign Wealth Funds
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Résumé This paper empirically examines the determinants of health care spending for 18 Arab world countries for the period 1995–2015 by using recently developed panel cointegration techniques. We conducted the same estimations for 3 sub-samples, namely high-income, upper-middle- and lower-middle-income countries to reduce the heterogeneity among them. Our empirical findings demonstrate that health care expenditure and its determinants are non-stationary, and revealed the existence of a long run relationship among variables. Furthermore, the estimation results suggest that income is not the only driver of health expenditure in the Arab world countries in the long run. Other variables such as medical progress and ageing population are also playing an important role in the increase of health care expenditure with major policy implications for the region in the long run. Furthermore, the results support that health care expenditure is a necessity good for the three income groups. Finally, the Pairwise Dumitrescu-Hurlin panel causality test shows evidence of a bidirectional causal relationship between health care expenditures and income for the full sample, as well as for the groups income.
Mots clés Panel causality, Panel cointegration, Arab world, Health Expenditure
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Résumé The main two methods of endogeneity correction for linear quantile regressions with their advantages and drawbacks are reviewed and compared. Then, we discuss opportunities of alleviating the constant effect restriction of the fitted-value approach by relaxing identification conditions.
Mots clés Two stage estimation, Quantile regression, Endogeneity, Fitted-Value Approach
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Résumé As illustrated by some French departments, how can we explain the existence of equilibria with different fertility and growth rates in economies with the same fundamentals , preferences, technologies and initial conditions? To answer this question we develop an endogenous growth model with altruism and love for children. We show that independently from the type of altruism, a multiplicity of equilibria might emerge if the degree of love for children is high enough. We refer to this condition as the love for children hypothesis. Then, the fertility rate is determined by expectations on the future growth rate and the dynamics are not path-dependent. Our model is able to reproduce different fertility behaviours in a context of completed demographic transition independently from fundamentals, preferences, technologies and initial conditions.
Mots clés Bal- anced Growth Path, Endogenous growth, Expectations, Love for Children, Fertility
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Résumé Une littérature récente en histoire économique4 s’attache à comprendre les avancées et les progrès de la société occidentale sur une longue période en analysant la façon dont la connaissance est créée et diffusée à travers les institutions qui en sont dépositaires. Derrière ces institutions, formelles, telles les universités et les sociétés savantes, ou informelles, telles la République des Lettres5, se trouvent des hommes qui, par leur activité intellectuelle, ont créé, compilé, discuté, transmis les progrès du savoir6. Cette littérature s’appuie sur la notion de capital humain, développée par Gary Becker7, qui comprend l’ensemble des connaissances et compétences détenues par un individu, et étudie son impact et à son évolution dans le temps. La transmission du savoir est au cœur des universités, dont le rôle dans la diffusion du progrès reste sujet à controverse. Alors que les universités médiévales constituent l’une des créations les plus innovantes de la société occidentale, et sont créditées de nombreuses influences positives8, elles sont souvent considérées comme endormies et sclérosées lors de la période moderne9. Leurs difficultés à s’ouvrir aux nouveaux domaines en expansion10, voire leur opposition à la modernité, sont souvent citées comme cause de leur déclin. Nous étudions dans ce travail le corps professoral de l’ancienne université d’Aix, créée en 1409, dans un terreau déjà fertile pour l’enseignement supérieur (école cathédrale, école de grammaire), et abolie en 1793 par la Convention. L’université d’Aix est, typiquement, vue habituellement11 comme une université aux débuts difficiles, avec un développement certain à la fin du XVIe siècle, mais caractérisée par un manque d’éclat général et un faible nombre d’étudiants. Les livres sur l’histoire d’Aix ou de la Provence lui accordent d’ailleurs peu de place12. Cette vision mitigée repose sur la taille de la population étudiante, sur une estimation, subjective, de l’originalité de la production scientifique, ou encore sur le manque de diversité de sa population étudiante13. Construire une base de données sur le corps professoral de l’université d’Aix permet de reconsidérer cette question sous un angle nouveau.
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Résumé Objectives: To evaluate the clinical and economic burden of head and neck squamous cell carcinoma (HNSCC) in France. Methods: All 53,255 incident adult patients discharged with a first diagnosis of HNSCC in 2010–2012 were identified from the 2008–2013 French National Hospital Discharge (PMSI) database. We conducted a retrospective longitudinal analysis of prognosis and direct costs attributable to HNSCC. Results: Direct medical costs attributable to HNSCC care amounted to 665 million euros in 2012 in France. The majority (62%) of incident patients were 64 years old or less at HNSCC diagnosis and incurred 1.3-fold higher mean direct costs as compared to elderly patients (41,909 vs 32,221 euros over 3 years, respectively; p
Mots clés Burden of disease, Costs, Prognosis, Head and neck squamous cell carcinoma, National Hospital discharge database
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Résumé In the aftermath of the U.S. financial crisis, both a sharp drop in employment and a surge in corporate cash have been observed. In this paper, based on U.S. data, we argue that the negative relationship between the corporate cash ratio and employment is systematic, both over time and across firms. We develop a dynamic general equilibrium model where heterogenous firms need cash and external liquid funds in their production process. We analyze the dynamic impact of aggregate shocks and the cross-firm impact of idiosyncratic shocks. We show that external liquidity shocks generate a negative comovement between the cash ratio and employment, as documented in the data.
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Résumé Background : Health state utility (HSU) is a core component of QALYs and cost-effectiveness analysis, although HSU is rarely estimated among a representative sample of patients. We explored the feasibility of assessing HSU in head and neck cancer from the French National Hospital Discharge database. Methods: An exhaustive sample of 53,258 incident adult patients with a first diagnosis of head and neck cancer was identified in 2010–2012. We used a cross-sectional approach to define five health states over two periods: three "cancer stages at initial treatment" (early, locally advanced or metastatic stage); a "relapse state" and otherwise a "relapse-free state" in the follow-up of patients initially treated at early or locally advanced stage. In patients admitted in post-acute care, a two-parameter graded response model (Item Response Theory) was estimated from all 144,012 records of six Activities of Daily Living (ADLs) and the latent health state scale underlying ADLs was calibrated with the French EQ-5D-3 L social value set. Following linear interpolation between all assessments of the patient, daily estimates of utility in post-acute care were averaged by health state, patient and month of follow-up. Finally, HSU was estimated by health state and month of follow-up for the whole patient population after controlling for survivorship and selection in post-acute care. Results: Head and neck cancer was generally associated with poor HSU estimates in a real-life setting. As compared to “distant metastasis at initial treatment”, mean HSU was higher in other health states, although numerical differences were small (0.45 versus around 0.54). It was primarily explained by the negative effects on HSU of an older age (38.4% aged ≥70 years in “early stage at initial treatment”) and comorbidities (> 50% in other health states). HSU estimates significantly improved over time in the “relapse-free state” (from 8 to 12 months of follow-up). Conclusions: HSU estimates in head and neck cancer were primarily driven by age at diagnosis, comorbidities, and time to assessment of cancer survivors. This feasibility study highlights the potential of estimating HSU within and across severe conditions in a systematic way at the national level.
Mots clés Head and neck cancer, Health state utility, EQ-5D-3L, QALYs, Cost-effectiveness analysis, Activities of daily living, Item response theory, National Hospital discharge database
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