Publications

Abstract Purpose To describe: (i) patterns of self-employment and social welfare provisions for self-employed and salaried workers in several European countries; (ii) work-related outcomes after cancer in self-employed people and to compare these with the work-related outcomes of salaried survivors within each sample; and (iii) work-related outcomes for self-employed cancer survivors across countries. Methods Data from 11 samples from seven European countries were included. All samples had cross-sectional survey data on work outcomes in self-employed and salaried cancer survivors who were working at time of diagnosis (n = 22–261 self-employed/101–1871 salaried). The samples included different cancers and assessed different outcomes at different times post-diagnosis. Results Fewer self-employed cancer survivors took time off work due to cancer compared to salaried survivors. More self-employed than salaried survivors worked post-diagnosis in almost all countries. Among those working at the time of survey, self-employed survivors had made a larger reduction in working hours compared to pre-diagnosis, but they still worked more hours per week post-diagnosis than salaried survivors. The self-employed had received less financial compensation when absent from work post-cancer, and more self-employed, than salaried, survivors reported a negative financial change due to the cancer. There were differences between self-employed and salaried survivors in physical job demands, work ability and quality-of-life but the direction and magnitude of the differences differed across countries. Conclusion Despite sample differences, self-employed survivors more often continued working during treatment and had, in general, worse financial outcomes than salaried cancer survivors. Other work-related outcomes differed in different directions across countries.
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Abstract In this paper, we study the impact of oil price returns on sovereign Credit Default Swaps (CDS) spreads for two major oil producers, Russia and Venezuela. Using daily spreads from 2008 to 2015 through a Time Varying Transition Probabilities Markov Switching model, our results show that crude oil price and its volatility are critical determinants of their sovereign debt. We highlight some differences between the two countries, depending on the state of the economy. Moreover, global and local factors play a major role in the determination of sovereign CDS spreads.
Keywords Russia, Venezuela, Time series modeling, Markov-switching, Sovereign Credit Default Swaps, Oil prices
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Abstract Introduction Les technologies de l’information et de la communication ont permis la naissance du web 2.0, caractérisé par la mise en place et l’utilisation de nouveaux outils collaboratifs de communication tels que les blogs, les wikis, les fils RSS et les réseaux sociaux. En s’appropriant ces outils, une médecine participative basée sur le partage d’informations et d’expériences entre professionnels, patients et tout acteur de la santé s’est développée. Depuis juin 2012, une communauté médicale échange sur Twitter avec le hashtag #DocTocToc et contribue à la naissance de la e-santé sur ce réseau social. L’objectif de cette étude est d’analyser les principales thématiques des demandes effectuées via le hashtag #DocTocToc par les médecins généralistes entre juin 2012 et mars 2017. Méthodes Une collecte de données par une méthode de « web scraping » a permis de constituer un corpus de tweets dont les auteurs ont été identifiés manuellement afin de procéder à un échantillonnage, de façon à ne conserver que les tweets émis par les médecins généralistes. Une étape de prétraitement a permis de transformer les formes potentiellement non reconnues par les logiciels de traitement du langage naturel. Le corpus a été appréhendé à l’aide de deux approches : une approche lexicale via le logiciel Iramuteq® et une indexation terminologique par l’extracteur de concepts multi-terminologiques (ECMT) du Catalogue et index des sites médicaux francophones (CISMeF). Résultats Sur les 12 716 tweets recueillis, 7366 étaient rédigés par des médecins généralistes et ont été analysés. L’approche lexicale détermine deux grands mondes lexicaux représentés sous forme de dendrogramme, l’un en lien avec les demandes médico administratives relatives à la gestion du cabinet et à la prise en charge sociale du patient, l’autre en lien avec les demandes d’ordre purement médicales. La méthode d’indexation terminologique met en évidence les spécialités médicales pourvoyeuses de demandes de télé-expertise : gynécologie, neurologie, infectiologie, pédiatrie, cardiologie, dermatologie ; et permet de les croiser avec l’objectif de la demande : diagnostic, thérapeutique. Conclusion Sur Twitter®, le hashtag #DocTocToc est utilisé par les médecins généralistes comme un espace de partage informel d’informations en matière de santé mais aussi de gestion de problèmes administratifs et sociaux. Le DocsTocToc se présente comme un groupe d’échange de pratique à grande échelle ou le médecin compte sur l’avis de ses pairs.(Fig. 1)
Keywords Text mining, Twitter, E-santé, Communication, Big data
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Abstract We develop a model of cross-border acquisitions in which the foreign acquirer's ownership choice reflects a trade-off between easing the target's credit constraints and the costs of operating in an environment with weak institutions. Data on domestic and foreign acquisitions in emerging markets over the period 1990–2007 support the model predictions. The share of full foreign acquisitions is higher in sectors more reliant on external finance, in countries with lower financial development, and in countries with higher institutional quality. Sectoral external finance dependence accentuates the effect of country-level financial development and institutional quality. By contrast, the level of foreign ownership in partial acquisitions is insensitive to institutional factors and depends weakly on financial factors.
Keywords Institutional quality, Financial development, Mergers and acquisitions, Foreign ownership, Foreign direct investment
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Abstract As it is documented, households’ investment in their own education (human capital) is negatively related to the number of children individuals will have and requires some loans to be financed. We show that this contributes to explain episodes of bubbles associated to higher growth rates. This conclusion is obtained in an overlapping generations model where agents choose to invest in their own education and decide their number of children. A bubble is a liquid asset that can be used to finance either education or the cost of rearing children. The time cost of rearing children plays a key role in the analysis. If the time cost per child is sufficiently high, households have only a small number of children. Then, the bubble has a crowding-in effect because it is used to provide loans to finance investments in education. On the contrary, if the time cost per child is low enough, households have a large number of children. Then, the bubble is mainly used to finance the total cost of rearing children and has a crowding-out effect on investment. Therefore, the new mechanism we highlight shows that a bubble enhances growth if the economy is characterized by a high rearing time cost per child.
Keywords Human capital, Fertility, Sustained growth, Bubble
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Abstract ICT components, such as microprocessors, may be embodied in other capital goods not recorded as ICT in National Accounts. We name ‘indirect ICT investment’ the value of embodied ICT components in non-ICT investment. The paper provides estimates of ‘indirect ICT investment’ based on detailed and unpublished Supply-Use tables (SUT) in 12 OECD countries: Australia, Belgium, Canada, Chile, Czech Republic, Denmark, France, Germany, Japan, Israel, Mexico, New Zealand, the United Kingdom, and the United States.Our main finding is that ICT investment appears significantly higher when considering its indirect component, the average increase being about 35%. The inclusion of indirect ICT investment, excluding software (for which firms’ expenditures are difficult to measure), changes significantly the relative position of countries with respect to the ICT intensity of their investments. The inclusion of software further increases indirect ICT investment but the increase is smaller (in percentage) than without this inclusion. A final result, but concerning only three countries, it that the diagnosis of a stabilisation, or even a decrease, of ICT investment in percentage of GDP or of total investment, observed from the beginning of the century, is not modified if we take into account the indirect ICT investment.
Keywords Technology, ICT, Investment
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Abstract Competition between two-sided platforms is shaped by the possibility of multihoming (i.e., some users joining both platforms). If initially both sides singlehome, each platform provides users on one side exclusive access to its users on the other side. If then one side multihomes, platforms compete on the singlehoming side and exert monopoly power on the multihoming side. This paper explores the allocative effects of such a change from single- to multihoming. Our results challenge the conventional wisdom, according to which the possibility of multihoming hurts the side that can multihome, while benefiting the other side. This in not always true, as the opposite may happen or both sides may benefit.
Keywords Multihoming, Competitive bottleneck, Platform competition, Two-sided markets, Network effects
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Abstract OBJECTIVES: This study assesses the change in premature mortality and in morbidity under the scenario of meeting the World Health Organization (WHO) global targets for non-communicable disease (NCD) risk factors (RFs) by 2025 in France. It also estimates medical expenditure savings because of the reduction of NCD burden. STUDY DESIGN: A microsimulation model is used to predict the future health and economic outcomes in France. METHODS: A 'RF targets' scenario, assuming the achievement of the six targets on RFs by 2025, is compared to a counterfactual scenario with respect to disability-adjusted life years and healthcare costs differences. RESULTS: The achievement of the RFs targets by 2025 would save about 25,300 (and 75,500) life years in good health in the population aged 25-64 (respectively 65+) years on average every year and would help to reduce healthcare costs by about €660 million on average per year, which represents 0.35% of the current annual healthcare spending in France. Such a reduction in RFs (net of the natural decreasing trend in mortality) would contribute to achieving about half of the 2030 NCD premature mortality target in France. CONCLUSIONS: The achievement of the RF targets would lead France to save life years and life years in good health in both working-age and retired people and would modestly reduce healthcare expenditures. To achieve RFs targets and to curb the growing burden of NCDs, France has to strengthen existing and implement new policy interventions.
Keywords Projection, Obesity, Non-communicable diseases, Smoking, Alcohol, Healthcare expenditure
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Abstract Digital information, particularly for online newsgathering and reporting, is an industry fraught with uncertainty and rapid innovation. Digital Information Ecosystems: Smart Press crosses academic knowledge with research by media groups to understand this evolution and analyze the future of the sector, including the imminent employment of bots and artificial intelligence. The book adopts an original and multidisciplinary approach to this topic: combining the science of media economics with the experience of a practicing journalist of a major daily newspaper. The result is an essential guide to the opportunities of the media to respond to a changing global digital landscape. Independent news reporting is vital in the contemporary democracy; the media must itself become a new smart press.
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Abstract Background: GPs are confronted with therapeutic dilemmas in treating patients with multimorbidity and/or polypharmacy when unfavourable medication risk–benefit ratios (RBRs) conflict with patients’ demands. Aim: To understand GPs’ attitudes about prescribing and/or deprescribing medicines for patients with multimorbidity and/or polypharmacy, and factors associated with their decisions. Design and setting: Cross-sectional survey in 2016 among a national panel of 1266 randomly selected GPs in private practice in France. Method: GPs’ opinions and attitudes were explored using a standardised questionnaire including a case vignette about a female treated for multiple somatic diseases, sleeping disorders, and chronic pain. Participants were randomly assigned one of eight versions of this case vignette, varying by patient age, socioprofessional status, and stroke history. Backward selection was used to identify factors associated with GPs’ decisions about drugs they considered inappropriate. Results: Nearly all (91.4%) responders felt comfortable or fairly comfortable deprescribing inappropriate medications, but only 34.7% decided to do so often or very often. In the clinical vignette, most GPs chose to discontinue symptomatic medications (for example, benzodiazepine, paracetamol/tramadol) because of unfavourable RBRs. When patients asked for ketoprofen for persistent sciatica, 94.1% considered this prescription risky, but 25.6% would prescribe it. They were less likely to prescribe it to older patients (adjusted odds ratio [AOR] 0.48, 95% confidence interval [CI] = 0.36 to 0.63), or those with a stroke history (AOR 0.55, 95% CI = 0.42 to 0.72). Conclusion: In therapeutic dilemmas, some GPs choose to prioritise patients’ requests over iatrogenic risks. GPs need pragmatic implementation tools for handling therapeutic dilemmas, and to improve their skills in medication management and patient engagement in such situations.
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Abstract On many two-sided platforms, users on one side not only care about user participation and usage levels on the other side, but they also care about participation and usage of fellow users on the same side. Most prominent is the degree of seller competition on a platform catering to buyers and sellers. In this paper, we address how seller competition affects platform pricing, product variety, and the number of platforms that carry trade.
Keywords Two-sided markets, Pricing, Platform competition, Network effects, Intermediation, Imperfect competition
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Abstract Attitude théorique et pratique, la philosophie économique est une démarche intellectuelle qui articule économie et philosophie. Mais comment la définir ? Et d’où vient l’intérêt grandissant que l’on constate depuis vingt ans ? Quelles ressources pluralistes mobilise-t-elle et comment s’est-elle constituée ? Quels rapports entretient-elle avec la théorie économique, l’histoire de la pensée et les philosophies morale et politique ? À ces questions, notamment, et en s’appuyant sur l’ouvrage collectif Philosophie économique. Cette introduction donne des réponses fondamentales, claires et précises.
Keywords Philosophie économique, Economie politique
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Abstract In this paper we investigate if government balanced-budget rules together with endogenous taxation may lead to aggregate instability in an endogenous growth framework. After highlighting the differences with the exogenous growth framework, we prove that under counter-cyclical consumption taxes, while there exists a unique balanced growth path, sunspot equilibria based on self-fulfilling expectations occur through a form of global indeterminacy. In addition, we argue that this result is empirically plausible for a large set of OECD countries and that it may also emerge with endogenous income taxes.
Keywords Sunspot equilibria, Self‐fulfilling expectation, Global indeterminacy, Time‐varying consumption tax, Endogenous growth
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Abstract We consider different approaches for assessing variable importance in clustering. We focus on clustering using binary decision trees (CUBT), which is a non-parametric top-down hierarchical clustering method designed for both continuous and nominal data. We suggest a measure of variable importance for this method similar to the one used in Breiman’s classification and regression trees. This score is useful to rank the variables in a dataset, to determine which variables are the most important or to detect the irrelevant ones. We analyze both stability and efficiency of this score on different data simulation models in the presence of noise, and compare it to other classical variable importance measures. Our experiments show that variable importance based on CUBT is much more efficient than other approaches in a large variety of situations.
Keywords Variable importance, Deviance, CUBT, Unsupervised learning, Variables ranking
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Abstract This paper provides direct evidence that learning about demand is an important driver of firms’ dynamics. We present a model of Bayesian learning in which firms are uncertain about idiosyncratic demand in each market and update their beliefs as noisy information arrives. Firms update their beliefs to a given demand shock more, the younger they are. We test and empirically confirm this prediction, using the structure of the model, together with exporter-level data, to identify demand shocks and the firms’ beliefs about future demand. Consistent with theory, we also find the learning process to be weakened in more uncertain environments.
Keywords Exports, Demand, Firm growth, Belief updating, Uncertainty
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Abstract We estimate the effect of the share of ethnic groups included in the central government on economic growth, distinguishing between democracies and autocracies in a panel of 41 Sub-Saharan African countries over the period from independence to 1999. We exploit evidence from the Ethnic Power Relations database, which categorises the politically relevant ethnic groups regarding access to state power. We take advantage of the time variation of political participation, using Fixed-Effects and Difference-GMM estimations. Our dynamic-panel growth models display a robust positive effect of the proportion of included groups in democracies. Such an effect is offset in autocracies, and the difference is often significant. This finding withstands the introduction of various controls, outlier tests, and specification checks. Our results support the view that institutional improvements must accompany the promotion of inclusiveness in low-income and weakly-institutionalised countries.
Keywords Institutions, Ethnic coalitions, Growth regressions
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Abstract A pure Hotelling game is a spatial competition between a finite number of players who simultaneously select a location in order to attract as many consumers as possible. In this paper, we study the case of a general distribution of consumers on a network generated by a metric graph. Because players do not compete on price, the continuum of consumers shop at the closest player’s location. If the number of sellers is large enough, we prove the existence of an approximate equilibrium in pure strategies, and we construct it.
Keywords Large games, Approximate Nash equilibria, Pure equilibria, Location games on networks, Hotelling games
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Abstract The interplay between growth and public debt is addressed considering a Barro-type (1990) endogenous growth model where public spendings are financed through taxes on income and public debt. The government has a target level of public debt relative to GDP, and the long-run debt-to-GDP ratio is used as a policy parameter. We show that when debt is a large enough proportion of GDP, two distinct balanced-growth paths (BGPs) may coexist, one being indeterminate. We exhibit two types of important trade-offs associated with self-fulfilling expectations. First, we show that the lowest BGP is always decreasing with respect to the debt-to-GDP ratio while the highest one is increasing. Second, we show that the highest BGP, which provides the highest welfare, is always locally indeterminate while the lowest is always locally determinate. Therefore, local and global indeterminacy may arise and self-fulfilling expectations appear as a crucial ingredient to understand the impact of debt on growth, welfare, and macroeconomic fluctuations. Finally, a simple calibration exercise allows to provide an understanding of the recent experiences of many OECD countries.
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Abstract This paper stresses a new channel through which global financial linkages contribute to the co‐movement in economic activity across countries. We show in a two‐country setting with borrowing constraints that international credit markets are subject to self‐fulfilling variations in the world real interest rate. Those expectation‐driven changes in the borrowing cost in turn act as global shocks that induce strong cross‐country co‐movements in both financial and real variables (such as asset prices, gross domestic product, consumption, investment, and employment). When firms around the world benefit from unexpectedly low debt repayments, they borrow and invest more, which leads to excessive supply of collateral and of loanable funds at a low interest rate, thus fueling a boom both at home and abroad. As a consequence, business cycles are synchronized internationally. Such a stylized model thus offers one way to rationalize both the existence of a world business‐cycle component, documented by recent empirical studies through dynamic factor analysis, and the factor's intimate link to global financial markets.
Keywords World interest rate, International co-movement, Self-fulfilling equilibria
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Abstract Why do some OECD countries have high levels of procedural formalism (PF) in the housing market? We provide an explanation based upon complementarities between the strength of social networks and the stringency of procedural formalism. The interest of social networks is that conflict resolution is independent from the law. When local agents belong to social networks whereas non-local agents do not, PF may facilitate housing search for locals at the expense of non-locals. To illustrate this mechanism we build a search-theoretic model of the housing market. The model emphasizes that the demand for PF occurs when the size of social networks is large. By simulations, we show that the support for PF increases with the size of social networks, the default probability on the rent and the proportion of non-local agents.
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