Publications

Résumé Panel VAR methodology is used in this study to empirically evaluate the effects of natural disasters and state fragility on economic and financial dimensions in developing countries such as GDP per capita, banking and financial system deposits, banks’ Z-scores, and non-performing loans. Results based on three panels of up to 66 countries and 17 years of annual data indicate that natural disasters and state fragility may cause significant economic and financial disruption in low-income and middle-income countries. Shocks from natural disasters seem to be temporary and detrimental only to non-performing loans, while shocks from state fragility appear to be permanent and to create detrimental economic and financial feedback loops.
Mots clés State fragility, Natural disasters, GDP per capita, Banking stability
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Résumé In familiar models, a decrease in the friction facing mobile factors (e.g., lowering their adjustment costs) increases a coordination problem, leading to more circumstances where there are multiple equilibria. We show that a decrease in friction can decrease coordination problems when a production externality arises from a changing stock, e.g. of pollution or knowledge. In general, the relation between the amount of friction that mobile factors face and the likelihood of multiple equilibria is non-monotonic.
Mots clés Costs of adjustment, Multiple equilibria, Factor reallocation, Intersectoral migration, Learning-by-doing, Coordination games, Cross-sectoral pollution
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Résumé Mainstream research has rationalized China’s stock market on the basis of paradigms such as the institutional approach, the efficient market hypothesis, and corporate valuation principles. The deviations from such paradigms have been analyzed as puzzles of China’s stock market. Girardin and Liu explore to what extent, in the perspective of Chinese cultural and historical characteristics, far from being puzzles, these 'deviations’ are rather the symptoms of a consistent strategy for the design, development and regulation of a government-dominated financial system. This book will help investors, observers and researchers understand the hidden logic of the design and functioning of China’s modern stock market, taking a political economy view.
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Résumé Using a simple decision-theoretic approach, we formalize how agents with different kinds of intrinsic motivations react to the introduction of monetary incentives. We contend that empirical results supporting the existence of a crowding-out effect under various legal procedures hide a more complex reality, where some individuals contribute thanks to these additional monetary incentives while others reduce their contributions. Our approach allows us to study the theoretical ability of the self selection mechanism (Mellström and Johannesson in J Eur Econ Assoc 6:845–863, 2008; Beretti et al. in Kyklos 66(1):63–77, 2013) to reduce the likelihood to backfire against the cause it is meant to promote. This mechanism consists of a monetary payment for the pro-social behavior and it offers agents the choice to either keep the money for themselves or to direct it to a charity. We show that this legal procedure dominates others more classical procedures because it taps wisely into the motivational heterogeneity of individuals. It uses a self-selection mechanism to match adequate monetary incentives with individuals’ types regarding intrinsic motivations. It may even turn a situation subject to crowding-out into a crowding-in outcome.
Mots clés Environmental Regulation, Moral motivation, Heterogeneity, Crowding-out
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Résumé Young Europeans experience high unemployment rates, job instability, and late emancipation. Meanwhile, they do not support reforms weakening protection on long-term contracts. In this paper, we suggest a possible rationale for such reform distaste. When the rental market is strongly regulated, landlords screen applicants with regard to their ability to pay the rent. Protecting regular jobs offers a second-best technology to sort workers, thereby increasing the rental market size. We provide a model where nonemployed workers demand protected jobs despite unemployment and the share of short-term jobs increases, whereas the individual risk of dismissal is unaffected. Our theory can be extended to alternative risks and markets involving correlated risks and commitment under imperfect information.
Mots clés Rent default, Screening, Labor market dualism
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Résumé In this paper, we consider competitive polluting firms that outsource their abatement activity to an upstream imperfect competitive eco-industry to comply with environmental regulation. In this case, we show that an usual environmental policy based on a Pigouvian tax or a pollution permit market reaches the first-best outcome. The main intuition is based on the idea that purchasing pollution reduction services instead of pollution abatement inputs modifies for each potential tax rate (or out of the equilibrium permit price) the nature of the arbitrage between pollution and abatement. This induces a demand for abatement services which is, at least partially, strongly elastic and therefore strongly reduces upstream market power. This argument is first illustrated with an upstream monopoly selling eco-services to a representative polluting firm under a usual Pigouvian tax. We then progressively extend the result to permit markets, heterogeneous downstream polluters and heterogeneous upstream Cournot competitors. JEL Codes: Q58, D43
Mots clés Abatement Outsourcing, Imperfect competition, Eco-industry, Environmental Regulation
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Résumé This paper studies the optimal growth path of a natural resource-rich country, which can borrow from international financial markets. I explore to what extent international borrowing can overcome resource scarcity in a small open economy, in order to have sustainable growth. First, a benchmark model with a constant interest rate and technical progress is set up to see if the economy's growth can be sustainable in the long run. Secondly, the case of a debt elastic interest rate is analysed. The main finding of this paper is that borrowing on international capital markets does not permit sustainable growth for a country with exhaustible natural resources, when the interest rate is constant. Nevertheless, when the interest rate is endogenized, the consumption growth rate can be positive before declining.
Mots clés Financial markets, Exogenous growth, Exhaustible natural resources
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Résumé We study the determination of public tuition fees through majority voting in a vertical differentiation model where agents' returns on educational investment differ and public and private universities coexist and compete in tuition fees. The private university offers higher educational quality than its competitor, incurring higher unit cost per trained student. The tuition fee for the state university is fixed by majority voting while that for the private follows from profit maximization. Then agents choose to train at the public university or the private one or to remain uneducated. The tax per head adjusts in order to balance the state budget. Because there is a private alternative, preferences for education are not single-peaked and no single-crossing condition holds. An equilibrium is shown to exist, which is one of three types: high tuition fee (the “ends” are a majority), low tuition fee (the “middle” is a majority), or mixed (votes tie). The cost structure determines which equilibrium obtains. The equilibrium tuition is either greater (majority at the ends) or smaller (majority at the middle) than the optimal one.
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Résumé We challenge the accepted wisdom of a global secular decline in the labor share. A simple theoretical model is proposed to highlight the main factors of change in the labor share. We document three issues in the existing literature: (i) starting periods for the empirical analysis; (ii) accounting for self employment; and (iii) accounting for residential real estate income. An empirical analysis is carried out since the post war period for France and the United States, and since the 1990s for ten developed countries and on a six country “euro area”. How the three questions above are addressed is crucial to the diagnosis. When the biases that may arise with the three issues mentioned above are eliminated, the labor share in the market sector does not show a general downward or upward trend. The choice of period has a huge impact, as does the treatment of real estate services, whose inclusion or not in the value added can result in significantly different trends.
Mots clés Value added sharing, Labor cost, Labor share
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Résumé This paper is devoted to new versions of Ekeland’s variational principle in set optimization with domination structure, where set optimization is an extension of vector optimization from vector-valued functions to set-valued maps using Kuroiwa’s set-less relations to compare one entire image set with another whole image set, and where domination structure is an extension of ordering cone in vector optimization; it assigns each element of the image space to its own domination set. We use Gerstewitz’s nonlinear scalarization function to convert a set-valued map into an extended real-valued function and the idea of the proof of Dancs-Hegedüs-Medvegyev’s fixed-point theorem. Our setting is applicable to dynamic processes of changing jobs in which the cost function does not satisfy the symmetry axiom of metrics and the class of set-valued maps acting from a quasimetric space into a real linear space. The obtained result is new even in simpler settings.
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Résumé The demand for weather-sensitive products, such as beverages, ice creams, or chocolate varies with changes in temperature. Yet, retailers lack a framework to adapt the marketing mix elements, such as price and advertising, in line with such changes. We provide a theoretical framework to fill this gap by developing an analytical model to derive the optimal marketing mix when product demand depends on temperature. The model prescribes how price and advertising for different demand characteristics should be set following a temperature change. Integrating the temperature element in the marketing mix offers an original profit-enhancing strategy.
Mots clés Marketing mix, Weather-sensitivity, Temperature, Advertising, Pricing
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Résumé Après la publication du Soi et son cerveau (Rue d’Ulm, oct. 2018), ce volume vient clore la publication des œuvres de Popper en langue française (à l’exception de textes datés consacrés quasi exclusivement à la physique quantique). Les écrits de jeunesse montrent la genèse de l’œuvre poppérienne dans une Vienne éducatrice et matrice de savoirs neufs (réforme scolaire, néopsychologie, Cercle de Vienne) au sein d’un milieu cosmopolite progressiste, et l’environnement d’un penseur enthousiaste dans ses premières réalisations. Ils traitent aussi bien de la relation élève-enseignant que du processus de mémorisation, de l’idée de patrie que de l’« expérience vécue de la règle ».
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Résumé A principal targets agents organized in a network of local complementarities, in order to increase the sum of agents' effort. We consider bilateral public contracts à la Segal (1999). The paper shows that the synergies between contracting and non-contracting agents deeply impact optimal contracts: they can lead the principal to contract with a subset of the agents, and to refrain from contracting with central agents.
Mots clés Network, Synergies, Aggregate effort, Optimal group targeting
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Résumé We provide with an optimal growth spatio-temporal setting with capital accumulation and diffusion across space in order to study the link between economic growth triggered by capital spatio-temporal dynamics and agglomeration across space. We choose the simplest production function generating growth endogenously, the AK technology but in sharp contrast to the related literature which considers homogeneous space, we derive optimal location outcomes for any given space distributions for technology (through the productivity parameter A) and population. Beside the mathematical tour de force, we ultimately show that agglomeration may show up in our optimal growth with linear technology, its exact shape depending on the interaction of two main effects, a population dilution effect versus a technology space discrepancy effect.
Mots clés Growth, Infinite dimensional optimal control problems, Heterogeneous and continuous space, Agglomeration, Cap- ital mobility
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Résumé Dans Économie politique et philosophie chez Steuart et Hegel (1963), Paul Chamley examine l’intérêt que Hegel prit tôt pour l’économie. Il le rapporte à l’influence sur Hegel de la lecture, à Francfort, de l’Enquête publiée par James Steuart, ouvrage (aujourd’hui trop négligé) qui précéda La Richesse des nations d’Adam Smith. Quels thèmes majeurs Hegel y puisa-t-il ? Existe-t-il d’ailleurs une « économie hégélienne » per se ? Les notions hégéliennes en ce domaine sont-elles d’un bloc ? Outre l’effet du livre de Steuart, s’exercèrent les influences du caméralisme germanique traditionnel et du classicisme britannique naissant. Il faut donc montrer plus de circonspection que Chamley n’en eut et cet essai réévalue les vues de Hegel sur l’économie dans son époque.
Mots clés Steuart Sir James, Smith Adam, Hegel GWF, Chamley Paul, German Cameralists, Smith Adam, Steuart Sir James, Hegel GWF, Chamley Paul, Caméralisme allemand
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Résumé Background: In France, Health Regional Agencies (HRA) have to elaborate a Public Health Plan for the 5 coming years. For estimating future population health needs and associated costs to adapt the health services on the regional territory, the HRA in southeastern France requested a prospective analysis, based on demographic and epidemiologic scenarios about major chronic diseases, to evaluate future trends. Methods: Six chronic diseases were selected: diabetes (1 or 2), cardiovascular diseases, respiratory diseases, cancers, neurological diseases and dementia. We used medico-administrative data from the National health insurance fund, and adapted algorithms to identify people with these diseases. We calculated prevalence rates according to gender and age and used two alternative scenarios (a constant one, and a trend-based one) to estimate the number of people with chronic diseases in 2023 and 2028, starting in 2016. We also estimated future healthcare costs according a constant and a trend-based scenario. Results: The algorithms detect reasonable rates of disease compared to official rates available for 2016. Due to demographic (ageing) and/or epidemiologic trends, the number of people with chronic diseases will highly increase during the next ten years in the South of France region. For instance, between 2016 and 2028, there will be from 15% to 20% more people with diabetes. Associated costs will also be higher (+33% between 2016 and 2028), especially those granted to nursing care (+40%). Conclusions: Burden of diseases and health expenditures are going to increase in the future. Projections are needed to help policymakers anticipating the required health services adaptation. Medico-administrative database are an invaluable source of data to do so. The next step of this project will consist in estimating those trends for smaller geographical areas.
Mots clés Type 2, Cancer, Aging, Cardiovascular diseases, Diabetes mellitus, Nervous system disorders, Chronic disease, Dementia, Cost of illness, Demography, Geographic area, Health care costs, Population health, Fiberoptic examinations anoscopy high resolution, Gender, Public health medicine, Nursing care, Respiration disorders, Health insurance, Health services, Health expenditures
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Résumé Background: Each year, almost 400,000 new individuals are diagnosed with cancer in France and nearly half of them are in the working age. The disease was found to have a negative impact on professional life, especially for the most vulnerable cancer survivors. Literature reviews have pointed out the lack of studies focusing on the evaluation of interventions. In France, workstation layouts are recommended by the French law, but not mandatory to facilitate return to work. The aim of this study was to explore the effect of having a workstation layout after a cancer diagnosis on maintenance in employment five years after diagnosis. Methods: We used the French VICAN survey carried out in 2015/2016 on living conditions five years after a cancer diagnosis. Using propensity score matching, we matched two subsamples (with and without workstation layout) to investigate the effect of workstation layout taking into account the characteristics associated with the access to these arrangements. Results: Among the 1,514 individuals aged between 18 and 54 at diagnosis and employed in a salaried job at this time, three in five (61.2%) had a workstation layout within the five years following the diagnosis: 35.5% had a position type layout, 41.5% had a schedule layout, and 49.2% had a working time layout. Among those who had a workstation layout, 89.7% were still in employment five years after diagnosis against only 77.8% of those who did not so (p.value
Mots clés Feelings, Living arrangements, Cancer diagnosis, Cancer survivors, Job reentry, Statutes and laws, Diagnosis, Workplace, Survivors, Employment, Chronic disease, Cancer
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