Publications

Résumé Workers' propensity to migrate to another local labor market varies a lot by occupation. We use the model developed by Schmutz and Sidibé (2019) to quantify the impact of mobility costs and search frictions on this mobility gap. We estimate the model on a matched employer-employee panel dataset describing labor market transitions within and between the 30 largest French cities for two groups at both ends of the occupational spectrum and find that: (i) mobility costs are very comparable in the two groups, so they are three times higher for blue-collar workers relative to their respective expected income; (ii) Depending on employment status, spatial frictions are between 2 and 3 times higher for blue-collar workers; (iii) Moving subsidies have little (and possibly negative) impact on the mobility gap, contrary to policies targeting spatial frictions; (iv) Mobility-enhancing policies have almost no impact on the unemployment gap.
Mots clés Occupation, Local labor markets, Migration, Spatial frictions, Mobility costs
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Résumé Background: In high-dimensional data analysis, the complexity of predictive models can be reduced by selecting the most relevant features, which is crucial to reduce data noise and increase model accuracy and interpretability. Thus, in the field of clinical decision making, only the most relevant features from a set of medical descriptors should be considered when determining whether a patient is healthy or not. This statistical approach known as feature selection can be performed through regression or classification, in a supervised or unsupervised manner. Several feature selection approaches using different mathematical concepts have been described in the literature. In the field of classification, a new approach has recently been proposed that uses the γ-metric, an index measuring separability between different classes in heart rhythm characterization. The present study proposes a filter approach for feature selection in classification using this γ-metric, and evaluates its application to automatic atrial fibrillation detection. Methods: The stability and prediction performance of the γ-metric feature selection approach was evaluated using the support vector machine model on two heart rhythm datasets, one extracted from the PhysioNet database and the other from the database of Marseille University Hospital Center, France (Timone Hospital). Both datasets contained electrocardiogram recordings grouped into two classes: normal sinus rhythm and atrial fibrillation. The performance of this feature selection approach was compared to that of three other approaches, with the first two based on the Random Forest technique and the other on receiver operating characteristic curve analysis. Results: The γ-metric approach showed satisfactory results, especially for models with a smaller number of features. For the training dataset, all prediction indicators were higher for our approach (accuracy greater than 99% for models with 5 to 17 features), as was stability (greater than 0.925 regardless of the number of features included in the model). For the validation dataset, the features selected with the y-metric approach differed from those selected with the other approaches; sensitivity was higher for our approach, but other indicators were similar. Conclusion: This filter approach for feature selection in classification opens up new methodological avenues for atrial fibrillation detection using short electrocardiogram recordings.
Mots clés Atrial fibrillation detection, Clinical decision making, Classification, Feature selection, Machine learning, Γ-metric, Machine learning, Feature selection, Clinical decision making, Classification, Atrial fibrillation detection, Y-metric
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Résumé We study price personalization in a two period duopoly with vertically differentiated products. In the second period, a firm not only knows the purchase history of all customers, as in standard Behavior Based Price Discrimination models, but it also collects detailed information on its old customers, using it to engage in price personalization. The analysis reveals that there exists a natural market for each firm, defined as the set of customers that cannot be poached by the rival in the second period. The equilibrium is unique, except when firms are ex-ante almost identical. In equilibrium, only the firm with the largest natural market poaches customers from the rival. This firm has highest profits but not necessarily the largest market share. Aggregate profits are lower than under uniform pricing. All consumers gain, total welfare is higher herein than under uniform pricing if firms’ natural markets are sufficiently asymmetric. The low quality firm chooses the minimal quality level and a quality differential arises, though the exact choice for the high quality depends upon the cost specification.
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Résumé Gilles Campagnolo a traduit et édité une œuvre majeure de la science économique, les Principes de Carl Menger, le prédécesseur et le maître, en Autriche, de Böhm-Bawerk, Mises, Hayek, Schumpeter, et de bien d’autres. En France son œuvre était connue de Rist, Colson, Perroux, Bousquet, mais depuis que les économistes français ne savent plus l’allemand elle est ignorée. En revanche, elle a bénéficié aux États-Unis d’une traduction et de l’émigration, dans les années trente, des grands économistes autrichiens vers les universités américaines. Gilles Compagnolo a bien voulu présenter à nos lecteurs cette savante et importante édition.
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Résumé Background Asthma affects over 330 million people worldwide. Timing of an asthma event is extremely important and lack of identification of asthma increases the risk of death. A major challenge for health systems is the length of time between symptom onset and care seeking, which could result in delayed treatment initiation and worsening of symptoms. Objective This study evaluates the utility of the internet search query data for the identification of the onset of asthma symptoms. Methods Pearson correlation coefficients between the time series of hospital admissions and Google searches were computed at lag times from 4 weeks before hospital admission to 4 weeks after hospital admission. An autoregressive integrated moving average (ARIMAX) model with an autoregressive process at lags of 1 and 2 and Google searches at weeks –1 and –2 as exogenous variables were conducted to validate our correlation results. Results Google search volume for asthma had the highest correlation at 2 weeks before hospital admission. The ARIMAX model using an autoregressive process showed that the relative searches from Google about asthma were significant at lags 1 (P
Mots clés Health information seeking, Symptoms, Asthma, Google queries, Digital epidemiology
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Résumé Detailed knowledge about hepatitis B virus (HBV) vaccination coverage and timeliness for sub-Saharan Africa is scarce. We used data from a community-based cross-sectional survey conducted in 2018–2019 in the area of Niakhar, Senegal, to estimate coverage, timeliness, and factors associated with non-adherence to the World Health Organisation-recommended vaccination schedules in children born in 2016 (year of the birth dose (BD) introduction in Senegal) and 2017–2018. Vaccination status was assessed from vaccination cards, surveillance data, and healthcare post vaccination records. Among 241 children with available data, for 2016 and 2017–2018, respectively, 31.0% and 66.8% received the BD within 24 h of birth (BD schedule), and 24.3% and 53.7% received the BD plus at least two pentavalent vaccine doses within the recommended timeframes (three-dose schedule). In logistic regression models, home birth, dry season birth, and birth in 2016 were all associated with non-adherence to the recommended BD and three-dose schedules. Living over three kilometres from the nearest healthcare post, being the firstborn, and living in an agriculturally poorer household were only associated with non-adherence to the three-dose schedule. The substantial proportion of children not vaccinated according to recommended schedules highlights the importance of considering vaccination timeliness when evaluating vaccination programme effectiveness. Outreach vaccination activities and incentives to bring children born at home to healthcare facilities within 24 h of birth, must be strengthened to improve timely HBV vaccination.
Mots clés Vaccination coverage, Vaccination timeliness, Senegal, Pentavalent vaccination, Hepatitis B vaccine, Birth dose vaccination
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Résumé Land is back. The increase in wealth in the second half of 20th century arose from housing and land. It should be taxed. We introduce land and housing structures in Judd’s standard setup: first best optimal taxation is achieved with a property tax on land and requires no tax on capital. With positive taxes on housing rents, a first best is still possible but with subsidies to rental housing investments, and either with differential land tax rates or with a tax on imputed rents. It can be taxed. Even absent land taxes, one can tax it indirectly and reach a Ramsey-second best still with no tax on capital and positive housing rent taxes in the steady-state. This result extends to the dynamics under restrictions on parameters.
Mots clés Capital, Wealth, Housing, Land, Optimal tax, First best, Second best
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Résumé Une stratégie financière doit aboutir à la rencontre d’une offre avec une demande de fonds en spécifiant les conditions spécifiques de cet échange et on doit naturellement s’attendre à ce que les temps de crise voient émerger des stratégies spécifiques. Pour apprécier la pertinence de ces stratégies nous rappelons les principes du financement des activités économiques en soulignant l’importance de la qualité de l’information des décideurs. Dans un deuxième temps nous nous penchons sur le rôle que l’État peut jouer en matière de financement (sections 2 et 3). Afin de correctement comparer les différentes stratégies de financement il est essentiel de prendre en compte les bénéfices mais aussi les coûts – directs mais, plus important encore, indirects – de ces stratégies (section 4). La prise en compte de tous ces paramètres conduit au plus grand scepticisme à l’égard des stratégies qui ont eu les préférences de nombreux États depuis le début de la crise de 2020.
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Résumé Austrian Economics and Public Choice are used to analyze the erratic administrative decision-making process during the Covid-19 crisis. Lockdowns policies had added a new page to the economic planning debate. The paper focus on the centralization/decentralization level of the decision and on the actors’ incentives. We use an Hayekian perspective on knowledge spreading in order to explain the crucial needs of human interactions. Lockdowns had pushed social organization toward more autarkist schemes. These measures confront heavily with the core organization of open societies, creating worry economic consequences without any proved positive effect on public healthcare.
Mots clés Knowledge, Austrian school, Public choice, Connaissance, École autrichienne, Choix public
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Résumé Preferences elicitation can be a challenging exercise for citizens participating in assessment surveys. It is even more challenging when it comes to complex and unfamiliar ecosystems and the threatened ecosystem services they provide. Making people aware of the characteristics of the ecosystem services being valued is determinant for the assessment process. We investigated the impact of familiarity and academic information supply on people's preferences for twenty selected ecosystem services of French Mediterranean coastal lagoons. The results show that regardless of familiarity and information supply, there is a strong consensus about the highest importance of regulation and maintenance ecosystem services as well as environmental education and research opportunity ecosystem services. By contrast, nine of the cultural ecosystem services, together with two provisioning ecosystem services showed heterogeneous preferences among the different citizen groups. Using a combination of descriptive and inferential statistics these eleven ecosystem services split up into three clusters characterized as (i) contemplative leisure, (ii) heritage, and (iii) consumptive activities. Familiarity and academic information supply had a strong impact on the preferences for these three clusters of ecosystem services.
Mots clés Preference elicitation, Coastal lagoons, Citizens&#039, workshop, Paternalism, Cultural ecosystem services CES, Veil of ignorance
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Résumé This chapter discusses whether the Middle East and North African (MENA) countries are prone to be cursed or blessed by their natural resources endowments. It thus reviews the literature on the resource curse theory. The existence of a resource curse is discussed and arguments against advocates of the resource curse are presented. Then, the resource curse transmission channels are presented. Finally, we present to what extent MENA countries are affected by the curse, drawing on existing literature as well as empirical data. The (scarce) literature shows that a resource curse may be underway in MENA economies. Broadly speaking, this literature often argues that the curse could be turned into a blessing through institutional improvements. The empirical data presented in this chapter tend to confirm this view. They show that the economic development of resource-rich MENAs has not been translated into human progress and has been largely non-inclusive. These results are stronger when the resource rent per capita is larger. Finally, the average institutional quality in resources-rich MENA countries appears to be lower than the average institutional quality in resources-poor MENA economies, suggesting some room for an institutional resource curse.
Mots clés Institutions, Economic development, MENA, Natural resources curse
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Résumé We study infinitely repeated games in which players are limited to subsets of their action space at each stage—a generalization of asynchronous games. This framework is broad enough to model many real-life repeated scenarios with restrictions, such as portfolio management, learning by doing and training. We present conditions under which rigidity in the choice of actions benefits all players in terms of worst-case equilibrium payoff and worst-case payoff. To provide structure, we exemplify our result in a model of a two-player repeated game, where we derive a formula for the worst-case payoff. Moreover, we show that in zero-sum games, lack of knowledge about the timing of the revision can compensate for inability to change the action.
Mots clés Exogenous timing, Commitment, Worst-case payoffs, Rational minimax, Asynchronous games
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Résumé We examine the impact of balanced-budget labor income taxes on the existence of expectation-driven business cycles in a two-sector version of the Schmitt-Grohé and Uribe (SGU) [(1997) Journal of Political Economy 105, 976–1000] model with constant government expenditures and counter-cyclical taxes. Our results show that the destabilizing impact of labor income taxes strongly depends on the capital intensity difference across sectors. Local indeterminacy is indeed more likely when the consumption good sector is capital intensive, as the minimal tax rate decreases, and less likely when the investment good sector is capital intensive, as the minimal tax rate increases. The implication of this result can be quantitatively significant. Indeed, when compared to SGU, local indeterminacy can be either completely ruled out for all OECD countries when the investment good is sufficiently capital intensive or drastically improved, delivering indeterminacy for a larger set of OECD countries, if the consumption good is sufficiently capital intensive. Focusing however on recent estimates of the sectoral capital shares corresponding to the empirically plausible case of a capital intensive consumption good, we find that there is a significant increase of the range of economically relevant labor tax rates (from a minimum tax rate of 30% to 24.7%) for which local indeterminacy arises with respect to the aggregate formulation of SGU.
Mots clés Aggregate instability, Local indeterminacy, Expectations-driven fluctuations, Laboreincome taxes, Balanced-budget rule, Infinite-horizon two-sector model, Capital intensity difference
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Résumé BACKGROUND: Opinion polls on vaccination intentions suggest that COVID-19 vaccine hesitancy is increasing worldwide; however, the usefulness of opinion polls to prepare mass vaccination campaigns for specific new vaccines and to estimate acceptance in a country's population is limited. We therefore aimed to assess the effects of vaccine characteristics, information on herd immunity, and general practitioner (GP) recommendation on vaccine hesitancy in a representative working-age population in France. METHODS: In this survey experiment, adults aged 18-64 years residing in France, with no history of SARS-CoV-2 infection, were randomly selected from an online survey research panel in July, 2020, stratified by gender, age, education, household size, and region and area of residence to be representative of the French population. Participants completed an online questionnaire on their background and vaccination behaviour-related variables (including past vaccine compliance, risk factors for severe COVID-19, and COVID-19 perceptions and experience), and were then randomly assigned according to a full factorial design to one of three groups to receive differing information on herd immunity (>50% of adults aged 18-64 years must be immunised [either by vaccination or infection]; >50% of adults must be immunised [either by vaccination or infection]; or no information on herd immunity) and to one of two groups regarding GP recommendation of vaccination (GP recommends vaccination or expresses no opinion). Participants then completed a series of eight discrete choice tasks designed to assess vaccine acceptance or refusal based on hypothetical vaccine characteristics (efficacy [50%, 80%, 90%, or 100%], risk of serious side-effects [1 in 10 000 or 1 in 100 000], location of manufacture [EU, USA, or China], and place of administration [GP practice, local pharmacy, or mass vaccination centre]). Responses were analysed with a two-part model to disentangle outright vaccine refusal (irrespective of vaccine characteristics, defined as opting for no vaccination in all eight tasks) from vaccine hesitancy (acceptance depending on vaccine characteristics). FINDINGS: Survey responses were collected from 1942 working-age adults, of whom 560 (28·8%) opted for no vaccination in all eight tasks (outright vaccine refusal) and 1382 (71·2%) did not. In our model, outright vaccine refusal and vaccine hesitancy were both significantly associated with female gender, age (with an inverted U-shaped relationship), lower educational level, poor compliance with recommended vaccinations in the past, and no report of specified chronic conditions (ie, no hypertension [for vaccine hesitancy] or no chronic conditions other than hypertension [for outright vaccine refusal]). Outright vaccine refusal was also associated with a lower perceived severity of COVID-19, whereas vaccine hesitancy was lower when herd immunity benefits were communicated and in working versus non-working individuals, and those with experience of COVID-19 (had symptoms or knew someone with COVID-19). For a mass vaccination campaign involving mass vaccination centres and communication of herd immunity benefits, our model predicted outright vaccine refusal in 29·4% (95% CI 28·6-30·2) of the French working-age population. Predicted hesitancy was highest for vaccines manufactured in China with 50% efficacy and a 1 in 10 000 risk of serious side-effects (vaccine acceptance 27·4% [26·8-28·0]), and lowest for a vaccine manufactured in the EU with 90% efficacy and a 1 in 100 000 risk of serious side-effects (vaccine acceptance 61·3% [60·5-62·1]). INTERPRETATION: COVID-19 vaccine acceptance depends on the characteristics of new vaccines and the national vaccination strategy, among various other factors, in the working-age population in France. FUNDING: French Public Health Agency (Santé Publique France).
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Résumé We study the joint determination of optimal investment and optimal depollution in a spatiotemporal framework where pollution is transboundary. Pollution is controlled at a global level. The regulator internalizes that: (i) production generates pollution, which is bad for the wellbeing of population, and that (ii) pollution flows across space driven by a diffusion process. We solve analytically for the optimal investment and depollution spatiotemporal paths and characterize the optimal long-term spatial distribution when relevant. We finally explore numerically the variety of optimal spatial distributions obtained using a core/periphery model where the core differs from the periphery either in terms of input productivity, depollution efficiency, environmental awareness or self-cleaning capacity of nature. We also compare the distributions with and without diffusion. Key aspects in the optimal policy of the regulator are the role of aversion to inequality, notably leading to smoothing consumption across locations, and the control of diffusive pollution adding another smoothing engine.
Mots clés Decision analysis, Pollution control, Geography, Transboundary pollution, Infinite dimensional optimal control problems
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Résumé We show that a majoritarian relation is, among all conceivable binary relations, the most representative of the profile of preferences from which it emanates. We define ''the most representative'' to mean that it minimizes the sum of distances between itself and the preferences in the profile for a given distance function. We identify a necessary and sufficient condition for such a distance to always be minimized by a majoritarian relation. This condition requires the distance to be additive with respect to a plausible notion of compromise between preferences. The well-known Kemeny distance does satisfy this property, along with many others. All distances that satisfy this property can be written as a sum of strictly positive weights assigned to the ordered pairs of alternatives by which any two preferences differ.
Mots clés Majority, Distance, Binary Relation, Aggregation
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Résumé Our analysis of US state-level data on an annual frequency, from 1976 to 2008, sheds new light on a plausible causal link between infrastructure investments, namely public spending on highways, and income inequality. This causal relationship is drawn out using the number of seats in the US House of Representatives Committee on Appropriations (HRCA) as an instrument to identify quasi-random variations in state-level spending on highways. An exogenous pattern which emerges when a state gains an additional member to the HRCA is that it is allocated with new federal grants. This increase in federal transfers for infrastructure financing results in slashing of expenditures on highways and a crowding-out effect of federal funding for state investments on highways. Spending cuts on highways produced by a new HRCA member being attained by a state can unwittingly cause income inequality to rise over a short 2-year time horizon. Similar challenges with decentralized development to finance infrastructure via federal transfers to state and sub-national governments may be encountered by other industrially advanced, emerging and low-income developing economies. US data over the mentioned period reveal a strong positive correlation with state spending on highways and wages paid for construction jobs. Suggestive evidence indicates that the construction sector also plays an important role in the transmission channel from a rise in state spending on highways to lowering income inequality, albeit during specific intervals, as opposed to on a long-term basis.
Mots clés US state panel data, Public infrastructure, Instrument variable, Income inequality, Highways
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Résumé We propose a structural econometric model that incorporates altruism towards other household members into the willingness to pay for a public good. The model distinguishes preferences for public good improvements for oneself from preferences for improvements for other household members. We test for three different types of altruism - ‘pure self-interest’, ‘pure altruism’ and ‘public-good-focused non-pure altruism’. Using French contingent valuation data regarding air quality improvements, we find positive and significant degrees of concern for children under the age of 18, which are explained by determinants related to health and subjective air quality assessment. All other forms of pure or air-quality-focused altruism within the family are insignificant, including for children over 18, siblings, spouses, and parents. This result suggests that benefit estimates that do not consider altruism could undervalue improvements in air quality in France.
Mots clés Willingness to pay, Contingent valuation, Field experiment, Familial altruism, Air pollution
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Résumé This paper analyses the effects of flow pollution implied by the use of necessary non-renewable resources, fossil fuel for example, on overlapping generations (OLG) economies. Notably, it shows that, on the balanced growth path, flow pollution reduces the (negative) resources contribution to growth and increases resources conservation, capital accumulation, and growth. Flow pollution thus increases the ability of an economy to sustain a non-decreasing consumption path. Some of the results are due to (or magnified by) the OLG structure of the economy. In addition, the paper highlights the need for public intervention and shows that the optimal allocation may be decentralized using a tax on resources use and transfers.
Mots clés Overlapping generations, Pollution, Growth, Non-renewable Resources
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