Publications

Résumé Sub-Saharan Africa's hepatitis B virus (HBV) burden is primarily due to infection in infancy. However, data on chronic HBV infection prevalence and associated risk factors in children born post-HBV vaccination introduction are scarce. We estimated hepatitis B surface antigen (HBsAg) prevalence and risk factors in Senegalese children born during the HBV vaccination era. In 2018-2019, a community-based cross-sectional survey was conducted in Senegal among children born between 2004 and 2015 (ie after the three-dose HBV vaccine series was introduced (2004) but before the birth dose's introduction (2016)). HBsAg-positive children were identified using dried blood spots. A standardized questionnaire collected socioeconomic information. Data were age-sex weighted and calibrated to be representative of children living in the study area. Risk factors associated with HBsAg positivity were identified using negative binomial regression. Among 1,327 children, 17 were HBsAg-positive (prevalence = 1.23% (95% confidence interval [CI] 0.61-1.85)). Older age (adjusted incidence-rate ratio [aIRR] 1.31 per one-year increase, 95% CI 1.10-1.57), home vs healthcare facility delivery (aIRR 3.55, 95% CI 1.39-9.02), stitches (lifetime) (aIRR 4.79; 95% CI 1.84-12.39), tattoos (aIRR 8.97, 95% CI 1.01-79.11) and having an HBsAg-positive sibling with the same mother (aIRR 3.05, 95% CI 1.09-8.57) were all independently associated with HBsAg positivity. The low HBsAg prevalence highlights the success of the Senegalese HBV vaccination program. To further reduce HBV acquisition in children, high-risk groups, including pregnant women and siblings of HBsAg-positive individuals, must be screened. Vital HBV infection prevention measures include promoting delivery in healthcare facilities, and increasing awareness of prevention and control procedures.
Mots clés Child, Hepatitis B, Prevalence, Risk factors, Senegal
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Résumé This paper documents the determinants of real oil price in the global market based on an empirical model embedding transitory and permanent shocks. We find evidence of significant differences in the propagation mechanisms of transitory versus permanent disturbances, pointing to the importance of disentangling their distinct effects. Permanent supply shocks are found to be very influential in driving oil price fluctuations.
Mots clés Bayesian estimationKalman lteringNarrative analysisOil marketVector autoregressions
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Résumé Cette étude a pour objectif d’évaluer différents modes de financement de la couverture santé universelle au Sénégal. La méthode utilisée, la micro-simulation, permet d’examiner l’impact de différents scenarii sur les consommations des ménages ainsi que sur les dépenses publiques. Les résultats montrent que la généralisation d’une assurance-maladie à l’ensemble de la population, associée à une réduction des coûts directs des soins, augmenterait les consommations de soins des Sénégalais, améliorant donc leur accès aux services de santé. Néanmoins, une telle généralisation serait coûteuse pour les finances publiques. Pour limiter les coûts supportés par le gouvernement, l’augmentation du taux d’imposition sur la consommation et de la prime de contribution à l’assurance-maladie serait utile et permettrait de ramener les finances publiques à l’équilibre.
Mots clés Sahel, Coûts directs des soins, Finances publiques, Micro-simulation, Couverture sante universelle
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Résumé Knightian uncertainty represents a situation in which it is no longer possible to form expectations about future events. We propose a method to directly measure Knightian uncertainty. Our approach relies on firm-level data and measures the share of firms that do not formalize expectations about their future demand. We construct the Knightian Uncertainty Indicator for Switzerland and show that the indicator is able to identify times of high uncertainty. We evaluate the indicator by comparing it to established uncertainty measures. We find that a one standard deviation innovation of the Knightian Uncertainty Indicator leads to a negative and persistent reduction of investment.
Mots clés Business survey, Measurement, Uncertainty, Knight
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Résumé Many countries are reallocating tasks and powers to more central levels of government. To identify centralization’s welfare effects, I use a difference-in-differences design that relies on time and cross-cantonal variation in the implementation of centralization reforms in Switzerland. I find that centralization provokes significant decreases in residents’ life satisfaction. I identify one mechanism driving the effect, namely the procedural disutility that individuals experience from having less influence over the formulation of political decisions. This effect is largest among individuals with higher expected benefits from being involved in the political decision process, with detrimental effects on local political participation.
Mots clés Political participation, Procedural utility, Life satisfaction, Centralization
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Résumé Comment mesurer le plus finement possible l'accélération ou la décélération d'une épidémie ?
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Résumé Does giving taxpayers a voice over the destination of tax revenues lead to more honest income declarations? Previous experiments have shown that giving participants the opportunity to select the organization that receives their tax funds tends to increase tax compliance. The aim of this paper is to assess whether this increase in compliance is induced by the sole fact of giving subjects a choice—a “direct democracy effect”. To that aim, we ask participants to a tax evasion game to choose, in a collective or individual choice setting, between two very similar organizations which provide the same social (ecological) benefits. We elicit compliance for both organizations before the choice is made so as to control for the counter-factual compliance decision. We find that democracy does not increase compliance, and even observe a slight negative effect—in particular for women. Our results confirm the existence of a commitment effect of democracy, leading to favor more the selected organization when it was actively chosen. The commitment effect of democracy is however not enough to overcome the decrease in the level of compliance. Thanks to response times data, we show that prior choice on similar options as compared to a purely random selection weakens the preference for honesty. One important field application of our results is that democracy in tax spending must offer real choices to tax payers to improve compliance.
Mots clés Commitment, Direct democracy effect, Voting, Tax evasion game
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Résumé La part de l'aide humanitaire croît dans l'aide totale. Or les acteurs impliqués restent peu étudiés. Cet article documente la fragmentation de l'aide à un double niveau : celui des donneurs et celui des acteurs de terrains. Le jeu de délégation entre les deux peut réduire les effets négatifs de la fragmentation de l'aide. À partir de trois études de cas, le lien entre fragmentation, délégation et efficacité de l'aide humanitaire est illustré et les coûts et bénéfices potentiels
Mots clés Delegation, Fragmentation, Implementing agency, Donor, Humanitarian aid, Delegation, Intermédiaires, Donneurs, Fragmentation, Aide humanitaire
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Résumé This paper proposes two dominance criteria for evaluating education systems described as joint distributions of the pupils’ cognitive skill achievements and family backgrounds. The first criterion is the smallest transitive ranking of education systems compatible with three elementary principles. The first principle requires the favorable recording of any improvement in the cognitive skill of a child with a given family background . The second principle demands that any child’s cognitive skill be all the more favourably appraised as the child is coming from an unfavourable background. The third principle states that when two different skills and family backgrounds are allocated between two children, it is preferable that the high skill be given to the low background child than the other way around. Our second criterion adds to the three principles the elitist requirement that a mean-preserving spread in the skills of two children with the same background be recorded favorably. We apply our criteria to the ranking of education systems of 43 countries, where we measure cognitive skills by PISA score in mathematics and famly background by the largest of the two parents’International Socio Economic Index. Our criteria conclusively compare about 19% of all the possible pairs of countries.
Mots clés Dominance, Opportunities, Maths scores, International comparisons, Family background, Inequality, Education
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Résumé This study examines a specific class of common-pool resources whereby rivalry is not characterized by competition for the resource stock. Artesian aquifers are a typical example of such resources since the stock never depletes, even when part of the resource is extracted. We first propose a dynamic model to account for the relevant features of such aquifers such as the water pressure and well yield and characterize the corresponding dynamics. We then compare the social optimum with the private exploitation of an open-access aquifer. The comparison of these two equilibria highlights the existence of a new source of inefficiency. In the long run, this so-called pressure externality results in an additional number of wells for the same water consumption, thereby raising costs. Finally, we characterize a specific stock-dependent tax to neutralize the pressure externality.
Mots clés Dynamic optimization, Public regulation, Optimal management, Externality, Common-pool resource
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