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When You Can't Afford to Wait for a Job: The Role of Time Discounting for Own-Account Workers in Developing Countries
No full textInternational audienceFrictional labor markets impose a fundamental trade-off: individuals may work on their own at any time, but can only take a potentially better-paid wage job after spending some time looking for it, suggesting that intertemporal considerations affect how people choose their occupation. We formalize this intuition under the job search framework and show that a sufficiently high subjective discount rate can justify the choice for own-account work even when it pays less than wage work. With this simple model, we estimate the lowest discount rate that is consistent with the occupational choice of urban own-account workers in Brazil. We find that at least 65 percent of those workers appear to discount the future at rates superior to those available in the formal credit market, which suggests constrained occupational choice.Finally, we show that our estimated lower bound of the time preference is positively associated with food, clothing, and housing deprivation.</p
Distributing a Sane Beverage? The Social Differentiation of Access to Water in Paris
No full textInternational audienceWater management depends on both the physical and social structures of large cities. In Paris, these elements interacted to limit and constrain access to water for large segments of the population for long periods of time. The very unequal distribution of property in the city is central to understanding water regimes in Paris and their evolution over time. This article analyzes the evolution of water systems in Paris from the mid-nineteenth century to the mid-twentieth century, considering access to water (and its quality) as well as the provision of sewers to remove waste soiled materials. Important social variations in the modalities of access to water within the city persisted for a long time. They were a consequence of choices made in organizing the distribution of water in the city
Thermal noise reduction in ion-beam sputtered HfO2:Ta2O5 thin films via high-temperature treatment
No full textInternational audienc
Failure Detection Under Sensing Uncertainty in Vehicular Systems
No full textInternational audienceThe advancement of autonomous vehicles depends on the integration of sophisticated sensors that perceive their environment in real-time. However, these sensors are prone to uncertainties that, if not properly managed, could undermine the vehicle’s decision-making process and elevate road safety risks. In response to this challenge, we present an embeddable solution designed to filter uncertain data using a machine learning model. Our solution not only resists to inconsistencies in sensor data but also quantifies the degree of anomaly in sensor outputs. This capability is essential for enabling effective predictive maintenance by identifying potentially failing systems before they compromise the overall performance. Through simulations, we demonstrate that the anomaly system detector enhances the vehicle’s resilience against discordant data
Monitoring plastic debris in urban stormwater: fluxes and management issues
No full textInternational audienceSewage systems may be the preferred pathways for plastic debris from urban areas to the natural environment during wet periods. Some French local authorities are trying to prevent this leakage into the environment by equipping combined sewer (mixed of stormwater and wastewater) or stormwater outfalls (separate sewer systems) with nets. More than a curative solution, these devices represent a unique opportunity to monitoring urban litter, including plastic debris, as close as possible to their source of emission, i.e., urban areas. Since 2020, nets are being (or have been) in used in French cities. In several cities, anthropogenic litter from the nets was collected, washed, air dried and sorted according to the J-list classification (Fleet et al., 2021), which is the updated European classification first developed for marine and riverine litter (MSFD Technical Subgroup on Marine Litter, 2013). Results show that urban waters are a major source of macroplastics for rivers, with mass flows per capita within the orders of magnitude of those estimated in French rivers (1-10 g/cap/yr). In addition, mass flows and items categories differ relative to the type of sewage systems, land use and local specificities. In combined sewer, wipes are by far the main waste found in nets often followed by tobacco-related products and sweet wrappers from roadways. In stormwater run-off, tobacco-related products and sweet wrappers are the main categories by numb, but bottles (in metal, glass and plastic) rank TOP 5 by mass. Acquiring those data is a very harsh task and a dedicated technical platform is under development to extend monitoring at the national level (or beyond) over the long term.
Optimal Vaccination Strategies for an Heterogeneous SIS Model
No full textWe study in a general mathematical framework the optimal allocation of vaccine in an heterogeneous population. We cast the problem of optimal vaccination as a bi-objective minimization problem min(C(η),L(η)), where C and L stand respectively for the cost and the loss incurred when following the vaccination strategy η, where the function η(x) represents the proportion of non-vaccinated among individuals of feature x.To measure the loss, we consider either the effective reproduction number, a classical quantity appearing in many models in epidemiology, or the overall proportion of infected individuals after vaccination in the maximal equilibrium, also called the endemic state. We only make few assumptions on the cost C(η), which cover in particular the uniform cost, that is, the total number of vaccinated people.The analysis of the bi-objective problem is carried in a general framework, and we check that it is well posed for the SIS model and has Pareto optima, which can be interpreted as the “best” vaccination strategies. We provide properties of the corresponding Pareto frontier given by the outcomes (C(η), L(η)) of Pareto optimal strategies
Extreme Event Attribution in the Mediterranean
No full textInternational audienceThe Mediterranean basin is a hot spot of climate change in simulated scenarios, where effects are already observable. Increases in some climate extremes (terrestrial and marine heatwaves, agricultural droughts, extreme precipitation in some areas, and fire weather) are already observed. These extremes are expected to further increase in the future, together with more frequent pluvial and coastal floods, a reduction in cyclone and medicanes frequency (but increase of their maximum intensity) and increasing meteorological droughts. This review paper addresses methodological advances in the science of extreme event attribution, that is, techniques to better understand how much anthropogenic climate change affected the intensity, frequency and physical processes leading to observed extreme weather events, with a focus on studies in the Mediterranean basin. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes
Entretien "Maxime Zaït de Communa nous parle des modèles alternatifs à la propriété. Les tiers-lieux face à la propriété": Blog de l'Observatoire National des tiers-lieux, France Tiers-Lieux.
No full texthttps://observatoire.francetierslieux.fr/maxime-zait-de-communa-nous-parle-des-modeles-alternatifs-a-la-propriete/De l’urbanisme temporaire au pérenne… il n’y a pas qu’un pas ! Pendant 10 ans, l’association belge Communa a ouvert et géré des dizaines de lieux de vie, a animé des communautés d’habitants, d’artisans, a fait vivre ces tiers-lieux. Pendant 10 ans, Communa a également fermé certains de ces lieux et travaille aujourd’hui pour pérenniser et sanctuariser ces espaces communs en ville. Ce chemin, de l’occupation temporaire au pérenne, de nombreux collectifs de tiers-lieux et d’acteurs dits de « l’urbanisme transitoire » l’empruntent désormais en France, mais aussi ailleurs en Europe. Maxime Zaït, cofondateur de Communa et chercheur à la Vrije Universiteit Brussel, revient dans cet entretien sur les évolutions connues par Communa et d’autres collectifs en Europe vis-à-vis des enjeux relatifs à la propriété
Parental Income and Higher Education: Evidence From France
No full textDocuments de travail du Centre d’Économie de la Sorbonne 2025.04 - ISSN : 1955-611XThis paper offers new stylized facts on inequality of enrollment in higher education according to parental income in France. On average, an increment of 10 percentiles in the parental income distribution is associated with a 5.8 percentage-point increase in the proportion of individuals entering higher education. This degree of inequality is strikingly close to that observed in the United States. We identify potential explanatory factors behind this similar degree of inequality in two markedly different institutional contexts. We then explore one consequence of enrollment disparities, assessing the distribution of spending on higher education.Nous mettons en évidence de nouveaux éléments sur les inégalités d'inscription dans l'enseignement supérieur selon le revenu des parents en France. En moyenne, le taux d'accès des jeunes à l'enseignement supérieur augmente de 5,8 points de pourcentage (p.p.) quand le revenu des parents progresse d'un décile. Ce niveau global d'inégalité est étonnamment proche de celui observé aux États-Unis. Nous identifions les facteurs explicatifs potentiels de ce niveau similaire d'inégalité dans les deux pays dont les contextes institutionnels sont très différents. Enfin, nous explorons une conséquence des disparités d'inscription en évaluant la répartition des dépenses publiques consacrées à l'enseignement supérieur
