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Is Resilience Inherited?
No full textWe here use European Social Survey data to disentangle the 'inherited' and 'contextual' components of resilience, following the approaches taken in Alesina and Giuliano (2010) and Luttmer and Singhal (2011). We suggest that the inherited part of resilience reflects culture in the country of birth, while the contextual part captures both institutions and culture in the country where the individual currently resides. We separately identify these two components via a sample of immigrants, for whom the birth and residence countries differ. We find that resilience is both inherited and contextual, with the latter component being the most important. The 'inherited' component of resilience is larger for men and those who do not have citizenship in their residence country. We last present some evidence from second-generation immigrants of the intergenerational transmission of inherited cultural resilience
Nowcasting Economic Activity with Fat tails and Outliers
No full textThis paper extends dynamic factor models by explicitly incorporating outliers, moving beyond conventional data screening practices. The methodological contribution includes introducing fat tails and outliers multiplicatively into innovation volatility, and two distinct approaches for modelling outliers are presented to address large jumps. Empirical findings demonstrate that outlier-augmented models consistently outperform benchmark models in point and density forecasting, with the most significant improvements observed in nowcasting horizons. Incorporating outliers becomes particularly crucial during major crises, enhancing forecasting accuracy by 44% compared to the benchmark. The uniform-mixture approach is found to be more robust than the student-t models, as it targets extreme variations without disrupting the smoothness of the stochastic volatility process
Données brutes d'observation des Conférences citoyennes régionales du Grand débat national (France, 2019)
No full textEighteen Regional Citizens' Conferences (CCR) (13 in metropolitan regions and five in overseas departments and regions (DROM)) and one National Citizens' Conference dedicated to youth were held during the second phase of the Great National Debate (GDN) (either on March 15-16, 2019, or on March 22-23, 2019). A total of 1,404 people participated: 1,216 in the 13 metropolitan CCRs, 68 in the National Youth Conference (selected through a national lottery based on phone numbers), and 120 in the five DROM CCRs (recruited specifically for each of these territories). For mainland France, this was the largest "random selection" conducted to form a mini-public. This report first presents the recruitment process, commonly referred to as the "random selection." It then describes the observation protocol for the Conferences (set up by the Debate Observatory), as well as the process of administering the questionnaires (by the facilitation and research teams). We then compare the socio-demographic characteristics of the participants in the Citizens' Conferences with those of the population in France, which leads us to note that the Conferences were not representative of the population. Specifically, we observe an over-representation of men, people aged 35 to 64, executives/liberal professions, and intermediate professions in the metropolitan Citizens' Conferences. In contrast, certain population groups were under-represented among the participants in the metropolitan Conferences: women, young people aged 18 to 35, and manual workers. This lack of representativeness raises questions about the descriptive legitimacy of the Conferences. Finally, this document presents the (blank) questionnaires used by the facilitation and research teams, as well as the descriptive statistics of the responses given by the citizens to these questionnaires.Dix-huit Conférences citoyennes régionales (CCR) (13 dans les régions métropolitaines et cinq dans les départements et régions d'outre-mer (DROM)) et une Conférence citoyenne nationale dédiée à la jeunesse se sont tenues dans la deuxième phase du Grand débat national (GDN) (soit les 15 et 16 mars 2019, soit les 22 et 23 mars 2019). 1 404 personnes y ont participé : 1 216 dans les 13 CCR métropolitaines, 68 dans la Conférence nationale sur la jeunesse (à partir d'un tirage au sort national dans la base des numéros de téléphones) et 120 dans les cinq CCR des DROM (à partir d'un recrutement spécifique à chacun de ces territoires). Pour la France métropolitaine, il s'agit du plus vaste « tirage au sort » réalisé pour constituer un mini-public. Ce rapport présente en premier lieu le processus de recrutement, globalement désigné par les termes de « tirage au sort ». Puis nous décrivons le protocole d'observation du déroulement des Conférences (mis en place par l'Observatoire des débats), ainsi que le processus de passation des questionnaires (par les équipes d'animation et de recherche). Nous comparons ensuite les caractéristiques socio-démographiques des participantes et participants aux Conférences citoyennes avec celles de la population en France, ce qui nous conduit à souligner que les Conférences n'étaient pas représentatives de la population. En effet, nous observons, dans les Conférences citoyennes métropolitaines, une sur-représentation des hommes, des personnes âgées de 35 à 64 ans, des cadres/professions libérales et des professions intermédiaires. A contrario, certains groupes étaient sous-représentés parmi les participantes et participants aux Conférences métropolitaines : les femmes, les jeunes de 18 à 35 ans et les ouvrières et ouvriers. Cette absence de représentativité vient questionner la légitimité descriptive des Conférences. Finalement, ce document rapporte les questionnaires (vierges) des équipes d’animation et de recherche, ainsi que les statistiques descriptives des réponses des citoyennes et citoyens à ces questionnaires
Performance of algebraic preconditioners for large-scale simulations of single-phase flow in three-dimensional fractured porous media
No full textA three dimensional fractured-porous medium is classically described by a reduced model, called the discrete fracture matrix (DFM), where the rock matrix remains three-dimensional, while the fracture network is of co-dimension one. Solving single-phase flow in such a medium is particularly challenging, especially when a large number of fractures is present. This difficulty primarily arises from the intricate complexity introduced by the fracture network. This work demonstrates that solving flow in such systems is feasible, even for discrete fracture networks as large as 90,000 fractures. The mixed-hybrid finite element method is employed to discretize the flow problem, resulting in a large linear system that must be solved. However, the efficiency of direct linear solvers is severely hindered by the three-dimensional nature of the problem, requiring a substantial amount of RAM. Iterative methods, when preconditioned with algebraic multigrid techniques, offer a better alternative in terms of memory usage. However, their effectiveness declines significantly as the fracture network grows and transmissivity within the network becomes highly heterogeneous, as both lead to poor conditioning of the linear system. Even more critically, we show that achieving an adequately low tolerance for iterative solvers is essential for accurate flow simulations. The choice of tolerance strongly influences the quality of the solution, insufficient precision can prevent local mass conservation in some cases, resulting in non-physical values in fully advective transport simulations
Ensuring the Sustainability of the U.S. Pay-As-You-Go System *
No full textWe propose a heterogeneous agent model to explore the sustainability of the Pay-As-You-Go (PAYG) pension system in the context of an aging population and an evolving educational system. We also evaluate its implications for wealth distribution. We analyze optimal reform strategies including potential adjustments to income tax rates, pension levels, and retirement age. Our results indicate that a 5-year increase in lifespan requires either a 7 percentage point increase in tax rates or an 18 percentage point reduction in the pension replacement ratio. Without an increase in educational attainment, U.S. GDP would stagnate at 2020 levels. Adjusting the system through pension reductions requires greater savings and leads to lower labor supply distortions. Furthermore, adjusting the PAYG system through changes in the retirement age yields the highest GDP increase among the measures considered. In terms of wealth inequalities, these increase with tax hikes and pension reductions, with the most significant rise occurring when adjusting through a higher retirement age. Regarding welfare, the positive impact of increased education is outweighed by the negative effects of lifespan extension. Finally, postponing the retirement age leads to the smallest reduction in retirees' welfare but also reduces the insurance needs of young people
Nature comme science de la culture
No full textInternational audienceThis article is a presentation of the notion of nature from a historical, cultural and epistemological perspective, for the book Atlas des sciences de la culture.The modern representation of nature, which emerged in the West during the Renaissance, refers to the trend that led to positivism and the natural sciences in the sense of Naturwissenschaften, which range from physics to biology, including chemistry, geology and so on. In the 20th century, however, the dependence of the knowledge built up by the various Naturwissenschaften on the social framework in which they were developed began to be studied. These science studies highlighted the imperfections of the modern vision. This was concomitant with neoliberalism and globalisation, and the theory of ecosystem services, which envisages thinking of nature as an economic resource whose value is given by the market. The liberal economy would gradually establish a utility function for living things. However, philosophies of nature were turned upside down by the discovery of the combinatorial properties of genome molecules, a veritable revolution. This article takes a closer look at this break with the past and its consequences, such as the new ancillary role of mathematics. Cet article est une présentation de la notion de nature sous l’angle historique, culturel et épistémologique, destiné à l’ouvrage Atlas des sciences de la culture.La représentation moderne de la nature, apparue à la Renaissance en Occident, désigne le courant qui débouche sur le positivisme et les sciences de la nature au sens de Naturwissenschaften, qui vont de la physique à la biologie en passant par la chimie, la géologie, etc. Au 20ème siècle cependant, commence à être étudiée la dépendance des connaissances construites par les diverses Naturwissenschaften vis-à-vis du cadre social dans lequel elles ont été élaborées. Ces science studies mettent en lumière les imperfections de la vision moderne. Ce fut concomitant avec le néolibéralisme et la globalisation, et la théorie des services éco-systémiques, qui envisage de penser la nature comme une ressource économique dont la valeur est donnée par le marché. L’économie libérale instituerait progressivement une fonction d’utilité du vivant. Cependant les philosophies de la nature furent bouleversées par la découverte de la combinatoire des molécules du génome, une vraie révolution. L’article approfondit cette rupture et ses conséquences comme un nouveau rôle ancillaire des mathématiques. </p
RNA inverse folding can be solved in linear time for structures without isolated stacks or base pairs
No full textExtended version of WABI 2024, under review at Algorithms for Molecular BiologyInternational audienceInverse folding is a classic instance of negative RNA design which consists in finding a sequence that uniquely folds into a target secondary structure with respect to energy minimization. A breakthrough result of Bonnet et al. shows that, even in simple base pairs-based (BP) models, the decision version of a mildly constrained version of inverse folding is NP-hard. In this work, we show that inverse folding can be solved in linear time for a large collection of targets, including every structure that contains no isolated BP and no isolated stack (or, equivalently, when all helices consist of 3 + base pairs). For structures featuring shorter helices, our linear algorithm is no longer guaranteed to produce a solution, but still does so for a large proportion of instances. Our approach introduces a notion of modulo m-separability, generalizing a property pioneered by Hales et al. Separability is a sufficient condition for the existence of a solution to the inverse folding problem. We show that, for any input secondary structure of length n, a modulo m-separated sequence can be produced in time O(n m 2 m ) anytime such a sequence exists. Meanwhile, we show that any structure consisting of 3 + base pairs is either trivially non-designable, or always admits a modulo-2 separated solution. Solution sequences can thus be produced in linear time, and even be uniformly generated within the set of modulo-2 separable sequences.</div
The Cost of Air Pollution for Workers and Firms
No full textThis paper shows that even moderate air pollution levels, such as those in Europe, harm the economy by reducing firm performance. Using monthly firm-level data from France, we estimate the causal impact of fine particulate matter (PM 2.5 ) on sales and worker absenteeism. Leveraging exogenous pollution shocks from local wind direction changes, we find that a 10 percent increase in monthly PM 2.5 exposure reduces firm sales by 0.4 percent on average over the next two months, with sector-specific variation.Simultaneously, sick leave rises by 1 percent. However, this labor supply reduction explains only a small part of the sales decline. Our evidence suggests that air pollution also reduces worker productivity and dampens local demand. Aligning air quality with WHO guidelines would yield economic benefits on par with the costs of regulation or the health benefits from reduced mortality.</p
Calibration of Upper Air Water Vapour Profiles Using the IPRAL Raman Lidar and ERA5 Model Results and Comparison to GRUAN Radiosonde Observations
No full textInternational audienceAccurate measurements of upper troposphere humidity are essential to enhance understanding of contrail formation and guiding mitigation efforts. This study evaluates the ability of the IPRAL Raman Lidar, located south of Paris, to provide high-resolution water vapour mixing ratio (WVMR) profiles at contrail-relevant altitudes. Raman signals are screened on hourly bases, and a universal calibration method, independent of acquisition mode, is proposed towards operational Lidar water vapour profiles, using co-located ERA5 data. Calibration factors are derived from comparisons between 4 and 6 km, and nightly coefficients determined from hourly factors. Instrumental stability is monitored through the temporal evolution of calibration factors, and stable-period medians are adopted as final values. The uncertainty of calibrated WVMR profiles is assessed by comparison with GRUAN processed Meteomodem M10 radiosondes and ERA5 data. Results show a high agreement (>90%), with IPRAL exhibiting a small negative bias (~10%) below 8 km, reducing to ~5% up to 10.5 km to radiosondes. ERA5 systematically underestimates water vapour at cruise altitudes, with a dry bias increasing from 10% at 9 km to >20% at 11 km. Recent IAGOS corrections to ERA5, improving supersaturation representation, are validated over Paris. This calibrated Lidar data set supports improved atmospheric modelling and contributes to future air traffic management strategies
Pour une science de la Transition Énergétique au Service de la Société: Rapport du groupe interdisciplinaire ARPEGES CNRS pour la Transition énergétique
No full textNational audienceResearch on the energy transition raises a series of major challenges: it is a problem-oriented field of research (that of decarbonising the energy mix), which must be resolutely ethical and include principles of social and environmental justice from the very beginning... and this despite the problematic nature of the notion of transition which gives a misleading notion of the process that will lead to desired changes - if there are any. Taking this observation as its starting point, this paper sets out a number of avenues for research into key issues. It begins by examining the way in which the energy transition is transforming the interplay between actors in the energy sector and the scales at which decisions are taken and implemented. While inviting to take account of the wide variety of national contexts and levels of development, the article acknowledges the certainties and uncertainties surrounding the composition of the energy mix. It also stresses the importance of taking account of the externalities of technological choices, particularly in environmental terms. This enables us to draw up a research agenda focusing not only on the spatial aspects of transitions, but also on the ways in which economic models need to incorporate new parameters and new constraints. The article also invites to consider how the relationship between energy production and consumption is changing, and how consumption needs to be reduced. In so doing, the article defends the idea that research, which is necessarily interdisciplinary and reflexive, has a strong role to play in basing transition action on scientifically sound findings.La recherche sur la transition énergétique pose plusieurs défis de taille : c’est une recherche orientée problème (celui de la décarbonation du mix énergétique), qui doit être résolument éthique et intégrer dès sa formulation des principes de justice sociale et environnementale... et ce alors même que la notion de transition est problématique en ceci qu’elle donne une fausse idée du processus qui mènera aux changements attendus – si changements il y a. Partant de ce constat, ce Regard dresse des pistes de recherche sur des thématiques saillantes, notamment sur les acteurs et échelles des transitions, les techniques et leurs externalités, les modèles économiques et sociaux qui permettent de guider l’action, les modèles de consommation production et s’interroge sur les rapports entre consommation et production. Il défend in fine l’idée que la recherche, forcément interdisciplinaire et réflexive, a un rôle fort à jouer pour fonder l’action en matière de transition sur des constats scientifiquement fondés