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Economics and Literature: A Novel Approach
No full textInternational audienceEconomics and fiction often pursue parallel objectives. Economists analyze human decisions and interactions in markets and other institutions. Fiction writers also provide keen insights into individual minds and motives, examining how their characters respond to conflict and tensions in varied situations. This book explores the insights to be gained from developing this parallel.In each chapter, economists discuss classic or contemporary literary creations, exploring economic incentives that motivate the characters, the economic mechanisms that tie them together, and/or the economic context in which they live and develop. Exploring the synergy across economics and literature offers new understandings of themes, including capitalism and colonialism, marriage and markets, gender norms, inheritance and estates, and the political economy of poverty. The broad and deep range of literary works includes writers from Shakespeare and Goethe, through Chekov and Steinbeck, to recent Nobelists Abdulrazak Gurnah and Han Kang. By offering new understandings of both economics and literature, readers will gain deeper insights into people’s thought processes, choices, and consequences.This book will captivate readers in economics, social sciences, and the humanities and open their minds to the viewing of economic ideas and concepts through the prism of great works of literature
Minimum pricing or volumetric taxation? Quantity, quality and competition effects of price regulations in alcohol markets
No full textReforming alcohol price regulations in wine-producing countries is challenging, as current price regulations reflect the alignment of cultural preferences with economic interests rather than public health concerns. We evaluate and compare the impact of counterfactual alcohol pricing policies on consumer behaviors, firms, and markets in France. We develop a micro-founded partial equilibrium model that accounts for consumer preferences over purchase volumes across alcohol categories and over product quality within categories, and for firms' strategic price-setting. After calibration on household scanner data, we compare the impacts of replacing current taxes by ethanol-based volumetric taxes with a minimum unit price (MUP) policy of C0.50 per standard drink. The results show that the MUP in addition to the current tax outperforms a tax reform in reducing ethanol purchases (-15% vs. -10% for progressive taxation), especially among heavy drinking households (-17%). The MUP increases the profits of small and medium wine firms (+39%) while decreasing the profits of large manufacturers and retailers (-39%) and maintaining tax revenues stable. The results support the MUP as a targeted strategy to reduce harmful consumption while benefiting small and medium wine producers. This study provides ex-ante evidence that is crucial for alcohol pricing policies in wine-producing countries
Une formalisation en Rocq des éléments finis de Lagrange simpliciaux
No full textThe finite element method is a popular method to numerically solve partial differential equations. In the long-term goal of proving its correctness, we focus here on the formal definition of what is a finite element: a record in the Rocq proof assistant with both values and proofs of validity, including the main one called unisolvence. We then instantiate this record with the most popular and useful, the simplicial Lagrange finite elements for evenly distributed nodes, for any dimension and any polynomial degree. These proofs require many results (definitions, lemmas, canonical structures) about finite families, affine spaces, multidimensional polynomials, in the context of finite or infinite-dimensional spaces.La méthode des éléments finis est un outil populaire pour la résolution numérique d'équations aux dérivées partielles. En vue de l'objectif à long terme de la preuve de sa correction, nous nous focalisons ici sur la définition formelle de ce qu'est un élément fini : un enregistrement dans l'assistant de preuve Rocq avec à la fois des valeurs et des preuves de validité, dont la principale appelée unisolvance. Puis nous instancions cet enregistrement avec les plus populaires et utiles, les éléments finis simpliciaux de Lagrange pour des nœuds uniformément répartis, pour toutes les dimensions et tous les degrés de polynômes. Ces preuves exigent de nombreux résultats (définitions, lemmes, structures canoniques) sur les familles finies, les espaces affines, les polynômes multivariés, dans le cadre d'espaces de dimension finie ou infinie
Detecting Looted Archaeological Sites from Satellite Image Time Series
No full textInternational audienceArchaeological sites are the physical remains of past human activity and one of the main sources of information about past societies and cultures. However, they are also the target of malevolent human actions, especially in countries having experienced inner turmoil and conflicts. Because monitoring these sites from space is a key step towards their preservation, we introduce the DAFA Looted Sites dataset, \datasetname, a labeled multi-temporal remote sensing dataset containing 55,480 images acquired monthly over 8 years across 675 Afghan archaeological sites, including 135 sites looted during the acquisition period. \datasetname~is particularly challenging because of the limited number of training samples, the class imbalance, the weak binary annotations only available at the level of the time series, and the subtlety of relevant changes coupled with important irrelevant ones over a long time period. It is also an interesting playground to assess the performance of satellite image time series (SITS) classification methods on a real and important use case. We evaluate a large set of baselines, outline the substantial benefits of using foundation models and show the additional boost that can be provided by using complete time series instead of using a single image
Can parameterizations reproduce the gravity waves momentum fluxes and drag simulated by a global high-resolution model?
No full textInternational audienceWe compare the gravity wave (GW) parameterizations used in the IPSLCM6 climate model with the GWs resolved in the ICON global model with 5 km horizontal resolution. The parameterizations are run offline using ICON fields coarse-grained to a 100 km grid and compared to the GWs with smaller scales that are resolved in ICON. Overall, the drags are comparable, the momentum fluxes align well, and each GW parameterization (fronts, convection, and mountains) plays a role at geographical locations consistent with ICON. Among the differences, we find that in ICON, GWs are substantially attenuated aloft the subtropical jets; this is underestimated by the parameterizations. It could be corrected by tuning the characteristic phase speeds or the breaking criteria in the parameterizations. It also seems that ICON underestimates frontal waves in the mid-latitudes, that the parameterizations underestimate the convective waves in the tropics, and that the mountain waves are more alike
Raman lidar water vapor observations to assess the uncertainty of MLS and ERA5 at the upper troposhere
No full textInternational audienceWater vapor information in the upper troposphere (UT) is crucial for understanding the thermodynamic conditions leading to the formation of cirrus clouds and persistent contrails. Both phenomena significantly contribute to aviation-induced radiative forcing, driving global mitigation efforts. Raman lidars provide high-resolution humidity profiles, describing altitudes prone to ice supersaturation—conditions that are challenging to detect and accurately represent in current models.In this study, Raman lidar Water Vapor Mixing Ratio (WVMR) measurements from various sites in France were used to evaluate the performance of the ERA5 model in assessing humidity at typical aircraft altitudes. Additionally, the uncertainties in Microwave Limb Sounder (MLS) WVMR measurements at the same altitudes were assessed. Raman lidar profiles were aggregated into pseudo-monthly datasets to facilitate comparison with the limited number of MLS overpasses at each site, enabling validation of spatio-temporal pseudo-monthly lidar-matched MLS and ERA5 WVMR profiles.The MLS dataset offers one of the longest records of WVMR, making it a valuable resource for trend assessment. This investigation enables the validated use of these datasets for studying UT humidity trends and variability on seasonal and annual scales over the past decade
Machine learning for modelling unstructured grid data in computational physics: a review
No full textUnstructured grid data are essential for modelling complex geometries and dynamics in computational physics. Yet, their inherent irregularity presents significant challenges for conventional machine learning (ML) techniques. This paper provides a comprehensive review of advanced ML methodologies designed to handle unstructured grid data in high-dimensional dynamical systems. Key approaches discussed include graph neural networks, transformer models with spatial attention mechanisms, interpolation-integrated ML methods, and meshless techniques such as physics-informed neural networks. These methodologies have proven effective across diverse fields, including fluid dynamics and environmental simulations. This review is intended as a guidebook for computational scientists seeking to apply ML approaches to unstructured</div
Les trajectoires de transformation des systèmes agri-alimentaires pour une neutralité carbone
No full textInternational audienceThe national strategy to achieve carbon neutrality by 2050 is aimed at all sectors of activity, includingagriculture and agri-food systems. This article is the result of a round table discussion with four panellists(ADEME, Chambre d'Agriculture, Coopération agricole, economic research), who gave their vision of thescale of the transitions to be made, the difficulties and the resources that should be mobilised. The debatehighlighted the need to rely on technological innovations, as well as organisational and societalinnovations. Coherent public policies encouraging changes in practices that are compatible with theeconomic vitality of the agricultural sector are expected. This decarbonisation trajectory requires theinvolvement of all players, including citizen-consumers, who are being encouraged to change their fooddiet for environmental and health reasons. This is a systemic issue, with regional implications. In additionto energy and food security, it must also consider the ‘one health’ concept as a key lever for an integratedapproach to the food system and its sustainability, also enabling an improved capacity to anticipate crises.Decarbonisation trends in the agricultural sector are still limited, but they do exist. Communicatingpositively about this trajectory of change as a source of opportunities is a key message to better rely on.La stratégie nationale pour atteindre la neutralité carbone en 2050 s'adresse à tous les secteurs d'activités, dont celui de l'agriculture et des systèmes agri-alimentaires. Cet article est le fruit d'une table ronde avec quatre intervenants (ADEME, Chambre d'Agriculture, Coopération agricole, recherche en économie) qui ont chacun apporté leur vision de l'ampleur des transitions à opérer, des difficultés identifiées et des moyens à mobiliser. Le débat a mis en avant la nécessité de s'appuyer sur des innovations technologiques mais également organisationnelles et sociétales, avec le besoin d'une mise en cohérence de politiques publiques incitatives qui permettent des changements de pratiques compatibles avec la vitalité économique du secteur agricole. Cette trajectoire de décarbonation requiert l'implication de tous les acteurs, y compris des citoyens-consommateurs amenés à faire évoluer leurs régimes alimentaires pour des raisons environnementales et sanitaires. La question est d'ordre systémique avec des déclinaisons territoriales et, au-delà de la sécurité énergétique et alimentaire, elle doit aussi considérer le concept « une seule santé » comme un levier clé pour une approche intégrée du système alimentaire et de sa durabilité, en capacité d'anticiper des crises. Les inflexions de décarbonation dans le secteur agricole sont encore limitées mais existent. Communiquer positivement sur cette trajectoire de changement comme source d'opportunités est identifié comme un message d'importance sur lequel davantage s'appuyer
Debt, Power, and Time: The Case of a Brazilian Debt Fair
No full textInternational audienceFar from being linear and regular, the time of debt is characterized by the alternating sequences and contrasting rhythms of repayment. This is examined in this article, which analyses the concept of “government through debt” (Lazzarato, 2012) based on an ethnography of the debt fairs organized in many Brazilian cities. These events bring together debt collectors from banks, credit institutions, large service companies (electricity, telephone, water, etc.), and their debtor customers. The article analyses the debt negotiations that take place in the booth of a major consumer credit institution during one of these events. It shows that, although their debts are not cancelled by their creditors, debtors manage to obtain a temporary respite and further time to pay.Longe de ser linear e regular, o tempo da dívida é caracterizado por sequências alternadas e ritmos de pagamento contrastantes. Este artigo analisa o conceito de “governo por dívida” (Lazzarato, 2012) com base em uma etnografia do feirão de dívidas organizadas em várias cidades do território nacional. Esses eventos reúnem agentes de cobrança dos bancos, das financeiras e grandes empresas de serviços (eletricidade, telefone, água, etc.) e seus clientes devedores. A etnografia foca nas negociações de dívidas que ocorrem no estande de uma financeira durante o feirão de Vitória (Espírito Santo). Ele mostra que, embora os devedores não consigam cancelar suas dívidas, eles conseguem obter de seus credores um suspiro e um prazo maior para pagar