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[hal-05764643] Discrimination during the Paris 2024 Olympics: Evidence from a field experiment on Airbnb
In a field experiment on Airbnb in Paris during and after the 2024 Olympic Games, we examine how discrimination responds to temporary market disruptions. During the Olympics, booking requests from male and North African–sounding guests were significantly less likely to be accepted than those from female or French-sounding guests. After the Games, discrimination against male guests disappeared, and bias against North African–sounding guests, though still present, declined substantially. Our results suggest that the higher prejudice during the Olympic Games was driven primarily by increased host selectivity in neighborhoods experiencing the strongest Airbnb market tensions. Exploiting variation in Airbnb’s Instant Book feature, we find that ethnic discrimination is primarily statistical, while gender discrimination is more consistent with taste-based preferences for women. Beyond acceptance rates, North African–sounding guests also experienced slower and less enthusiastic positive responses, pointing to both strategic and implicit forms of unequal treatment.
ano.nymous@ccsd.cnrs.fr.invalid (Alexandre Flage) 25 Sep 2026
https://institut-agro-dijon.hal.science/hal-05764643v1
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[hal-05771612] Enhancing public acceptability of Low Emission Zones: The role of accompanying measures
The effectiveness of Low Emission Zones (LEZs) in improving air quality and public health has been widely demonstrated. However, their implementation may encounter acceptability challenges, which can lead public authorities to scale back their ambition or even suspend implementation. Indeed, LEZs raise social justice concerns related to the distribution of health benefits across the population and may exacerbate mobility-related vulnerabilities. Accompanying measures are therefore required to address these challenges and to promote the implementation of effective and equitable LEZs that are better accepted by the public. Nevertheless, tensions may arise between accompanying measures designed to address social equity and the environmental effectiveness of LEZs. Based on a survey conducted prior to the implementation of the LEZ in Grenoble (France), we analyze the relationship between LEZ acceptability and support for accompanying policies, whether aimed at strengthening environmental effectiveness or addressing social justice concerns. Using clustering methodology, we identify six profiles: three groups supportive of the LEZ (Enthusiasts, Not concerned, and Anti-Exemptions) and three groups opposed to it (Detractors, Not Convinced, and Potential Allies). Regarding accompanying policies, these profiles reveal a central policy challenge: improving communication about the potential effectiveness of LEZs, while addressing the social justice concerns of Potential Allies and taking into account the environmental effectiveness concerns expressed by the Anti-Exemptions group. Regardless of the accompanying policies proposed, the Enthusiasts appear committed to the cause of LEZs, whereas the Detractors remain largely resistant to persuasion.
ano.nymous@ccsd.cnrs.fr.invalid (Hélène Bouscasse) 30 Sep 2026
https://hal.inrae.fr/hal-05771612v1
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[hal-05784547] Return on investment for promoting homeownership: the case of the french interest-free loan policy
We evaluate whether subsidies to first-time homebuyers expand homeownership, distort housing choices, or are capitalized into housing prices. For France's interest free loan program between 2015 and 2019, we combine temporal and spatial variation in policy parameters with a doubly robust estimator to jointly assess the different causal effects of the policy. We find limited effects on homeownership, while purchase prices increase strongly with the intensity of the subsidy, indicating substantial price capitalization. Policy simulations show that the marginal return on public spending is low and often negative. These results highlight how policy design and market conditions shape the effectiveness of homeownership subsidies.
ano.nymous@ccsd.cnrs.fr.invalid (Rémi Lei) 07 Oct 2026
https://hal.science/hal-05784547v1
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[hal-05771760] Digressions
Au risque de paraphraser le récit de la 7 e journée sciences ouvertes du Centre National de Recherche Scientifique, cela fait quelques années qu'il y a quelque chose de « vicié » dans le monde des publications scientifiques. La situation semble s'emballer dans la mesure où environ cinq millions d'articles inédits se sont ajoutés en 2025 au volume total des publications scientifiques (contre un million dans les années 1980), sans que cette augmentation soit corrélée à l'augmentation du nombre de scientifiques. Au cours de cette même période, la charge administrative des chercheur•e•s s'est considérablement alourdie, les demandes de rendre compte et d'évaluer les autres également. Cette inflation générale du nombre des publications et des charges non directement liées à la production et à la valorisation de la recherche pèse sur l'activité de relecture par les pairs et donc sur la qualité du processus garant de la qualité de la production scientifique en elle-même. Aux problématiques liées aux exigences de publication en masse, déjà évoquées lors de notre premier numéro Digressions, s'ajoutent désormais les enjeux soulevés par l'usage des Grands Modèles de Langage, aussi connus sous le nom d'Intelligence Artificielle Générative (IA gen). Ces technologies peuvent être utilisées pour accélérer encore le processus de production ou de révision d'un article. Mais combien de chercheur•e•s les utilisent et comment ? Cela reste encore difficile à estimer. Leur usage est fortement variable d'un usager à l'autre : de simples corrections orthographiques, grammaticales ou syntaxiques, jusqu'à la rédaction (voire l'invention) intégrale de l'article, de la production de ses données à leur analyse, voire à sa bibliographie, pour les moins éthiques. Difficile de ne pas voir comment ces outils peuvent corrompre les fruits de la recherche, celle-là même qui dénonce leurs impacts négatifs sur l'apprentissage et l'esprit critique (Stone, 2025), mais aussi sur la consommation et la prédation d'eau, de terre et d'énergie à l'échelle mondiale (Crawford, 2024; Trystram et al., 2025).
ano.nymous@ccsd.cnrs.fr.invalid (Nicolas Baptiste) 01 Oct 2026
https://hal.science/hal-05771760v1
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[hal-05679169] Biodiversity impact of agricultural products in France: Greater differences across product types than food quality schemes
<div><p>Although agriculture contributes to four main drivers of biodiversity loss, the impact assessment of food products remains limited to either in situ measurements that preclude generalization or to systematic models that are not calibrated on in situ data. Here we describe the BVIAS (Biodiversity Value Increment from Agricultural Statistics) model, which estimates the biodiversity impact of food products using accountancy data and public statistics for use in environmental labeling schemes or other purposes. Going beyond existing methods, BVIAS accounts for the main drivers of biodiversity loss related to agriculture, relies on a large farm dataset (&gt;5,000 farms), and is calibrated using in situ data from the literature. We apply it to compare major Food Quality Schemes (FQSs) to their conventional counterparts. We show that only explicit requirements (e.g., ban on pesticides, grass-fed content) in FQS specifications lead to significant differences in practice. Consistent with the literature, we find that organic farms have a lower biodiversity impact on a per-hectare basis, as well as those producing Comté (Protected Designation of Origin), but lower yields offset this local benefit, resulting in a higher impact per ton. However, the biodiversity impact gap between product types (here milk vs. cereals) is far greater than the difference between FQS and conventional versions of the same product. This study highlights that, for environmental labeling, the distinction between product types is more important than the distinction between FQS and conventional.</p></div>
ano.nymous@ccsd.cnrs.fr.invalid (Sarah Huet) 03 Jul 2026
https://hal.inrae.fr/hal-05679169v1
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[hal-05766892] The resurgence of phytotherapy in livestock farming as an alternative to antibiotic therapy: controversial practices
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Lucile Benoit) 28 Sep 2026
https://hal.inrae.fr/hal-05766892v1
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[hal-05786082] Territoires en résistance
Les raffineries et les cimenteries tournent à plein régime, la bataille contre le changement climatique est au point mort et le green backlash atteint des sommets. Difficile d'imaginer que l'écologie puisse l'emporter. Ce portrait global ne dit pas tout. Partout en France, des territoires entrent en résistance. Des luttes locales sont menées afin de barrer la route à des projets écocidaires, et les victoires sont nombreuses depuis les années 1970. En faisant plier un industriel, une collectivité ou même l'État, des collectifs ont réussi à stopper la construction d'autoroutes, d'incinérateurs, de golfs ou encore de mégacentres commerciaux. Autant de projets inutiles et destructeurs qui menacent nos territoires. Ces victoires sont trop souvent méconnues, passées sous silence ou oubliées. Il est temps de raconter cette histoire de luttes victorieuses : pour se remémorer et commémorer la combativité des militant·es, mais surtout pour mieux préparer celles de demain.
ano.nymous@ccsd.cnrs.fr.invalid (Gaëlle Ronsin) 08 Oct 2026
https://hal.science/hal-05786082v1
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[hal-05749947] The dynamic impact of land-use changes on soil organic carbon
This study examines the response of soil organic carbon (SOC) to land-use changes (LUCs) across Europe. Using field data from the LUCAS survey and satellite-based Corine Land Cover data, we find that SOC losses due to conversions to cropland are immediate (63% occurs within the first 1.5 years) whereas SOC accumulation following conversions from cropland to grassland or forest is more gradual (10–20 years) but still with a notable peak in the first 1.5 years. Our dynamic approach reveals a potentially much higher carbon sequestration from LUC (an indicative 572 MtC between 1990 and 2021) than reported by current national inventories (76 MtC), although both approaches come with substantial limitations. These findings suggest that conservative IPCC Tier 1 estimates may understate the mitigation potential of land-use policies. We provide ready-to-use, country-specific emission factors to improve the precision of national greenhouse gas inventories and to support compliance with public regulation, though further validation is needed for forest-related LUCs due to small sample sizes and the possible incorporation of forest litter into topsoil measurements.
ano.nymous@ccsd.cnrs.fr.invalid (Liang Diao) 15 Sep 2026
https://hal.inrae.fr/hal-05749947v1
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[hal-05766917] Bottom-up’ socio-technical transitions: the example of rearing young dairy calves
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Florence Hellec) 28 Sep 2026
https://hal.inrae.fr/hal-05766917v1
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[hal-05720166] How agricultural subsidies shape local employment: evidence from the French support policies for mountain areas
Do place-based farm subsidies reshape rural labour markets beyond agriculture? We estimate the causal impact of France’s mountain-area support (MA) scheme within the Less Favoured Areas (LFA) framework on municipal employment over 1962–1990, combining entropy balancing with an extended two-way fixed-effects estimator on 23,651 municipalities. We find that MA classification reduces total agricultural employment by roughly 15%, driven by an 18% decline in self-employment as farms consolidate and expand. Salaried farm jobs rise by about 16%, but this increase falls well short of offsetting the contraction of family labour. We also document positive spillovers to neighbouring municipalities and inter-sectoral linkages beyond agriculture: trade and services expand within treated municipalities, while agri-food and construction employment rises in nearby untreated areas. Treatment heterogeneity indicates stronger effects where farms are mid-sized and market access is limited, suggesting the programme compensates for labor market thinness in remote areas rather than complementing pre-existing urban advantages. Overall, a policy designed to sustain farming in disadvantaged areas appears to have reconfigured both the composition and the spatial distribution of rural employment.
ano.nymous@ccsd.cnrs.fr.invalid (Yrabo Dabou) 29 Aug 2026
https://hal.science/hal-05720166v2
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[hal-05734153] Housing Wealth Beyond Prices: Individual Portfolios, Distant Assets, and Transfers in France 2011–2022
Using a new dataset covering all French homeowners and all housing properties each year between 2011 and 2022, we provide the first dynamic nationwide analysis of housing wealth. Our results show that the values of main residences explain most housing wealth differences between cities, while the values of additional properties amplify differences within cities. Moreover, distant ownership reduces inequalities generated from housing price variations, and inheritances and gifts strongly contribute to wealth concentration. Overall, the geography of housing wealth differs substantially from the geography of housing prices. It is therefore central to consider entire property portfolios to study housing wealth.
ano.nymous@ccsd.cnrs.fr.invalid (Rémi Lei) 01 Sep 2026
https://institut-agro-dijon.hal.science/hal-05734153v1
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[hal-05784857] Analyse territoriale des freins et leviers au développement de la filière légumineuses à destination de l’alimentation humaine en Bourgogne France Comté et recommandations
Ce rapport, réalisé dans le cadre du projet Pulse Fiction, analyse les freins et leviers au développement de la filière légumineuses destinées à l’alimentation humaine en Bourgogne-Franche-Comté. Il repose sur 22 entretiens semi-directifs menés entre novembre 2025 et février 2026 auprès de producteurs, d’organismes stockeurs, de transformateurs et d’autres acteurs de la filière, analysés selon une approche thématique qualitative. Les résultats mettent en évidence une organisation principalement en micro-filières, dans lesquelles certains acteurs associent production, collecte, stockage et transformation pour accroître la valeur ajoutée. Les freins observés rejoignent ceux identifiés à l’échelle nationale : manque de débouchés, prix peu attractifs, difficultés agronomiques, renouvellement variétal limité, disponibilité des semences et concurrence internationale. Le faible engagement des organismes stockeurs et le manque de structuration collective limitent également le développement de la filière. Les leviers identifiés reposent notamment sur la restauration collective locale et la diversification des activités autour des légumineuses. Les recommandations soulignent l’intérêt d’une animation régionale pour faciliter la mise en relation des acteurs, le partage des connaissances et la structuration des débouchés, ainsi que le développement des capacités de transformation.
ano.nymous@ccsd.cnrs.fr.invalid (Mélanie Favrot) 07 Oct 2026
https://hal.inrae.fr/hal-05784857v1
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[hal-05695264] Who benefits most from fare-free public transport? Evidence of social and neighborhood effects from the case of Clermont-Ferrand, France
This paper estimates the impact on household mobility of the fare-free public transport measure implemented on weekends in Clermont-Ferrand, France. More precisely, we are interested in the influence of socioeconomic determinants on the likelihood of using public transport more often following the introduction of a free travel measure. We investigate changes in travel behavior at the individual level, using data from the household travel survey (Cerema Certified Mobility Survey -EMC²) conducted in the metropolitan area of Clermont-Ferrand in 2023. We built a weighted binary logistic regression to estimate the probability that users increase their public transport use due to the fare-free policy, depending on their socioeconomic characteristics. The results show that free public transport increased usage for more than half of users, with effects varying across individual characteristics. In Clermont-Ferrand, low-income households, residents of priority urban districts, and families with children benefit more from the fare-free policy. We demonstrate that residing in a priority urban district (QPV) has a specific impact. All else being equal, residents living in a QPV have an estimated 85% probability of increasing their use of public transport following the introduction of farefree travel, corresponding to a 31-percentage-point (pp) higher probability than residents living outside a QPV. Therefore, the estimated impacts are not merely compositional but reflect genuine contextual externalities operating at the local level: There exists a neighborhood effect. This study intends to contribute to the literature on free public transport policy evaluation, with a focus on the socioeconomic heterogeneity of effects.
ano.nymous@ccsd.cnrs.fr.invalid (Marion Drut) 16 Jul 2026
https://hal.science/hal-05695264v1
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[hal-05734180] 2025 JGS Best Paper Award and the Editors’ Choice Paper Volume 28(2)
This editorial presents the 2025 Journal of Geographical Systems Best Paper Award and the Editors’ Choice papers in Volume 28(2). It highlights outstanding contributions to geographical systems research, recognizing innovative approaches and significant advances in spatial analysis. The editors emphasize the quality, originality, and scientific relevance of these selected studies.
ano.nymous@ccsd.cnrs.fr.invalid (Manfred Fischer) 01 Sep 2026
https://institut-agro-dijon.hal.science/hal-05734180v1
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[halshs-05713094] Bees and beekeepers facing climate change: reconfiguration of beekeeping work
Beekeeping is an agricultural activity as little known as it seems enchanting. Its close relationship with nature generally feeds the image of a romantic activity, the realities of which often remain hidden. In France, it is mainly practiced by hobbyists: professionals, who have more than 200 hives and make their living solely from beekeeping, represent only 4% of beekeepers. The French beekeeping worlds are facing several crises: health, Asian hornets, economic, land and now climate. The latter may seem like just “another crisis,” but we will show that it is leading to profound and unprecedented changes in beekeeping practices. Among agricultural activities, beekeeping is undoubtedly the one that is most dependent on and sensitive to natural conditions, on which it is heavily reliant. Bees and beekeepers live and work in tune with the seasons, and mainly with flowering periods. Flower nectar and pollen are vital food resources for bees throughout the year. Their presence in bees' environment determines not only the survival, health, and development of the colony, but also the type and quantity of the honey harvest, and consequently the work and income of beekeepers. This presentation aims to analyze how climate change is affecting and transforming technical, temporal, and organizational aspects of beekeeping, revealing its very nature. We will draw on field studies conducted in France since 2022, based on sociological interviews. Whatever the beekeeping system (sedentary or migratory), the work involves movement and travel within a territory: bees are looking for flowers and resources, and humans move from one apiary to another to harvest honey and monitor bees. Climate change manifests itself in two extreme situations: the consequences on beekeeping work will be examined. On the one hand, prolonged periods of drought and, on the other hand, periods of intense and abnormally long rainfall, as it was the case in France in spring 2024. In the first case, the living and working conditions for humans and bees become particularly difficult, and even dangerous, forcing humans to move around repeatedly. In the second case, bees can no longer forage: food shortages threaten them and compromise the harvest, forcing beekeepers to make choices that raise certain ethical issues.
ano.nymous@ccsd.cnrs.fr.invalid (Lucie Dupre) 07 Aug 2026
https://shs.hal.science/halshs-05713094v1
