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Nature, culture and inequality. A comparative and historical perspective
No full textInternational audienceIn this unique work, Thomas Piketty presents a synthesis of his historical and comparative research on inequality. He challenges the idea that there could be natural inequalities and shows that the march toward equality has always depended on political and social struggles, addressing diverse topics such as: education, inheritance, the climate crisis, the taxation of wealth, and gender disparities. Adapted from Piketty’s 2022 lecture at the Musée du Quai Branly – Jacques Chirac, Nature, Culture, and Inequality makes his important argument available to a wider audience for the first time. With a clear, conversational tone, he provides a strong foundation of data and concrete examples of how we can continue to level the playing field
Révision de la taxation des boissons sucrées en France : quelles intentions pour quels effets ?
No full textInternational audienceTaxing sugary drinks is a public health measure that has been enacted in a growing number of jurisdictions over the past 15 years. This intervention needs to be evaluated, and its aims clarified. Based on the results of a multidisciplinary research project, in this article we report on the conditions that led to the revision of the taxation of sugar-sweetened beverages in France in 2018. We found an intention to improve the nutritional quality of the beverage offer rather than directly influence consumer behavior. We discuss some of the effects associated with the tax implementation.La taxation des boissons sucrées est, depuis 15 ans, une mesure de santé publique appliquée sur un nombre croissant de territoires. Cette intervention gagne à être évaluée, ce qui implique d’en clarifier les finalités. Basé sur les résultats d’un projet de recherche pluridisciplinaire, cet article analyse les conditions de la révision de la taxation des boissons sucrées en France en 2018. Il met en évidence que l’intention est plutôt de faire évoluer la qualité nutritionnelle de l’offre de boissons que d’influencer directement le comportement des consommateurs. Par ailleurs, il présente quelques effets associés à la mise en oeuvre de la taxe
A roadmap for the atmospheric characterization of terrestrial exoplanets with JWST
No full textInternational audienceUltra-cool dwarf stars are abundant, long-lived, and uniquely suited to enable the atmospheric study of transiting terrestrial companions with JWST. Amongst them, the most prominent is the M8.5V star TRAPPIST-1 and its seven planets. While JWST Cycle 1 observations have started to yield preliminary insights into the planets, they have also revealed that their atmospheric exploration requires a better understanding of their host star. Here, we propose a roadmap to characterize the TRAPPIST-1 system-and others like it-in an efficient and robust manner with JWST. We notably recommend thatalthough more challenging to schedule-multi-transit windows be prioritized to mitigate fleck[86]
Workers as Partners: a Theory of Responsible Firms in Labor Markets
No full textWe develop a theoretical framework analyzing responsible firms (REFs) that prioritize worker welfare alongside profits in labor markets with search frictions. At the micro level, REFs' use of market power varies with labor conditions: they refrain from using it in slack markets but may exercise it in tight markets without harming workers. Our macro analysis shows these firms offer higher wages, creating a distinct high-wage sector.When firms endogenously choose worker bargaining power, there is a trade-off between worker surplus and employment, though this improves with elastic labor supply. While REFs cannot survive with free entry, they can coexist with profit-maximizing firms under limited competition, where their presence forces ordinary firms to raise wages
Trade and diplomacy Economic determinants of international cooperation agreements and its effect on international trade in the post World War II era: 1945-2022
No full textWe study the determinants of international cooperation and its effect on trade. We rely on a unique database of 31,982 International Cooperation Agreements (ICAs) signed between 1945-2022 by 193 countries. Estimating bilateral gravity equations, we find that trade follows the flag: ICAs increase bilateral exports by around 1-3%, with stronger effects for South-South relations.We address potential endogeneity through panel approach and an instrumental variable that exploits the network structure of international relations. Further, using LPM we find that gravity forces explain country pairs entering an ICA. Importantly, we find that ICAs serve as stepping stones towards Regional Trade Agreements, confirming a previous step in Balassa (1961) theory ofeconomic integration. Our results shed new light on the international relations-trade nexus and contribute to the current debate on friendshoring
Use of FRP rebars in reinforced concrete structures: overview of the French AFGC guidelines
No full textInternational audienceIn 2018, the French Civil Engineering Association (AFGC) established a working group on the use of Fibre-Reinforced Polymer (FRP) bars for internal concrete reinforcement to formulate French recommendations. Published in 2021 and translated into English in 2023, the recommendations cover the characterisation methods of FRP bars, their durability and temperature behaviour and design recommendations
What Are Social Norms?
No full textDocuments de travail du Centre d'Economie de la Sorbonne 2024.09 - ISSN : 1955-611XMany theorists tie social norms to attitudes, such as expectations on others, perhaps along with conforming practices. Challenging this view, we instead ground social norms in a social norming process, an often non-verbal social communication process that ‘makes’ the norm through mutual expressions of support. We present the process-based account of social norms and social normativity, and distinguish social norms from social pressures, social practices, and Lewisian conventions. The process-based view brings social norms closer to legal norms, by tying them to ‘expressive acts’, just as laws and contracts arise through acts of voting or signing, not through mere attitudes
Impact Of Boundary Layer Stability On Urban Park Cooling Effect Intensity
No full textInternational audienceThe added heat in cities amplifies the health risks of heat waves. At night under calm winds and cloud-free skies, the air in the urban canopy layer can be several degrees warmer than in rural areas. This lower nocturnal cooling in the built-up settings poses severe health risks to the urban inhabitants, as indoor spaces cannot be ventilated effectively. With heat waves becoming more frequent and more intense in future climates, many cities are expanding their green spaces with the aim to introduce cooling through shading, evaporation and lower heat storage capacities. In this study, we assessed how the evening and nighttime cooling effect of urban parks (relative to nearby built-up settings) varies with the park size and the mesoscale atmospheric conditions during warm summer periods. Using a combination of meteorological surface station data and compact radiosondes, the cooling effect is quantified for several urban parks (about 15 ha) and urban woods (about 900 ha). A profiling Doppler wind lidar deployed in the city centre is used to measure turbulent vertical mixing conditions in the urban boundary layer. We find that the maximum nocturnal cooling effects in urban parks range around 1–5 °C during a 1-week heat wave event in mid-July 2022 but also in general during summer 2022 (June–August). Three atmospheric stability and mixing regimes are identified that explain the night-to-night variability in the park cooling effect. We find that very low turbulent vertical mixing in the urban boundary layer (<0.05 m2 s‑2) results in the strongest evening cooling in both rural settings and urban parks and the weakest cooling in the built-up environment. This regime specifically occurs during heat waves in connection with large-scale advection of hot air over the region and corresponding subsidence. When nocturnal turbulent vertical mixing above the city is stronger, the evening cooling in urban green spaces is less efficient, so the atmospheric stratification above both urban parks and woods is less stable, and temperature contrasts compared to the built-up environment are less pronounced. These results highlight the fact that urban green spaces have a significant cooling potential during heat waves, with maximum effects at night as advection and mixing transport processes are minimal. This suggests adapting the opening hours of public parks to enable residents to benefit from these cooling islands
Aera-Mip: Emission Pathways, Remaining Budgets, And Carbon Cycle Dynamics Compatible With 1.5 And 2 °C Global Warming Stabilization
No full textInternational audienceWhile international climate policies now focus on limiting global warming to well below 2 °C or pursuing a 1.5 °C level of global warming, the climate modelling community has not provided an experimental design in which all Earth system models (ESMs) converge and stabilize at the same prescribed global warming levels. This gap hampers accurate estimations based on comprehensive ESMs of the carbon emission pathways and budgets needed to meet such agreed warming levels and of the associated climate impacts under temperature stabilization. Here, we apply the Adaptive Emission Reduction Approach (AERA) with ESMs to provide such simulations in which all models converge at 1.5 and 2.0 °C warming levels by adjusting their emissions over time. These emission-driven simulations provide a wide range of emission pathways and resulting atmospheric CO2 projections for a given warming level, uncovering uncertainty ranges that were previously missing in the traditional Coupled Model Intercomparison Project (CMIP) scenarios with prescribed greenhouse gas concentration pathways. Meeting the 1.5 °C warming level requires a 40 % (full model range: 7 % to 76 %) reduction in multi-model mean CO2-forcing-equivalent (CO2-fe) emissions from 2025 to 2030, a 98 % (57 % to 127 %) reduction from 2025 to 2050, and a stabilization at 1.0 (‑1.7 to 2.9) PgC yr‑1 from 2100 onward after the 1.5 °C global warming level is reached. Meeting the 2.0 °C warming level requires a 47 % (8 % to 92 %) reduction in multi-model mean CO2-fe emissions until 2050 and a stabilization at 1.7 (‑1.5 to 2.7) PgC yr‑1 from 2100 onward. The on-average positive emissions under stabilized global temperatures are the result of a decreasing transient climate response to cumulative CO2-fe emissions over time under stabilized global warming. This evolution is consistent with a slightly negative zero emissions commitment – initially assumed to be zero – and leads to an increase in the post-2025 CO2-fe emission budget by a factor of 2.2 (‑0.8 to 6.9) by 2150 for the 1.5 °C warming level and a factor of 1.4 (0.9 to 2.4) for the 2.0 °C warming level compared to its first estimate in 2025. The median CO2-only carbon budget by 2150, relative to 2020, is 800 GtCO2 for the 1.5 °C warming level and 2250 GtCO2 for the 2.0 °C warming level. These median values exceed the median IPCC AR6 estimates by 60 % for the 1.5 °C warming level and 67 % for 2.0 °C. Some of the differences may be explained by the choice of the mitigation scenario for non-CO2 radiative agents. Our simulations highlight shifts in carbon uptake dynamics under stabilized temperature, such as a cessation of the carbon sinks in the North Atlantic and in tropical forests. On the other hand, the Southern Ocean remains a carbon sink centuries after temperatures stabilize. Overall, this new type of warming-level-based emission-driven simulation offers a more coherent assessment across climate models and opens up a wide range of possibilities for studying both the carbon cycle and climate impacts, such as extreme events, under climate stabilization