Portail HAL EHESS (École des hautes études en sciences sociales)
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Demand-side strategies enable rapid and deep cuts in buildings and transport emissions to 2050
No full textInternational audienceDecarbonization of energy-using sectors is essential for tackling climate change. We use an ensemble of global integrated assessment models to assess CO2 emissions reduction potentials in buildings and transport, accounting for system interactions. We focus on three intervention strategies with distinct emphases: reducing or changing activity, improving technological efficiency and electrifying energy end use. We find that these strategies can reduce emissions by 51–85% in buildings and 37–91% in transport by 2050 relative to a current policies scenario (ranges indicate model variability). Electrification has the largest potential for direct emissions reductions in both sectors. Interactions between the policies and measures that comprise the three strategies have a modest overall effect on mitigation potentials. However, combining different strategies is strongly beneficial from an energy system perspective as lower electricity demand reduces the need for costly supply-side investments and infrastructure
Bone refits from the Cuzoul de Gramat Mesolithic layers (archaeological site, France)
No full textInternational audienceThe Cuzoul de Gramat is a Prehistoric site located in Gramat, France. Excavation determined Mesolithic and Early Neolithic occupations. This dataset concerns the physical refits determined in the Mesolithic faunal material from two sectors of the site, the South section and the Cave. This record includes: cuzoul-south-fragments.csv: a (9 x 239) table, each line describes a bone object from the South section. cuzoul-south-connection.csv: a (2 x 135) table, each line contains the unique identifiers of two refitting bone pieces from the South section. cuzoul-cave-fragments.csv: a (9 x 239) table, each line describes a bone object from the Cave sector. cuzoul-cave-connection.csv: a (2 x 66) table, each line contains the unique identifiers of two refitting bone pieces from the Cave sector. Rscript-cuzoul-fragments.R: an R script to generate additional variables in the -fragments.csv tables. The -fragments.csv tables includes the following variables: id: fragment unique identifier layer: stratigraphic layer sub.layer: stratigraphic sub-layer square: grid square where the bone piece was found zmin: minimal depth of the location where the bone fragment was found (in metre) zmax: maximal depth of the location where the bone fragment was found (in metre) thickness: thickness of the fragment (in centimetre) length: length of the fragment (in centimetre) and the following variables which are derived from the latest (using the Rscript-cuzoul-fragments.R script): surface: approximated surface of the fragment, product of the thickness by the length (in square centimeter) x: x coordinate of the grid square where the bone fragment was found (in centimetre) y: y coordinate of the grid square where the bone fragment was found (in centimetre) z: approximated z coordinate of the location where the bone fragment was found (in centimetre
Du loisir à la professionnalisation : l’évolution du travail numérique des grimpeurs et grimpeuses de haut niveau sur Instagram
No full textInternational audienceFondé sur une enquête qualitative combinant observations ethnographiques, entretiens semi-directifs et analyse de comptes Instagram, cet article examine les dynamiques sociales et institutionnelles qui façonnent l’appropriation d’Instagram par les grimpeur·ses de haut niveau. Loin d’être homogènes, leurs usages du numérique évoluent en fonction de l’âge et des étapes de la carrière sportive. Alors que les plus jeunes privilégient des pratiques récréatives et ludiques, les athlètes plus âgé·es et plus avancé·es dans la carrière adoptent une approche qui participe au processus de professionnalisation. Leur montée en compétences numériques repose alors sur des apprentissages informels et des ajustements progressifs dans un contexte de tensions entre logiques marchandes et valeurs du sport de haut niveau
Do risk preferences really matter? the case of pesticide use in agriculture
No full textNational audienceEven if there exists an extensive literature on the modeling of farmers’ behavior under risk, actual measurements of the quantitative impact of risk aversion on input use are rare. In this article, we use simulations to quantify the impact of risk aversion on the optimal quantity of input and farmers’ welfare when production risk depends on how much of the input is used. The assumptions made on the technology and form of farmers’ risk preferences were chosen such that they are fairly representative of crop farming conditions in the USA and Western Europe. In our benchmark scenario featuring a traditional expected utility model, we find that less than 4% of the optimal pesticide expenditure is driven by risk aversion and that risk induces a decrease in welfare that varies from −1.5 to −3.0% for individuals with moderate to normal risk aversion. We find a stronger impact of risk aversion on quantities of input used when farmers’ risk preferences are modeled under the cumulative prospect theory framework. When the reference point is set at the median or maximum profit, and for some levels of the parameters that describe behavior toward losses, the quantity of input used that is driven by risk preferences represents up to 19% of the pesticide expenditure
Entre Saône et Mont-Blanc : une histoire politique et sociale de la noblesse savoyarde (mi XIIIe-mi XVe siècles). Présentation de la thèse de doctorat
No full textInternational audienc
Negative results in science: blessing or (winner’s) curse
No full textNational audienceTwo players receiving independent signals on a risky project with common value compete to be the rst to innovate. We characterize the equilibrium of this preemption game as the publicity of signals varies. Private signals create a winner's curse:investing rst implies that the rival has abstained from investing, possibly because he has privately received adverse information about the project. Since players want to gather more evidence in support of the project as a compensation, they invest later when signals are more likely to be private. Because of preemption, the NPV of investment is zero at equilibrium regardless of the publicity of signals. However, for a conservative planner who cares about avoiding unprotable investments, this implies that investment arises too early at equilibrium, and such a planner then prefers signals to be private. This provides a rationale against the mandatory disclosure of negative results in science, notably when competition is severe. Our results suggest that policy interventions should primarily tackle winner-takes-all competition, and regulatetransparency only once competition is suciently mild
Shared mechanisms in pragmatic enrichment with contextual and lexical alternatives
No full textInternational audienceWe explore the role of contextual versus lexical alternatives in pragmatic strengthening using a novel training-with-feedback paradigm. In two experiments, we investigate whether training with inferences over contextual alternatives affects pragmatic strengthening with lexical alternatives, and the other way around. In both Experiments, we find that training that encouraged (or discouraged) pragmatic strengthening of simple disjunctions carried over to complex disjunctions of an unfamiliar kind to our experimental participants. This shows that our novel methodology is effective in training general mechanisms for activating alternatives.In Experiment 2, we showed that this methodology can be made to work across different kinds of alternatives, if certain salience conditions are met
Optimal insurance for time-inconsistent agents
No full textWP TSE n°1256National audienceliquidity shocks for time-inconsistent agents who can privately store resources.When lack of self-control is strong enough, optimal contracts are similar to individual nancial accounts with remunerated savings and costly borrowing. The corresponding rate of return decreases with savings, which gives a theoretical rationale for pension accounts with decreasing incentive schemes, as implemented in most developed countries.Extending the model to an innite horizon, we show that, in the presence of repeated shocks, optimal contracts lead to impoverishment almost surely. Usury laws, capping interest rates, worsen this tendency To over-indebtedness for consumers with low risk aversion. By contrast, hidden storage constrains resource allocation for time-consistent agents, so that optimal contracts induce them to accumulate wealth. Those results show how lack of self-control changes the nature of optimal savings and borrowing instruments, with normative implications in terms of tax policy and credit regulation