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The market for "harmful component-free" products under pressure from the NGOs *
No full textNon-governmental organizations (NGOs) are exerting growing pressure on firms to eliminate product components (such as palm oil) that are harmful to the environment (such as rainforests) or replace such components with NGO-certified sustainable components. Under which conditions does NGO pressure lead firms to eliminate basic components from their products or, alternatively, substitute damaging components with certified sustainable components? What are the ensuing effects on market structure, environmental quality, and social welfare? The paper addresses these issues using a model of two-dimensional vertical product differentiation. It shows that, for an NGO that collects certification fees to accrue its budget and finance its awareness campaign, it may — paradoxically — be optimal to reduce the certified product’s market share and eventually evict it
Navigating the 15-minute City: First Learnings and Discussions from the Driving Urban Transitions Partnership
No full textInternational audiencehttps://dutpartnership.eu/news/navigating-the-15-minute-city-first-learnings-and-discussions-from-the-driving-urban-transitions-partnership/Navigating the 15-minute City: First Learnings and Discussions from the Driving Urban Transitions PartnershipThe position paper provides an overview of DUT’s work in the 15-minute City Transition Pathway so far, draws a conclusion and learnings from the first two years of activities, and gives an outlook of what can be expected to come. The authors of this publication aim to sharpen and share their positions on the 15-minute City concept and pave the way towards future policy recommendations in DUT.About the publicationIn a co-creation process, the authors of this publication identified and highlighted the research, municipal, national and european perspectives on the 15-minute City concept, brought in by different stakeholders working in the field of urban mobility.In addition, they present the results of six Critical Issues to operationalise and implement the concept that will require further attention in the upcoming years, such as social justice, the involvement of people and organising the urban mobility transition
Taxing the carbon content of consumed goods
No full textThis note is concerned by the difference between production-based taxation and consumption-based taxation of CO2 emissions. We focus on the possible discrepancy between a carbon tax paid by the producer and a tax on the carbon content of the consumed good. We want to appraise if and how incentives from consumption-based taxation are pushed down the production chain. Depending on whether the producer takes as fixed the price he receives or the price paid by the consumer (price the producer receives plus the tax on carbon content), we have two different conclusions. This raises a puzzle: which price should be considered as fixed? We show that, if producers are rational, they should take the price paid by the consumer as given, not the price received by the producer. In this case, the tax on carbon content (consumption-based taxation) is equivalent to the standard carbon tax (production-based taxation). Our analysis stresses the importance of the producer’s rationality, as well as the importance of differentiating taxation by the actual carbon content, specific to each producer
Parabolic Tamari Lattices in Linear Type B
No full textInternational audienceWe study parabolic aligned elements associated with the type- Coxeter group and the so-called linear Coxeter element. These elements were introduced algebraically in (Mühle and Williams, 2019) for parabolic quotients of finite Coxeter groups and were characterized by a certain forcing condition on inversions. We focus on the type- case and give a combinatorial model for these elements in terms of pattern avoidance. Moreover, we describe an equivalence relation on parabolic quotients of the type- Coxeter group whose equivalence classes are indexed by the aligned elements. We prove that this equivalence relation extends to a congruence relation for the weak order. The resulting quotient lattice is the type- analogue of the parabolic Tamari lattice introduced for type in (Mühle and Williams, 2019)
Changer les comportements et promouvoir le report modal en zone peu dense.
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Bijective proof of a conjecture on unit interval posets
No full textInternational audienceIn a recent preprint, Matherne, Morales and Selover conjectured that two different representations of unit interval posets are related by the famous zeta map in q, t-Catalan combinatorics. This conjecture was proved recently by Gélinas, Segovia and Thomas using induction. In this short note, we provide a bijective proof of the same conjecture with a reformulation of the zeta map using left-aligned colored trees, first proposed in the study of parabolic Tamari lattices
La récupération du coût des services rendus par l’utilisation de l’eau : quel rapport avec l’eau en bien commun ?
No full textInternational audienceIIn Europe, water consumption decline in cities leads operators of water services to raise the unit prices; which in turn leads to question billing as the sole way to cover the costs. The OECD 3 T’s (tariffs, taxes and transfers) cost recovery approach is used to discuss possible solutions to implementing the triple bottom line approach of sustainability in the water services sector; reconciling the three dimensions (economics, environment, equity) which potentially diverge, calls in turn for new governance mechanisms. And when water resources are considered common pool, the recovery of environmental and resource costs paid by authorities in charge of water services could be made by institutions organizing transfers, like payments for environmental services. In France, the agences de l’eau are blocked by central government, and with the implementation of the WFD, the levies system focused on domestic water bills is increasingly used to improve the aquatic environment. This generates a conflict with local authorities and consumer NGOs. The paper proposes a re-organization of the financing system of water policy, rebalancing between tariffs and taxes, and creating levies for common pool resources management at the scale of local ricer basin organizationsEn Europe, en obligeant les opérateurs à relever les prix unitaires, la baisse inédite de la consommation d’eau conduit à une augmentation des factures, dont l’impact social potentiel remet en question le tarif de l’eau comme seul moyen de recouvrer les coûts, en particulier les coûts externes. Même l’OCDE admet que leurs gestionnaires recourent aux trois T (tarifs, taxes et transferts) pour chercher des solutions durables de financement des services publics. Dans l’approche dite des 3 E (économique, environnementale et sociale – ou équitable), le partenariat EAU&3E financé par l’ANR Villes durables a proposé une nouvelle gouvernance pour trouver un compromis entre les trois, et atteindre une durabilité globale. Mais comment récupérer les coûts de l’environnement et des ressources lorsque les ressources en eau sont considérées comme des biens communs ? La solution proposée par les économistes institutionnalistes est la mutualisation entre usagers diversifiés qui s’auto-contraignent à co-financer la politique. Cette forme de gouvernance a besoin d’institutions porteuses des transferts que constituent les paiements pour services environnementaux. En France, les agences de l’eau sont bloquées sur ce point, pour des raisons juridiques qui les distinguent des wateringues néerlandaises et des agences de l’eau de la Ruhr : les comités de bassin comprennent des représentants des usagers, qui selon la constitution ne peuvent percevoir ou dépenser de l’argent public. Les Agences de l’eau n’ont donc pas la maîtrise d’ouvrage, et peuvent seulement financer les porteurs de bons projets environnementaux. De plus, elles tirent l’essentiel de leurs revenus des factures d’eau des usagers domestiques, alors qu’elles doivent également intervenir directement sur l’amélioration du milieu aquatique, au détriment de l’aide aux services publics d’eau et d’assainissement qui les financent. Pourquoi ne pas tenter de jouer sur les établissements publics de bassin, plus locaux que les agences, et qui, eux, disposent de la maîtrise d’ouvrage
Pour une écriture de création en études urbaines
No full textInternational audienceCet article revient sur les fondements théoriques de l’écriture d’un roman de recherche dans le champ des études urbaines. Par cette réflexion sur l’esthétique de la recherche, il s’agissait, pour l’auteure, d’inventer une forme pour déployer des hypothèses et des interprétations des situations observées. Cette expérience s’inscrit dans un double mouvement, centré sur l’enquête, par lequel des pratiques d’écriture d’écrivaines et de chercheuses en sciences sociales se rapprochent, aux franges des sciences, de la poésie et de l’art contemporain. En quoi ce tournant esthétique des sciences sociales est-il le signe d’un épuisement des chercheuses face aux contraintes des écritures (et du travail) académiques dont l’internationalisation et l’intensification conduisent à un formatage au détriment d’une herméneutique de la pensée ? Dans une première partie, l’article reviendra sur l’histoire de la disciplinarisation de l’écriture en sciences sociales. Une seconde partie s’attachera à rappeler le pouvoir heuristique de la fiction. Dans un troisième temps, j’explorerai des pistes formelles d’agencement des formes et de composition des points de vue comme invitation à de nouvelles esthétiques de la recherche
Simulating the West Pacific heatwave of 2021 with analog importance sampling
No full textInternational audienceDuring the summer of 2021, the North American Pacific Northwest was affected by an extreme heatwave that broke previous temperature records by several degrees and lasted almost two months after the initial peak. The event caused severe impacts on human life and ecosystems, and was associated with the superposition of concurrent extreme drivers, whose effects were amplified by climate change. We evaluate whether this record-breaking heatwave could be foreseen prior to its observation, and how climate change affects North American Pacific Northwest worst-case heatwave scenarios. To this purpose, we use a stochastic weather generator with empirical importance sampling. The generator simulates temperature sequences with realistic statistical properties using circulation analogues, chosen with an importance sampling based on the daily maximum temperature over the region that recorded the most extreme impacts. We show how some of the large-scale drivers of the event can be obtained form the circulation analogues, even if such information is not directly given to the stochastic weather generator
Credible Numbers: A Procedure for Reporting Statistical Precision in Parameter Estimates
No full textEconometric software packages typically report a fixed number of decimal digits for coefficient estimates and their associated standard errors. This practice misses the opportunity to use rounding rules that convey statistical precision. Using insights from the testing statistical hypotheses of equivalence literature, we propose a methodology that only reports decimal digits in a parameter estimate that reject a hypothesis of statistical equivalence. Applying this methodology to all articles published in the American Economic Review between 2000 and 2022, we find that over 60% of the printed digits in coefficient estimates do not convey statistically meaningful information according to our definition of a significant digit. If one additional digit beyond the last significant digit is reported for each coefficient estimate, then approximately one-third of the printed digits in our sample would not be reported