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A framework for integrating indoor air quality into the life cycle assessment of buildings: application to the sizing of ventilation rates
No full textAbstract Purpose Life cycle assessment (LCA) methods are used in building ecodesign, but do not currently consider indoor air quality (IAQ). Since we spend about 85% of our time indoors, and are exposed to potentially hazardous substances, IAQ is of particular importance to human health. Its consideration in LCA could help make adequate design choices (e.g. materials, window layouts or ventilation rates) and reduce the building’s impacts, while avoiding their transfer to other life cycle stages. Methods To address this gap, we propose a methodology combining building LCA and models that encompass the whole pollutant pathway, from emission to quantified impacts on human health using the disability-adjusted life years (DALYs) indicator. We account for volatile organic compounds (VOCs) and fine particulate matter (PM 2.5 ), emitted from materials and indoor activities. An optimal ventilation rate allowing to reduce overall IAQ and LCA impacts (namely from energy for space heating and ventilation fans) is identified. The framework’s applicability is demonstrated on a case study: different rooms having distinct uses, occupancy and activity patterns, lead to different emission rates, impacts and optimal ventilation rates. The influence of heat sources (gas, electricity, wood) on optimal rates is assessed and different window layouts for natural ventilation are tested. Results and discussion PM 2.5 and heating are the main sources of impacts, respectively ranging from 40–94%, and 1–31% of total impacts of each room, which range from 2500 µDALY/year to 14200 µDALY/year. Rooms with higher indoor emissions have higher optimal ventilation rates: 1.2 ACH (air changes per hour), 2.9 ACH and 13.2 ACH in the meeting room, office and kitchen respectively. These rates also vary for different heat sources due to their different IAQ and LCA impacts: 2.7 ACH, 5 ACH and 15 ACH for coal (still a common fuel in rural Asian countries), gas and electric fan heating respectively in the living room. The combined use of double-flow ventilation to lower heating needs and filters that reduce PM 2.5 concentrations leads to a 56% decrease in total impacts of the meeting room. Conclusions This study shows the applicability of the framework to building ecodesign. For instance, distinct optimal ventilation strategies can be devised, depending on the room or building use. The framework can also have a regulatory application in public health, through representative archetypes, by providing general recommendations in the tertiary and residential sectors
Production Function Estimation with Multi-Destination Firms
No full textWe develop a procedure to estimate production functions, elasticities of demand, and productivity when firms endogenously select into multiple destination markets where they compete imperfectly, and when researchers observe output denominated only in value. We show that ignoring the multi-destination dimension (i.e., exporting) yields biased and inconsistent inference. Our estimator extends the two-stage procedure of Gandhi et al. (2020) to this setting, which allows for cross-market complementarities. In Monte Carlo simulations, we show that our estimator is consistent and performs well in finite samples. Using French manufacturing data, we find aver- age total returns to scale greater than 1, average returns to variable inputs less than 1, price elasticities of demand between -21.5 and -3.4, and learning-by-exporting effects between 0 and 4% per year. Alternative estimation procedures yield unrealistic estimates of returns to scale, demand elasticities, or both
Blood and gender bias in informal care within the family
No full textInternational audienceThis paper deals with the question of the relative contribution of spouses to the long-term care (LTC) needs of their dependent parents and parents in-law. Starting from a theoretical model and using SHARE data, the paper focuses on the role of gender and blood relationships as well as the effect of differential opportunity costs within the couple. The results tend to confirm the existence of gender and blood biases in the level of informal care provided by each spouse, while their wage does not seem to play a large role. When we consider the relative level of informal care by spouses, the gender and blood biases are confirmed. Furthermore, the wage ratio is negatively related to the informal care ratio. These results imply that informal care and private insurance coverage may depend on the gender composition of children, which may justify differentiated public LTC transfers
Equilibrium and Nonequilibrium Methods for Free-Energy Calculations With Molecular Dynamics
No full textInternational audienceThe past decades have witnessed significant progress in the field of molecular simulation, particularly in enhancing the sampling of complex biological processes. These advancements have allowed a large theoretical and computational community to address a wide range of questions, such as conformational transitions in biomolecular systems and protein-ligand reversible association, which are notoriously impossible to investigate using common brute-force computer simulations. The primary reason for this progress is the development of a diverse set of methods aimed at exploring rare events through reliable free-energy calculations. These methods have provided new ways to enhance the sampling of intricate molecular processes by overcoming the limitations of traditional simulation approaches. However, the introduction of new and often conceptually related methods has made it increasingly challenging to select the best-suited option for a given problem. In this context, it is crucial to understand the theoretical foundations of these approaches and how they can be blended together to improve performance. Here, tracing the mathematical roots of different methods, as well as the connections between them, we show how free-energy calculations have become more robust and efficient for the investigation of complex biological objects, eminently relevant to drug discovery
Adaptive regularization, discretization, and linearization for nonsmooth problems based on primal-dual gap estimators
No full textInternational audienceWe consider nonsmooth partial differential equations associated to a minimization of an energy functional. We adaptively regularize the nonsmooth nonlinearity so as to be able to apply the usual Newton linearization, which is not always possible otherwise. We apply the finite element method as a discretization. We focus on the choice of the regularization parameter and adjust it on the basis of an a posteriori error estimate for the difference of energies of the exact and approximate solutions. Importantly, our estimates distinguish the different error components, namely those of regularization, linearization, and discretization. This leads to an algorithm that steers the overall procedure by adaptive stopping criteria with parameters for the regularization, linearization, and discretization levels. We prove guaranteed upper bounds for the energy difference and discuss the robustness of the estimates with respect to the magnitude of the nonlinearity when the stopping criteria are satisfied. Numerical results illustrate the theoretical developments
Populism and the skill content of globalisation
No full textThe rise of populism worldwide is largely seen as a backlash against globalisation. This column contends that, when examining the determinants of populism, the two dimensions of globalisation – trade and migration – need to be jointly accounted for, as well as their skill content. Low-skill and high-skill globalisation have opposite effects on populism: imports of high-skill goods negatively affect support for right-wing populism, while low-skill immigration results in more right-wing populism and less left-wing populism. Any policy recommendations for protectionism or immigration must consider their skill content and carefully weigh their diverse impacts
Frontiers in attributing climate extremes and associated impacts
No full textInternational audienceThe field of extreme event attribution (EEA) has rapidly developed over the last two decades. Various methods have been developed and implemented, physical modelling capabilities have generally improved, the field of impact attribution has emerged, and assessments serve as a popular communication tool for conveying how climate change is influencing weather and climate events in the lived experience. However, a number of non-trivial challenges still remain that must be addressed by the community to secure further advancement of the field whilst ensuring scientific rigour and the appropriate use of attribution findings by stakeholders and associated applications. As part of a concept series commissioned by the World Climate Research Programme, this article discusses contemporary developments and challenges over six key domains relevant to EEA, and provides recommendations of where focus in the EEA field should be concentrated over the coming decade. These six domains are: (1) observations in the context of EEA; (2) extreme event definitions; (3) statistical methods; (4) physical modelling methods; (5) impact attribution; and (6) communication. Broadly, recommendations call for increased EEA assessments and capacity building, particularly for more vulnerable regions; contemporary guidelines for assessing the suitability of physical climate models; establishing best-practice methodologies for EEA on compound and record-shattering extremes; co-ordinated interdisciplinary engagement to develop scaffolding for impact attribution assessments and their suitability for use in broader applications; and increased and ongoing investment in EEA communication. To address these recommendations requires significant developments in multiple fields that either underpin (e.g., observations and monitoring; climate modelling) or are closely related to (e.g., compound and record-shattering events; climate impacts) EEA, as well as working consistently with experts outside of attribution and climate science more generally. However, if approached with investment, dedication, and coordination, tackling these challenges over the next decade will ensure robust EEA analysis, with tangible benefits to the broader global community
Drying-induced damages in exposed fresh cement-based materials at very early ages: From standard casting to 3D printing
No full textInternational audienceIn this paper, we are studying the shrinkage and microstructural damages induced by drying in samples exposed to drying at very early ages. We measure for two model mortars the average and local shrinkage through microtomography images subtraction along with microstructure evolution through microtomography radiographs. Our measurements showcase the role played by the kinetics of propagation of drying-induced capillary stresses on shrinkage distribution. They moreover show the existence of two distinct types of microstructural damages in such exposed samples occurring at the onset of the sample desaturation after a period as short as a couple of hours. Our analysis allows for a first-order understanding of the scaling of the main stress, length and time scales of the problem with some material parameters such as compressibility and permeability. We finally extrapolate and discuss the consequences of the above features on standard concrete casting and on concrete 3D printing
Des loyautés infidèles: L'engagement politique municipal au prisme de ses dissonances ordinaires
No full textThe memoir opens with a riddle posed by the recent municipal elections: the countless declarations by mayors that they would not stand for re-election, followed by a remarkable rate of re-election. The enigma could be solved by attributing a strategic or moral meaning to the mayors; it could also be seen as the possibility of being loyal without being faithful, of remaining a practising mayor while having lost one's faith. The latter interpretation opens the door to a reflection on the ordinary misalignments of commitment, forms of loyalty that are nevertheless more intermittent and ambivalent, from which it is difficult simply to infer adherence or satisfaction. Often conceptualised in terms of abnormality and psychology (following the example of cognitive dissonance), these misalignments are apprehended in the dissertation as a banal and ordinary component of the mayors' political commitment. They are also reinscribed in social spaces and trajectories that give them variable meanings. In the course of the discussion, various ways emerge of rationalising and legitimising the differences inherent in political commitment, in other words, of accepting them without necessarily seeking to reduce them.Le mémoire s’ouvre sur une énigme posée par les dernières élections municipales : les déclarations innombrables de maires annonçant ne pas se représenter, suivies d’un taux de réélection remarquable. On peut résoudre l’énigme en imputant aux maires un sens stratégique ou moral ; on peut aussi y voir la possibilité d’être loyal sans être fidèle, de rester pratiquant tout en ayant perdu la foi. Cette interprétation ouvre une réflexion sur les désajustements ordinaires de l’engagement, des formes de loyauté malgré tout, plus intermittentes et plus ambivalentes, dont il est difficile d’inférer simplement l’adhésion ou la satisfaction. Conceptualisés souvent dans les termes de l’anormalité et de la psychologie (à l’instar de la dissonance cognitive), ces désajustements sont appréhendés dans le mémoire comme une composante banale et ordinaire de l’engagement politique des maires. Ils sont aussi réinscrits dans des espaces sociaux et des trajectoires qui leurs donnent des significations variables. Se dégagent ainsi, au fil des réflexions, diverses manières de rationaliser et légitimer les écarts inhérents à l’engagement politique, c'est-à-dire de les accepter sans forcément chercher à les réduire
Essais sur l'inégalité et la politique fiscale
No full textThis dissertation comprises five chapters on inequality and fiscal policy.Chapter 1 builds and analyzes a new global database of effective tax rates on capital and labor, and establishes a new stylized fact: while effective capital tax rates have fallen since 1965 in developed countries, in developing countries they have recently risen. In many countries, globalization appears to have supported governments’ability to tax capital.In Chapter 2, data on public expenditures complement the Chapter 1 data on tax revenues, and we estimate the incidence of both along comprehensive pretax national income distributions, worldwide since 1980. We find that redistribution rises with development, but this is entirely due to transfers; tax progressivity is uncorrelated with per capita income. Redistribution has increased in most world regions, except in Africa and Eastern Europe, where it has stagnated.Shifting gears from worldwide estimates to single-country studies, Chapter 3 examines the midcentury decline in inequality in the United States of America. New attention to archival data reveals that the decline in inequality favored the middle class more than the working poor—with one exception: Midcentury wage compression lasted for the entire postwar era. I explain one generation-defining trend with another, and demonstrate the causal impact of World War II service on postwar wages, particularly for those at the bottom of the wage distribution.The fourth chapter estimates of the full distribution of all national income in Australia for the period 1991 to 2018, and find that in fact inequality of post-tax national income is lower and increased less than inequality of survey-based (post-transfer, disposable) income between 1991 and 2018. Australian inequality is much lower than that of the United States, and similar to that of France, with those at the bottom of the income distribution faring noticeably better in France and Australia than in the US.Finally, in Chapter 5, we estimate pre- and post-tax income distributions for Canada and its provinces from 1982 to 2021. Since the mid-2000s, income inequality has decreased slightly although it remains far above the levels observed in the early 1980s. Across Canadian provinces, Ontario has consistently had higher inequality than Quebec although the gap has closed in recent years. Quebec has the most progressive tax and transfer system. During the pandemic, post-tax income inequality initially fell with large temporary transfer programs, but pre-tax income inequality has increased since then.Cette thèse comprend cinq chapitres sur l'inégalité et la politique fiscale. Le chapitre 1 construit et analyse une nouvelle base de données mondiale sur les taux d’imposition effectifs du capital et du travail, et établit un nouveau fait stylisé : alors que les taux d’imposition effectifs du capital ont baissé depuis 1965 dans les pays développés, ils ont récemment augmenté dans les pays en développement. Dans de nombreux pays, la mondialisation semble avoir soutenu la capacité des gouvernements à taxer le capital. Au chapitre 2, les données sur les dépenses publiques complètent les données du chapitre 1 sur les recettes fiscales, et nous estimons l’incidence des deux sur les distributions globales du revenu national avant impôt, dans le monde entier depuis 1980. Nous constatons que la redistribution augmente avec le développement, mais cela est entièrement dû aux transferts ; la progressivité de l’impôt n’est pas corrélée au revenu par habitant. La redistribution a augmenté dans la plupart des régions du monde, sauf en Afrique et en Europe de l’Est, où elle a stagné. En passant des estimations mondiales aux études sur un seul pays, le chapitre 3 examine le déclin des inégalités au milieu du siècle aux États-Unis d’Amérique. Une nouvelle attention portée aux données d’archives révèle que la baisse des inégalités a favorisé la classe moyenne plus que les travailleurs pauvres, à une exception près : la compression des salaires du milieu du siècle a duré toute la période d’après-guerre. J’explique une tendance générationnelle par une autre et je démontre l’impact causal du service militaire de la Seconde Guerre mondiale sur les salaires d’après-guerre, en particulier pour ceux qui se trouvent au bas de la distribution des salaires. Le quatrième chapitre estime la distribution complète de l’ensemble du revenu national en Australie pour la période 1991-2018 et constate qu’en fait, l’inégalité du revenu national après impôt est plus faible et a moins augmenté que l’inégalité du revenu disponible après transferts entre 1991 et 2018. L’inégalité australienne est bien inférieure à celle des États-Unis et similaire à celle de la France : les personnes au bas de la distribution des revenus s’en sortent sensiblement mieux en France et en Australie qu’aux États-Unis.Enfin, au chapitre 5, nous estimons les distributions de revenus avant et après impôt pour le Canada et ses provinces de 1982 à 2021. Depuis le milieu des années 2000, les inégalités de revenus ont légèrement diminué, bien qu’elles restent bien supérieures aux niveaux observés au début des années 1980. Dans l’ensemble des provinces canadiennes, l’Ontario a toujours connu des inégalités plus élevées que le Québec, bien que l’écart se soit réduit ces dernières années. Le Québec a le système fiscal et de transferts le plus progressif. Pendant la pandémie, les inégalités de revenus après impôt ont d’abord diminué grâce à d’importants programmes de transferts temporaires, mais les inégalités de revenus avant impôt ont augmenté depuis lors