A contribution of experimental economics toward characterization of the use of market power in oligopolisitc markets

Despite the numerous researches about imperfect competition, the market power remains difficult to quantify using traditional economics methods. In this paper, we propose an experimental economics design and outline some ways of analysis of its results toward characterization of the use of market power. A simple system with two regions and a limited interconnection transfer capacity allocated by an implicit auction is studied. Depending on the experiments two or three subjects share equitably the production capacity in one region, while the production capacity is equitably shared among 5 subjects leading to a more competitive situation in the second one. In both regions, we observe a market price that is different from the theoretical results allowing a quantification of the use of market power. Results are also analyzed based on a characterization of the subjects' behaviour. Further the impact of subjects' behaviour on the market price evolution is described.experimental economics, market power, electricity markets, oligopolistic markets

A contribution of experimental economics toward characterization of the use of market power in oligopolisitc markets

International audienceDespite the numerous researches about imperfect competition, the market power remains difficult to quantify using traditional economics methods. In this paper, we propose an experimental economics design and outline some ways of analysis of its results toward characterization of the use of market power. A simple system with two regions and a limited interconnection transfer capacity allocated by an implicit auction is studied. Depending on the experiments two or three subjects share equitably the production capacity in one region, while the production capacity is equitably shared among 5 subjects leading to a more competitive situation in the second one. In both regions, we observe a market price that is different from the theoretical results allowing a quantification of the use of market power. Results are also analyzed based on a characterization of the subjects' behaviour. Further the impact of subjects' behaviour on the market price evolution is described

La contrainte Increasing NValue

National audienceCet article introduit la contrainte Increasing NValue, qui restreint le nombre de valeurs distinctes affectées à une séquence de variables, de sorte que chaque variable de la séquence soit inférieure ou égale à la variable la succédant immédiatement. Cette contrainte est une spécialisation de la contrainte NValue, motivée par le besoin de casser des symétries. Il est bien connu que propager la contrainte NValue est un problème NP-Difficile. Nous montrons que la spécialisation au cas d'une séquence ordonnée de variables rend le problème polynomial. Nous proposons un algorithme d'arc-consistance ayant une complexité temporelle en O(sum D), où sum D est la somme des tailles des domaines. Cet algorithme est une amélioration significative, en termes de complexité, des algorithmes issus d'une représentation de la contrainte Increasing NValue à l'aide d'automates ou de la contrainte SLIDE. Nous utilisons notre contrainte dans le cadre d'un problème d'allocation de ressources

Designing work organization based on ''profession'' collectives and ''inter-profession'' relations

International audienceThe aim is to show that the design of organizational structure can be enhanced through debates about work among profession-specific collectives and through the development of relations between several professions. We are carrying out several ergonomic interventions in projects with multidisciplinary teams working in occupational health departments. We shall present two cases of occupational health departments whose contexts, in terms of multidisciplinary team composition are different. The intervention- related difficulties encountered during organizational design projects based on collective activity lead us to question future methodologies

Les activités des médecins du travail dans la prévention des TMS : ressources et contraintes

MSD represents the primary cause of occupational illness and the occupational health physician would appear to be a determining stakeholder in prevention. The studies of risk factors of MSD are important but the studies of intervention are limited. The objective of our research is double: understand the practices of occupational health physician and give the means of activity development. Theoretical framework is multidisciplinary approach about activity analysis. The problematic is to produce knowledge of activity of occupational health physicians to take into account their activity in the debate of professional evolution and pluridisciplinarity in health of work. The disciplinary skills of each equip of research produce some methods. Fifty physicians participate in our research. We have observed during 60 day with ergonomics methods, notably 200 sequences of medical consultation with protocol to record data, confirmed by institutions of protection of physician profession and protection of data. Some types of interview are realized (65): semi-directive, clarification, simple self-confrontation, cross self-confrontation. Furthermore, our research is based on the objective to develop the activity of occupational health physicians. To do this, we set up four groups of volunteer occupational health physicians. The discussion of groups is based on objective data of activity (14 discussion sessions) and on instruction of double (15 discussions sessions). All equips of our research have building a common reference to facilitate the data exploitation. Each equip has written one or some articles (in annex of report) to keep this specificity of data production based of disciplinary approach. The first result is that there are some skills of occupational health physicians to make prevention. Someone physicians prefer to realize their action in consultation while the others prefer make intervention in company. The professionals styles of physicians according to the gender building with experience and training depend on context of company, legislative prevention system, relationship between stakeholders and operators, which facilitate or slow down to built the room of maneuver to exercise these professional styles. The activity of physician can be to hamper in certain conditions. The occupational health physicians are the only one to follow the operators, the story of company and relationships of stakeholders, the evolution of health and work. They use their knowledge about work in company to help operator to understand the relation between work and health. They mobilize the words using by operators in consultation, with respected the medical secret, to modify the stakeholders representation of the interaction between work and health. In the other words, it is impossible to separate the individual approach and collective approach in prevention activity of occupational health physician. These different approaches organize the actions of physician. The discussion of research led to questioning the legislative evolution and comparing our French system with de others system like Quebec system.Les TMS constituent l'une des premières maladies professionnelles et les médecins du travail jouent un rôle important dans la prévention. Aujourd'hui les connaissances sur les facteurs de risque à l'origine de cette pathologie font l'objet de débats sur la prévention des TMS. Les recherches ont besoin d'évoluer vers une meilleure connaissance des modalités de prise en charge de ce risque par les professionnels de la prévention. L'objectif de notre recherche est donc double : comprendre les pratiques des médecins du travail et participer au développement de leur activité de prévention. Notre cadre théorique multidisciplinaire (ergonomie, clinique du travail, sociologie du travail) est celui de l'analyse du travail. Notre problématique est la production de connaissances sur l'activité réelle du médecin afin de contribuer au débat sur les évolutions de leur métier et la pluridisciplinarité en santé au travail. Plusieurs méthodologies ont été mises en œuvre selon les compétences et les disciplines de chaque équipe de recherche. Une cinquantaine de médecins volontaires ont participé à notre recherche. Nous avons fait plus de 60 jours d'observation ergonomique du travail sur le terrain, dont 200 observations de consultation avec un protocole validé par le conseil de l'ordre et la CNIL. Différentes formes d'entretiens (au total 65) ont été réalisés (semi-directif, d'explicitation, d'auto-confrontation simple et croisé). Afin de contribuer au développement de l'activité de prévention des médecins du travail, nous avons constitué quatre groupes de pairs qui ont pu échanger sur les traces de leur activité réelle (au total, 14 réunions collectives) et à partir des méthodologies d'instruction du sosie (au total, 15 réunions collectives). Nos équipes de recherche ont partagé un référentiel commun afin de faciliter l'exploitation des données. Pour ne pas perdre la spécificité de chaque discipline, chaque équipe a écrit un ou plusieurs textes (en annexes du rapport) qui constituent la base d'un document de synthèse. Premier résultat, il existe plusieurs manières et façons de faire de la prévention des TMS chez les médecins du travail. Certains médecins privilégient une action en consultation alors que d'autres sont plus dans une action en entreprise. Mais ces styles, s'ils correspondent à des postures professionnelles construites avec l'expérience et le parcours de formation, sont très dépendants du contexte de l'entreprise, des dispositifs légales de prévention et du type de relations avec les salariés, les acteurs de l'entreprise et de la prévention, qui rendent plus ou moins possibles leurs mises en œuvre. L'activité du médecin dans certaines conditions est empêchée. Les médecins du travail sont les seuls intervenants de la prévention à tenir dans la continuité l'histoire de l'entreprise, des relations, de la santé. Ils ramènent leurs connaissances sur le travail pour aider le salarié à faire les liens entre le travail et la santé. Ils mobilisent la parole des salariés issue de la consultation dans les espaces d'échanges publics de l'entreprise, tout en respectant le secret médical, afin de modifier la représentation des acteurs sur les liens travail-santé. Autrement dit, il est impossible dans l'activité de prévention du médecin de délier l'approche individuelle et collective car celles-ci sont sans arrêt articuler et combiner. Cela conduit à s'interroger sur l'évolution de la loi et à comparer les pratiques avec d'autres systèmes de prévention, comme celui du Québec

Heterogeneous adjustments of labor markets to automation technologies

This paper examines the labor market adjustments to four automation technologies (i.e. robots, communication technology, information technology, and software/database) in 227 regions across 22 European countries from 1995 to 2017. By constructing a measure of technology penetration, we estimate changes in regional employment and wages affected by automation technologies along with the reallocation of workers between sectors. We find that labor market adjustments to automation technologies differ according to i) the technology involved, ii) the sector of penetration, iii) the sectoral composition of the region, and iv) the region’s technological capabilities. These adjustments are driven largely by the reallocation of low-paid workers across sectors

La contrainte Increasing NValue

National audienceCet article introduit la contrainte Increasing NValue, qui restreint le nombre de valeurs distinctes affectées à une séquence de variables, de sorte que chaque variable de la séquence soit inférieure ou égale à la variable la succédant immédiatement. Cette contrainte est une spécialisation de la contrainte NValue, motivée par le besoin de casser des symétries. Il est bien connu que propager la contrainte NValue est un problème NP-Difficile. Nous montrons que la spécialisation au cas d'une séquence ordonnée de variables rend le problème polynomial. Nous proposons un algorithme d'arc-consistance ayant une complexité temporelle en O(sum D), où sum D est la somme des tailles des domaines. Cet algorithme est une amélioration significative, en termes de complexité, des algorithmes issus d'une représentation de la contrainte Increasing NValue à l'aide d'automates ou de la contrainte SLIDE. Nous utilisons notre contrainte dans le cadre d'un problème d'allocation de ressources

The Employment Impact of Emerging Digital Technologies

This paper measures the exposure of industries and occupations to 40 digital technologies that emerged over the past decade and estimates their impact on European employment. Using a novel approach that leverages sentence transformers, we calculate exposure scores based on the semantic similarity between patents and ISCO-08/NACE Rev.2 classifications to construct an open–access database, ‘TechXposure’. By combining our data with a shift–share approach, we instrument the regional exposure to emerging digital technologies to estimate their employment impact across European regions. We find an overall positive effect of emerging digital technologies on employment, with a one-standard-deviation increase in regional exposure leading to a 1.069 percentage point increase in the employment-to-population ratio. However, upon examining the individual effects of these technologies, we find that smart agriculture, the internet of things, industrial and mobile robots, digital advertising, mobile payment, electronic messaging, cloud storage, social network technologies, and machine learning negatively impact regional employment

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Encephalopathy induced by Alzheimer brain inoculation in a non-human primate.

Alzheimer's disease is characterized by cognitive alterations, cerebral atrophy and neuropathological lesions including neuronal loss, accumulation of misfolded and aggregated β-amyloid peptides (Aβ) and tau proteins. Iatrogenic induction of Aβ is suspected in patients exposed to pituitary-derived hormones, dural grafts, or surgical instruments, presumably contaminated with Aβ. Induction of Aβ and tau lesions has been demonstrated in transgenic mice after contamination with Alzheimer's disease brain homogenates, with very limited functional consequences. Unlike rodents, primates naturally express Aβ or tau under normal conditions and attempts to transmit Alzheimer pathology to primates have been made for decades. However, none of earlier studies performed any detailed functional assessments. For the first time we demonstrate long term memory and learning impairments in a non-human primate (Microcebus murinus) following intracerebral injections with Alzheimer human brain extracts. Animals inoculated with Alzheimer brain homogenates displayed progressive cognitive impairments (clinical tests assessing cognitive and motor functions), modifications of neuronal activity (detected by electroencephalography), widespread and progressive cerebral atrophy (in vivo MRI assessing cerebral volume loss using automated voxel-based analysis), neuronal loss in the hippocampus and entorhinal cortex (post mortem stereology). They displayed parenchymal and vascular Aβ depositions and tau lesions for some of them, in regions close to the inoculation sites. Although these lesions were sparse, they were never detected in control animals. Tau-positive animals had the lowest performances in a memory task and displayed the greatest neuronal loss. Our study is timely and important as it is the first one to highlight neuronal and clinical dysfunction following inoculation of Alzheimer's disease brain homogenates in a primate. Clinical signs in a chronic disease such as Alzheimer take a long time to be detectable. Documentation of clinical deterioration and/or dysfunction following intracerebral inoculations with Alzheimer human brain extracts could lead to important new insights about Alzheimer initiation processes