Biased Judges: Evidence from French Environmental Cases

Using an original database of 614 judgements in the French supreme courts from 1956 to 2010, we test for possible biases in judges’ decisions in the field of environmental accidents, focusing on a difference in treatment between private parties and the government as litigant. Two separate institutions deal with environmental cases in France, namely the Conseil d’Etat (Supreme Administrative Tribunal) for public utilities and central and local government, and the Cour de cassation (Supreme Civil Court) for private firms. We run bivariate Probit regressions to explain pro-defendant decisions and reversals of decisions. Overall, courts treat plaintiffs and defendants differently. A pro-defendant decision and a reversal of decision areless likely to occur: (i) when the appeal is initiated by the defendant rather than by the plaintiff; (ii) in the Conseil d’Etat ´ rather than in the Cour de cassation. The Conseil d’Etat ´ is harsher with defendants than the Cour de cassation. These results could be indicative of a bias of the lower administrative tribunals in favor of public utilities and/or the government

Short-time asymptotics for marginal distributions of semimartingales

We study the short-time asymptotics of conditional expectations of smooth and non-smooth functions of a (discontinuous) Ito semimartingale; we compute the leading term in the asymptotics in terms of the local characteristics of the semimartingale. We derive in particular the asymptotic behavior of call options with short maturity in a semimartingale model: whereas the behavior of \textit{out-of-the-money} options is found to be linear in time, the short time asymptotics of \textit{at-the-money} options is shown to depend on the fine structure of the semimartingale

Generation and maturation of a vortex ring in non-Newtonian fluids

Vortex rings are coherent structures that dominate the dynamics of many flows. They are present in a wide range of situations : in industrial mixing systems (in the vicinity of the agitation moving blades), but also in nature during the ejection of volcanic gas or in the wakes behind insects, birds and fishes, where a periodic release of vortex rings is observed. In this work we study the formation and maturation of a vortex ring in non-Newtonian fluids, with a special focus on shear-thinning fluids and yield stress fluids. The experimental system consists of a cylindrical tube-piston device whose lower part is immersed in a tank containing the fluid. Particle Image Velocimetry (PIV) is used to analyze the flow. A preliminary study is realized with Newtonian fluids to validate the device the device. It allows exploration of low Reynolds numbers configurations, showing the existence of a vortex ring for Reynolds numbers as low as 10. This work is then extended to non-Newtonian fluids, using shear-thinning Xanthane solutions (behavior index between 0.6 and 1) and two yield stress fluids (Carbopol) with yield stress between 1 and 3 Pa. The results are analyzed in terms of vorticity fields and of characteristics of the ring (velocity and geometry). T, the time evolution of these variables as a function of the characteristics of the fluid is reported. Then we focus on the rolling up and detachment mechanisms for the larger Reynolds numbers while, at low Reynolds numbers, the investigation is focused on the more complicated dynamical mechanisms involved, taking into account the influence of the nature of the fluid on this dynamics

Étude expérimentale d'un anneau tourbillonnaire en fluide newtonien et non newtonien en régime faiblement inertiel

Cette thèse est une étude expérimentale de la formation et de la maturation d un anneau tourbillonnaire. Elle porte sur les écoulements faiblement inertiels (Reynolds : 5 à 500) en fluide newtonien puis non newtonien. Les anneaux sont générés par un système cylindre-piston. Ils sont analysés par visualisation et par vélocimétrie par images de particules (PIV). La dynamique en fluide newtonien à faible nombre de Reynolds se révèle plus complexe que celle à grands Reynolds avec l apparition d un anneau secondaire contrarotatif. Les résultats obtenus en fluide rhéofluidifiant montrent l influence de l indice de comportement ainsi que les zones de comportement rhéofluidifiant et newtonien. Les explorations en fluides viscoplastique et viscoélastique montrent la formation d un ou plusieurs anneaux secondaires contrarotatifs, qui diffèrent dans leur formation et leur dynamique des anneaux observés en fluide newtonien et que l on associe aux propriétés physiques intrinsèques du fluide.The present work is an experimental study of the generation and the maturation of vortex rings, in order to characterize their structure and their global dynamics for small to moderate Reynolds numbers (between 5 and 500) in Newtonian and non-Newtonian fluids. The experimental set-up consists of a vertical cylindrical piston-tube system with the lower part immersed in a filled tank. Measurement campaigns have been carried out using dye visualization and Particle Image Velocimetry (PIV). A first part of the work is focussed on Newtonian fluid and allows the dynamics at low Reynolds numbers to be investigated qualitatively and quantitatively. This dynamics turns out to be more complex than the one classically observed at high Reynolds numbers, and is characterized by the production of a counter-rotating secondary vortex ring. The results obtained for shear thinning fluids show the influence of the power-law index on the development and the propagation of the ring. The computation of the shear rate field allows the results to be analyzed in terms of shear thinning and Newtonian regions. Finally a preliminary investigation for viscoplastic and viscoelastic fluids has been performed. In both cases, it is shown that one (for viscoplastic fluids) or several (for viscoelastic fluids) counter-rotating secondary vortex rings are generated, a phenomenon that can be associated with the intrinsic physical properties of the fluid. All these results provide several perspectives of study in the field of vortex rings dynamics in the weakly inertial regimes.TOULOUSE-INP (315552154) / SudocSudocFranceF

Experimental study of low inertia vortex rings in shear-thinning fluids

The present work investigates experimentally the dynamics of vortex rings in shear-thinning fluids at low generalized Reynolds numbers, with a focus on the range from 300 down to 30. The experimental apparatus consists of a vertical cylinder-piston system with the lower part immersed in a tank filled with the liquid. Particle image velocimetry is used to analyze the influence of the non-Newtonian nature of the fluid on the generation, propagation, and eventual dissipation of vortex rings. The results show that shear-thinning controls the generation phase, whereas the vortex ring subsequent evolution is independent of the power-law index. In particular, it is found that the final dissipation stage is characterized by a flow dynamics which tends ultimately to a regime at a constant viscosity corresponding to the Newtonian plateau. This reveals the role of the Carreau number and of the Reynolds number based on this specific viscosity as relevant control parameters for this last stage

The consequences of greater net price transparency for innovative medicines in Europe: Searching for a consensus

The merits of greater or lesser net price transparency (NPT) has been a topic for discussion for many years across business and industry in general. However, in the past few years, the debate on NPT of innovative medicines has intensified, with organisations such as the United Nations (UN), the World Health Organization (WHO) and the Organisation for Economic Co-operation and Development (OECD) leading calls for greater transparency in the pharmaceutical sector, specifically focused on prices. In May 2019 the World Health Assembly (WHA) approved a resolution to support the greater public disclosure of prices and research and development (R&D) costs for both medicines and other health products supported by several European and non-European governments. To contribute to the international debate on the transparency of medicine prices in Europe, Merck Sharp & Dohme (MSD) asked Charles River Associates (CRA) to curate a panel of experts to develop evidence on the impact of greater NPT of innovative medicines. Professor Walter Van Dyck1 and Professor Massimo Riccaboni2 were asked by CRA to lead this research, supported by a wider panel of 10 experts from a range of European markets. A structured literature review was first conducted to summarise the theoretical consequences of greater NPT. This was supplemented with a survey of national payers and payer experts3 from a range of European markets. This was used as pre-read information for an expert advisory board of 12 economic and health economic experts representing 12 countries selected to give a range of market sizes, national income and payer approaches. The debate and the consensus reached by the advisory board have been summarised in this report. In addition, a computational model has been developed by two key investigators to provide new, empirical evidence to illustrate the impact of NPT on different European markets

Controlling Product Risks When Consumers are Heterogeneously Overconfident: Producer Liability vs. Minimum Quality Standard Regulation

Contributing to the literature on the consequences of behavioral biases for market outcomes and institutional design, we contrast producer liability and minimum quality standard regulation as alternative means of social control of product-related torts when consumers are heterogeneously overconfident about the risk of harm. We elucidate the role of factors shaping the relative desirability of strict liability vis-à-vis minimum quality standard regulation from a social welfare standpoint. We also clarify when and why joint use of strict liability and minimum quality standard regulation welfare dominates the exclusive use of either mode of social control of torts

La combinaison de réglementation et de responsabilité civile environnementale : manifestations et efficacité dans le droit français

A l'origine de l'étude se trouve un paradoxe ; alors que l'analyse économique met en avant la nécessité de réglementer les activités dangereuses pour l'environnement et les hommes, on voit émerger dans la plupart des pays développés des systèmes hybrides, de plus en plus complexes, mêlant réglementation et responsabilité civile pour traiter ces problématiques. Pour expliquer ce décalage entre théorie économique et évolution juridique, la première partie de la thèse revient sur les fondements de l'économie de l'environnement et propose une approche opérationnelle qui permet de déterminer l'efficacité de chaque institution – propriété, responsabilité et réglementation – selon les caractéristiques des situations et des risques envisagés. Ce faisant, elle aboutit à la conclusion que seul un système combinant les institutions de la responsabilité civile et de la réglementation publique des activités risquées est à même de promouvoir le développement tout en maîtrisant ses dangers. Confrontant cette théorie nouvelle au cas français, la thèse met en évidence les interactions des deux acteurs clés du système, le juge et le régulateur, et observe l'influence positive et réciproque de l'un sur l'autre. A l'aide d'une base de données unique regroupant l'ensemble des litiges environnementaux traités devant la Cour de Cassation et le Conseil d'Etat au cours des soixante dernières années, la seconde partie éclaircit les rôles de chaque institution et démontre que loin d'être paradoxal, le système français a évolué spontanément vers davantage de cohérence et d'efficacité grâce à l'information diffusée par les tribunaux.Most developed countries use a mix of public regulation and civil liability to cope with environmental risks and damages. Though, a vast majority of economic scholars tend to favour a regime of pure regulation in the domain of environmental accidents, arguing that liability cannot provide incentives for polluters and potential injurers to take socially desirable care. Our dissertation aims to answer this paradox between legal reality and economic theory. In the first part of our study, we develop an operational approach of the concept of externality based on the concrete characteristics that represent an impediment to individual cooperation and thus to the application of property rights. This method allows us to compare the efficiency of public regulation and civil liability and to reach a clear-cut conclusion: in the most complex situations, neither regulation nor liability is able to encourage socially desirable care and to ensure complete compensation for victims at the same time. In these situations, joint use of both legal instruments might be superior to regulation or liability alone because it enables each instrument to overcome the inefficiencies of the other, through interactions and informational transfers occurring between judges and regulators. In the second part, we test our theory in the French case. To observe the existence of institutional interactions between judges and regulators, we create a unique dataset gathering the whole litigations on environmental accidents from cases adjudicated by the Court of Cassation since 1956. Our econometric results show that joint use of regulation and liability emerged to promote economic efficiency of the legal system

Correction Activities by France’s Supreme Courts and Control over their Dockets

International audienceThe aim of this paper is to observe how supreme courts use their discretionary power over their dockets to correct appellate courts’ decisions relative to their own interpretation of the law. There are two supreme courts in France, the Conseil d’État for the administrative branch, and the Cour de Cassation for the civil one. In both courts, at different dates though, a reform took place that gave them discretionary control over their dockets. Hence, a difference in the supreme courts’ decisions might be due to either different correction activities, selection strategies, or both. Accordingly, it is necessary to distinguish between them before drawing any conclusions about supreme courts’ behaviors. We develop an econometric approach to assess whether the correction activities are similar between supreme courts, and whether these activities are affected when the supreme courts can select cases. Using an original database of all environmental cases determined by the supreme courts between 1956 and 2010, we rely on a counterfactual approach to compare cases across the courts before and after the reforms. Our study concludes that correction activities do not differ across the courts as long as they are submitted to the same selection rule. We also find that the supreme courts use the possibility of selection to increase their pro-plaintiff correction activities in a way that affects the overall probability of success of plaintiffs and defendants

Génération et maturation d’un anneau tourbillonnaire en fluide non newtonien

On présente ici l’étude de la formation et de la maturation d'un anneau tourbillonnaire en fluide rhéofluidifiant. Le dispositif expérimental consiste en un système tube cylindrique-piston dont la partie basse est immergée dans une cuve. Une méthode de vélocimétrie par images de particules (PIV) est utilisée pour analyser l’écoulement. Une première étude a permis de valider le dispositif en fluide newtonien puis d’explorer le domaine des faibles nombres de Reynolds, montrant ainsi l’existence d’un anneau tourbillonnaire pour des Reynolds aussi faibles que 10. Ce travail a été étendu aux fluides non newtoniens et on présente ici les résultats obtenus sur des fluides rhéofluidifiants ayant des indices de comportement compris entre 0.5 et 1. Les résultats obtenus sont analysés en terme de champs de vorticité et de caractéristiques de l’anneau (vitesse de propagation et diamètre) et on examine l’évolution de ces variables en fonction des caractéristiques des fluides. On s’intéresse également au régime d’enroulement/détachement de l’anneau pour les plus grands nombres de Reynolds ainsi qu’à la dynamique plus complexe qui se met en place pour les faibles nombres de Reynolds et on examine l’influence du caractère rhéofluidifiant sur cette dynamique