Premières Représentations.

Transcript of PREMIÈRES REPRÉSENTATIONS by Georges Boyer, appearing in LE PETIT JOURNAL, 23 avril 1910, p. 3. (Mariotte

Sécurité routière : efficacité, subvention et réglementation

Dans cet article nous présentons une analyse économique de la sécurité routière en mettant l’accent sur les inefficacités engendrées par les externalités et le risque moral. Nous abordons également des mécanismes susceptibles de contrer les inefficacités tels les taxes et subsides et la réglementation gouvernementale.L’utilisation des taxes et subsides est pratiquement impossible puisque le gouvernement ne peut observer directement les activités de prévention des individus. Le gouvernement doit donc s’en remettre, par le biais de la réglementation, à des interventions directes sur la probabilité d’accident et sur le montant de perte en cas d’accident. Nous présentons une formule d’évaluation des actions gouvernementales permettant de calculer la rentabilité sociale des projets publics et de comparer divers projets gouvernementaux. Nous démontrons que la prise en compte de l’aversion au risque augmente la rentabilité des projets publics et peut affecter la classification des projets.In this paper, we present an economic analysis of road safety emphasizing market failures due to externalities and moral hazard. We also examine governmental actions such as taxes and subsidies and regulation which may reduce inefficiencies.The use of taxes and subsidies is practically impossible since the government cannot observe individual's self-protection activities. However the government, by regulation, can intervene directly on the accident probability and on the amount of loss when accident occurs. We present a formula which permits the evaluation of governmental projects of intervention. We show that risk aversion increases the net social benefits of public projects and can affect the ranking of the projects

Riscophobie et étalement à moyenne constante : analyse et applications

L’objet de cet article est de montrer que, pour la perspective aléatoire caractérisée par la probabilité p de perdre une valeur h, il existe une mesure adéquate des variations dans le risque engendrées par des variations comparables de p et h, ce qui permet d’isoler le facteur risque et de prédire le comportement des agents riscophobes. Cette mesure résulte d’une application du concept d’étalement à moyenne constante (mean-preserving spread) développé par Rothschild et Stiglitz. Le résultat principal est à l’effet qu’un agent riscophobe préférera toujours une diminution de la perte à une baisse comparable de la probabilité de perte. Nous appliquons ce résultat simple à diverses situations : assurance-chômage, réglementation par enquêtes et amendes, contrôle des prix et des salaires, sécurité routière, stationnement illégal, loteries, autoassurance vs autoprotection. Enfin nous dérivons une mesure de variation compensatoire de richesse reliée au degré de riscophobie.The purpose of this paper is to show that, for the risky situation caracterized by the probability p of losing an amount h, there exists an adequate measure of the risk variations caused by equivalent changes in p and h. This follows from an application of the concept of mean-preserving spread developed by Rothschild and Stiglitz. The main result—that a risk averse agent will always prefer a decrease in the amount of loss to an equivalent reduction in the probability of loss—is applied to different problems ranging from unemployment insurance, double parking, and autosafety regulation to price controls, lotteries and the choice of self insurance and self protection. Finally, we derive a measure of compensation related to the degree of risk aversion

Sécurité routière : efficacité, subvention et réglementation

In this paper, we present an economic analysis of road safety emphasizing market failures due to externalities and moral hazard. We also examine governmental actions such as taxes and subsidies and regulation which may reduce inefficiencies. Dans cet article nous présentons une analyse économique de la sécurité routière en mettant l’accent sur les inefficacités engendrées par les externalités et le risque moral. Nous abordons également des mécanismes susceptibles de contrer les inefficacités tels les taxes et subsides et la réglementation gouvernementale.

Riscophobie et étalement à moyenne constante : analyse et applications

The purpose of this paper is to show that, for the risky situation caracterized by the probability p of losing an amount h, there exists an adequate measure of the risk variations caused by equivalent changes in p and h. This follows from an application of the concept of mean-preserving spread developed by Rothschild and Stiglitz. The main result—that a risk averse agent will always prefer a decrease in the amount of loss to an equivalent reduction in the probability of loss—is applied to different problems ranging from unemployment insurance, double parking, and autosafety regulation to price controls, lotteries and the choice of self insurance and self protection. Finally, we derive a measure of compensation related to the degree of risk aversion. L’objet de cet article est de montrer que, pour la perspective aléatoire caractérisée par la probabilité p de perdre une valeur h, il existe une mesure adéquate des variations dans le risque engendrées par des variations comparables de p et h, ce qui permet d’isoler le facteur risque et de prédire le comportement des agents riscophobes. Cette mesure résulte d’une application du concept d’étalement à moyenne constante (mean-preserving spread) développé par Rothschild et Stiglitz. Le résultat principal est à l’effet qu’un agent riscophobe préférera toujours une diminution de la perte à une baisse comparable de la probabilité de perte. Nous appliquons ce résultat simple à diverses situations : assurance-chômage, réglementation par enquêtes et amendes, contrôle des prix et des salaires, sécurité routière, stationnement illégal, loteries, autoassurance vs autoprotection. Enfin nous dérivons une mesure de variation compensatoire de richesse reliée au degré de riscophobie.

Fluorescence-Guided Stereotactic Biopsy: A Proof-of-Concept Study

Introduction: Histopathological diagnoses are often necessary for treating neuro-oncology patients. However, stereotactic biopsy (STB), a common method for obtaining tissue from deep or eloquent brain regions, fails to yield diagnostic tissue in approximately 10% of cases. This can delay initiation of treatment and may result in further invasive procedures for patients. Here, we evaluate if coupling in vivo optical imaging with a STB system can identify diagnostic tissue at the time of biopsy. Methods: A minimally invasive fiber optic imaging system was developed by coupling a 0.65mm diameter fiber optic fluorescence microendoscope to a STB system. Human glioma cells were transduced for stable expression of blue fluorescent protein (U251-BFP) and utilized for in vitro and in vivo experiments. In vitro, blue fluorescence was confirmed, and tumor cell delineation by sodium fluorescein (FNa) was quantified with fluorescence microscopy. Rodent xenografts implanted with U251-BFP cells (n=4) were utilized for in vivo experiments. Five weeks post-implantation, xenografts received 5-10mg/kg intravenous FNa and underwent craniotomies overlying the tumor implantation site and contralateral normal brain. A clinical STB needle containing our 0.65mm imaging fiber was passed through each craniotomy and images were collected. Fluorescence images from regions of interest (ROI) ipsilateral and contralateral to tumor implantation were analyzed. Results: Live-cell fluorescence imaging confirmed blue fluorescence from transduced tumor cells and revealed a strong correlation between tumor cells quantified by blue fluorescence and FNa contrast (R2=0.91, p\u3c0.001). Normalized to background, in vivo FNa fluorescence intensity was significantly greater from tumor regions, verified by blue fluorescence, compared to contralateral brain in all animals (60.65± 17.35 %, p\u3c0.001). Fluorescein fluorescence was not significantly greater from the tumor margin compared to normal brain (p =0.096). Biopsies obtained from regions of strong fluorescein contrast were histologically consistent with tumor. Conclusion: We found in vivo fluorescence imaging with a STB needle containing a submillimeter diameter fluorescence microendoscope provided direct visualization of neoplastic tissue in an animal brain tumor model prior to biopsy. This was confirmed in vivo and by post-hoc histological assessment. In vivo fluorescence guidance may improve the diagnostic yield of stereotactic biopsies

Does insurance fraud in automobile theft insurance fluctuate with the business cycle?

[[abstract]]Financial institutions face various cyclical risks, but very few studies have analyzed the cyclicality of operational risk. External fraud is an important operational risk faced by insurers. In this research, we analyze the empirical relationship between insurance fraud and business cycle and we concentrate our study on two insurance contracts that may create an incentive to defraud. We find that residual insurance fraud exists both in the contract with replacement cost endorsement and the contract with no-deductible endorsement in the Taiwan automobile theft insurance market. These results are consistent with previous literature on the relationship between fraud activity and non-optimal insurance contracting. We also show that the severity of insurance fraud is countercyclical. Fraud is stimulated during periods of recession and mitigated during periods of expansion. Although this last result seems intuitive, our contribution is the first to measure its significance.[[notice]]補正完畢[[incitationindex]]SSCI[[booktype]]紙本[[booktype]]電子