Un tour d'horizon des critères d'évaluation de la diversité biologique

This paper provides a review of different methods for measuring biodiversity, with an effort in making explicit their axiomatic foundations. Then, it broaches some concepts of biodiversity protection, and finally it discusses several specificities in this issue, such as the role played by spatial attributes and by threshold effects.Cet article utilise un exemple simple pour passer en revue des concepts de mesure de la biodiversité, avec un effort pour expliciter leurs fondements axiomatiques. L'article offre ensuite un aperçu des concepts développés pour sa protection, et il s'achève sur une discussion de quelques spécificités du problème, comme la prise en compte de certains attributs spatiaux et d'effets de seuils

Un tour d'horizon des critères d'évaluation de la diversité biologique

Cet article utilise un exemple simple pour passer en revue des concepts de mesure de la biodiversité, avec un effort pour expliciter leurs fondements axiomatiques. L'article offre ensuite un aperçu des concepts développés pour sa protection, et il s'achève sur une discussion de quelques spécificités du problème, comme la prise en compte de certains attributs spatiaux et d'effets de seuils. / This paper provides a review of different methods for measuring biodiversity, with an effort in making explicit their axiomatic foundations. Then, it broaches some concepts of biodiversity protection, and finally it discusses several specificities in this issue, such as the role played by spatial attributes and by threshold effects.ECONOMIE;BIODIVERSITE;CONSERVATION

Strong, bold, and kind : Self-control and cooperation in social dilemmas

Financial support from the Swedish Research Council (Vetenskapsrådet), from Formas through the program Human Cooperation to Manage Natural Resources (COMMONS), and the Ideenfonds of the University of Munich is gratefully acknowledged.We develop a model that relates self-control to cooperation patterns in social dilemmas, and we test the model in a laboratory public goods experiment. As predicted, we find a robust association between stronger self-control and higher levels of cooperation, and the association is at its strongest when the decision maker’s risk aversion is low and the cooperation levels of others high. We interpret the pattern as evidence for the notion that individuals may experience an impulse to act in self-interest—and that cooperative behavior benefits from self-control. Free-riders differ from other contributor types only in their tendency not to have identified a self-control conflict in the first place.PostprintPeer reviewe

Evolutionarily stable conjectures and other regarding preferences in duopoly games

This paper was published by Springer as Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.We study the evolutionary selection of conjectures in duopoly games when players have other regarding preferences, i.e. preferences over payoff distributions. In both the Cournot and Bertrand duopoly games, the consistent conjectures are independent of other regarding preferences. Both duopoly games have evolutionarily stable conjectures that depend on other regarding preferences but that do not coincide with the consistent conjectures. For increasingly spiteful preferences, the evolutionarily stable conjectures implicate low quantities in the Cournot game and high prices in the Bertrand game, whereas the inverse relationships hold for the consistent conjectures. We discuss our findings in the context of ultimate and proximate causation

Politiques publiques et mesures individuelles de protection contre les inondations en France

International audienceIn order to limit damage linked to floods, individual adaptation measures could represent an interesting solution. Indeed, people at flood risk may implement measures that are tailored to their specific situation, which could in turn be less costly and less harmful for the environment than public policies. However, in order to assess the importance of this type of behavior and in order to encourage people to protect themselves against flood risks, it is necessary to understand the mechanisms of adoption of these adaptation behaviors. The aim of this article is twofold: first, to gain a better understanding of the reasons of individual flood prevention, second to discuss the role of different public prevention policies that encourage or hinder the adoption of individual measures. Our empirical analysis is based on semi-structured interviews with a dozen of households and a survey of 331 households in the departments Aude and Var in France. We collected data on existing precautionary measures and the intentions to implement such measures, distinguishing between structural measures (e.g. elevation of buildings or of electric devices), organizational measures (e.g. create living spaces in upper floors), the decision to move out of flood-prone areas and behavioral adaptations (e.g. use meteorological service or avoid taking the car in case of bad weather). We also collected data on exposure, experience of floods, characteristics of housing, costs and perceived efficiency of precautionary measures, risk perception and attitudes towards public policies as well as socio-demographic features. Our analysis shows that flood experience and the perceived self efficacy to implement measures are most important drivers for the adoption of individual measures, next to homeownership. Respondents' perceptions of flood risks and perceived consequences of floods as well as their attitudes towards risks and public flood prevention policies are important additional explanatory factors for people's intentions to invest in precautionary measures. Moreover, we highlight the existence of barriers to the adoption of individual measures, which can be explained by financial or emotional burdens. Our results suggest that individual precautionary measures cannot be considered as substitutes for insurance policies. Moreover, the satisfaction with public flood prevention policies does not play a predominant role in the explanation of the adoption of individual measures. However, we show that regional effects are important which could be linked to the institutional context of flood prevention. Concerning public flood prevention, our analysis shows that the CatNat system does not (completely) crowed out individual action and can thus be complementary to individual measures. Public policies that are aimed at supporting individual precautionary measures could be designed in two ways: first, shortly after flood events, public support should be directed towards those actors whose flood risk perceptions and perceptions of potential consequences are greatest. Second, sustained public support after the crisis management is important and could be tailored to increase information on the efficiency of different precautionary measures and to decrease the financial risk that households take when investing in precautionary measures

Voluntary matching grants can forestall social dumping

The European economic integration leads to increasing mobility of factors, thereby threatening the stability of social transfer programs. This paper investigates the possibility to achieve by means of voluntary matching grants both the optimal allocation of factors and the optimal level of redistribution in the presence of factor mobility. We use a fiscal competition model a la Wildasin (1991) in which states differ in their technologies and preferences for redistribution. We first investigate a simple process in which the regulatory authority progressively raises the matching grants to the district choosing the lowest transfer and all districts respond optimally to the resulting change in transfers all around. This process is shown to increase total production and the level of reditribution. However it does not guarantee that all districts gain, nor that an efficient level of redistribution is attained. Assuming complete information among districts, we first derive the willingness of each district to match the contribution of other districts and we show that the aggregate willingness to pay for matching rates converges to zero when both the efficient level of redistribution and the efficient allocation of factors are achieved. We then describe the ajustment process for the matching rates that will lead districts to the efficient outcome and guarantee that everyone will gain

[Sur les effets des conjectures dans un modèle d'interaction stratégique]

National audienceLes auteurs ont comparé la Pareto efficacité de trois comportements possibles des agents dans un jeu statique : a. les agents décident de façon non coopérative en considérant les actions des autres agents comme données, b. les agents décident de façon non coopérative en faisant des conjectures sur le comportement des autres agents, c. les décisions sont prises par une autorité qui tient compte du bien-être collectif. Les résultats des trois scénarios : l'équilibre de Nash, l'équilibre conjectural et l'optimum de Pareto. Ils prouvent que les signes des externalités, des conjectures et des dérivées croisées de la fonction de profit permettent seuls de classer les actions et les profits

Inhibition of PAI-1 expression in breast cancer carcinoma cells by siRNA at nanomolar range.

Plasminogen activator inhibitor type I (PAI-1) plays a central role in metastatic behavior by increasing cells' migratory capacities as shown in several tumoral cell lines. Moreover, in vivo high expression of this factor helps tumoral growth, both by its role in extracellular matrix remodeling and by favoring angiogenesis. High levels of PAI-1 are correlated with bad prognosis in several cancers, particularly in breast cancer. The effect of PAI-1 upon angiogenesis is also involved in atherosclerosis, in which high levels of PAI-1 expression are observed. Breast carcinoma MDA MB 231 cells are known for both having important metastatic capacities and expressing high levels of PAI-1. We have demonstrated in these cells that the transfection of PAI-1 specific small interfering RNAs (siRNA) specifically inhibited the expression of this factor by 91%. We evaluated siRNA activity by determining PAI-1 mRNA level, as well as intracellular and extracellular PAI-1 protein by using RT Q-PCR, Western blot and ELISA analyses, respectively. Data confirmed inhibition at mRNA levels (primary aim of interference), intracellular protein, and secreted PAI-1, the latter being operative successfully in the cell microenvironment. The lipidic vector Delivery Liposomes System (DLS) used was adapted to siRNA delivery as observed by particle size distribution analysis, confocal microscopy and transfection into MDA MB 231, in the presence of serum. SiRNA activity was clearly detected at concentrations as low as 10 nM. Moreover, the low cytotoxicity of this vector makes it a good candidate for future in vivo siRNA delivery

Identifying consensus on coastal lagoons ecosystem services and conservation priorities for an effective decision making : a Q approach

Coastal lagoons ecosystems, while representing benefits for the local populations, have been subjected to high anthropogenic pressures for decades. Hence, conservation measures of these ecosystems are urgently needed and should be combined with their sustainable uses. To address these issues, new research avenues for decision support systems have emphasized the role of the assessment of ecosystem services for establishing conservation priorities by avoiding monetarization approaches. These approaches, because they flatten the various values of nature by projecting them on the single monetary dimension, are often rejected by the stakeholders. We undertake a Q analysis to identify levels of consensus and divergence among stakeholders on the prioritization of ecosystem services provided by two French Mediterranean coastal lagoons areas. The results highlighted that there is a strong consensus among categories of stakeholders in the study sites about the paramount importance of regulation and maintenance services. Three groups of stakeholders, each sharing the same points of view regarding ecosystem services conservation, were identified for each study site. As a non-monetary valuation, Q methodology is very instrumental for the new pluralistic approach of decision support by capturing the values expressed by the stakeholders, without triggering a rejection reflex due to the monetarization

Markov interactions in a class of dynamic games

Dynamic games, Markov perfect equilibrium, Open-loop Nash equilibrium, Markov interactions, Efficiency, C73, D92, L16,