A characterization of the single-peaked domain

We provide in this paper two properties that are both necessary and sufficient to characterize the domain of single-peaked preference profiles. This characterization allows for a definition of single-peaked preference profiles without using an ad hoc underlying order of the alternatives and also sheds light on the structure of single-peaked profiles. Considering the larger domain of value-restricted preference profiles (Sen, Econometrica 34:491–499, 1966) we also provide necessary and sufficient conditions for a preference profile to be single-caved or group-separable. Our results show that for single-peaked, single-caved and group-separable profiles it is sufficient to restrict to profiles containing of either three individuals and three alternatives or two individuals and four alternatives.     

Application of ordinal correspondence analysis for submerged aquatic vegetation monitoring

The European Water Framework states that macrophyte communities (seaweeds and seagrass) are key indicators of the ecological health of lagoons. Furthermore, the restoration of these communities, especially the Zostera meadows, is one of the main objectives of the Berre lagoon restoration plan. Consequently, a monitoring programme of the main macrophyte species still present in the lagoon was initiated in 1996. This monitoring resulted in a sequence of 11 spatially structured annual tables consisting of the observed density of these species. These tables are processed in this study. First, we specify the principles of Beh's ordinal correspondence analysis (OCA), designed for ordered row/column categories, and compare this method to classical correspondence analysis (CA). Then, we show that OCA is straightforwardly adaptable for processing a sequence of ordered contingency tables like ours. Both OCA and CA are afterwards used to reveal and test the main patterns of spatio-temporal changes of two macrophyte species in the Berre lagoon: Ulva and Zostera. The results we obtained are compared and discussed.     

Évaluer les pratiques des entreprises en matière de travail décent: une analyse des méthodologies de notation ESG

Les agences de notation spécialisées dans l‘évaluation des pratiques des entreprises en matière environnementale, sociale et de gouvernance (ESG) sont des partenaires importants pour les acteurs de l'investissement responsable, qu'elles alimentent en données extrafinancières. Si la question des indicateurs ESG a déjà été traitée dans la littérature, la façon d‘évaluer le travail décent est peu documentée. Les auteurs observent les pratiques de six agences de notation ESG pour comprendre comment ces organismes mesurent et évaluent la performance en matière de travail décent, et avec quelles difficultés, et pour déterminer si l'investissement responsable et les notations ESG peuvent véritablement promouvoir le travail décent dans les entreprises.     

Quantitative risk assessment of rabies being introduced into mainland France through worldwide noncommercial dog and cat movements

France has been rabies-free among nonflying mammals since 2001. Despite this status, the rabies virus has been introduced several times through noncommercial pet movements, posing a threat of infection by this 100%-lethal zoonosis among local animal and human populations. To quantify the risk of rabies being introduced through worldwide noncommercial dog and cat movements, we performed a quantitative risk assessment using stochastic scenario tree modeling. The mean annual probability of at least one rabies introduction incident was 0.35 (median: 0.24, 90% prediction interval (PI) [0.04; 0.98]) and the mean annual number of rabies-infected pets introduced through pet movements was 0.96 (median: 0.27, 90% PI [0.04; 3.88]). These results highlight a nonnegligible, even high risk due to the associated consequences of such events. In alternative scenario testing, preventive anti-rabies vaccination proved to be an effective measure since removing the vaccination requirement led to a > 15-fold increase in risk. The serological testing requirement had less of an effect (approximately two-fold increase when removed) and the posttest waiting period to ensure that antibodies were not linked to an infection had a negligible effect. Any change in pet owner compliance, especially regarding vaccination, could have a major impact on the risk. This study also shows that reinforced border control staff training could be more effective in reducing risk than more frequent checks. These results provide quantitative data for assessing the probability of the rabies virus entering France, and could help policymakers decrease this risk in rabies-free areas.     

Liquidity in Asset Markets With Search Frictions

We develop a search‐theoretic model of financial intermediation in an over‐the‐counter market and study how trading frictions affect the distribution of asset holdings and standard measures of liquidity. A distinctive feature of our theory is that it allows for unrestricted asset holdings, so market participants can accommodate trading frictions by adjusting their asset positions. We show that these individual responses of asset demands constitute a fundamental feature of illiquid markets: they are a key determinant of trade volume, bid–ask spreads, and trading delays—the dimensions of market liquidity that search‐based theories seek to explain.