Recovering election winner probabilities from stock prices

Abstract After the 2020 U.S. presidential election, counting votes and calling states took more time than usual, particularly in battleground states. In the days following the election, winning probabilities changed frequently as new results were tabulated. Based on the sensitivity of stocks to changes in winning probabilities observed before the election, we show how the stock market's assessment of the unobserved post-election winning probabilities can be backed out from stock prices. Our approach is based solely on publicly available data

Applying mixed-effects growth models to back-calculated size-at-age data for Atlantic bluefin tuna (Thunnus thynnus)

We fit growth models to back-calculated size-at-age data for Atlantic bluefin tuna (Thunnus thynnus) captured in the western Atlantic management area to inform alternative growth scenarios within the current management framework of the species. The Modified-Fry function was the best-performing of three back-calculation functions based on a leave-one-out cross-validation for within-cohort comparisons. We fit multiple growth models to the back-calculated growth trajectories, and demonstrated that growth parameters were highly sensitive to whether the lack of independence between back-calculated lengths from each individual was accounted for by the model. Non-linear mixed-effects modelling provides a suitable approach for accounting for this lack of independence and the autocorrelation between back-calculated lengths from the same individual. We further demonstrated the utility of mixed-effects models for predicting future growth of individuals using a forecasting test. We used this modelling approach to demonstrate that male bluefin tuna had greater estimated asymptotic length than females, and found that there was no significant difference in growth parameters between individuals assigned to genetically distinct spawning stocks.1,58

FINAL REPORT FOR PHASE THREE OF THE ICCAT SHORT-TERM CONTRACT: SWORDFISH BIOLOGICAL SAMPLES COLLECTION FOR GROWTH, REPRODUCTION AND GENETICS STUDIES

This report details the third phase of biological sampling and associated analysis undertaken as part of an international swordfish biology program. The program was established in 2018 and sampling was conducted for swordfish in the North and South Atlantic and Mediterranean. Fish were sampled for size, sex, and maturity. Anal fin spines, otoliths, gonads, and tissues were obtained for ageing, growth, maturity and genetic analyses. These data will be used to inform ICCAT assessment and the ongoing management strategy evaluation process. In this report we examine sampling representativeness relative to spatial and temporal patterns in recent catch data. Samples were obtained from a broad temporal and spatial range, however, some improvements are required in spatial-temporal coverage.En prens

Mediterranean swordfish (Xiphias gladius Linnaeus, 1758) population structure revealed by microsatellite DNA: genetic diversity masked by population mixing in shared areas

Background The Mediterranean swordfish stock is overfished and considered not correctly managed. Elucidating the patterns of the Mediterranean swordfish population structure constitutes an essential prerequisite for effective management of this fishery resource. To date, few studies have investigated intra-Mediterranean swordfish population structure, and their conclusions are controversial. Methods A panel of 20 microsatellites DNA was used to investigate fine-scale population structuring of swordfish from six main fishing areas of the Mediterranean Sea. Results This study provides evidence to reject the hypothesis of a single swordfish population within the Mediterranean Sea. DAPC analysis revealed the presence of three genetic clusters and a high level of admixture within the Mediterranean Sea. Genetic structure was supported by significant FST values while mixing was endorsed by the heterozygosity deficit observed in sampling localities indicative of a possible Wahlund effect, by sampling admixture individuals. Overall, our tests reject the hypothesis of a single swordfish population within the Mediterranean Sea. Homing towards the Mediterranean breeding areas may have generated a weak degree of genetic differentiation between populations even at the intra-basin scale

Timing of Increment Formation in Atlantic Bluefin Tuna (Thunnus thynnus) Otoliths.

Controversies remain regarding the periodicity, or seasonality, of otolith growth band formation, which directly influences a correct age determination of Atlantic bluefin tuna using this structure. The aim of this work was to apply marginal increment analysis and marginal edge analysis to determine the timing of band deposition. The index of completion was analyzed using general additive models to evaluate the importance of variables, such as month, age/size, and reader. Results indicate that the opaque band formation begins in June and is completed by the end of November. From the end of the year to the beginning of the following year, there is minimal marginal edge growth as the translucent band begins to form. The translucent zone then reaches a maximum development in May. The results obtained in this study provide evidence that the annulus formation in the otoliths of Atlantic bluefin tuna are completed later in the calendar year than previously thought. This would mean it is necessary to delay the date of the current July 1st adjustment criterion to November 30

Terms of reference for ECOCARD intersessional work

We recommend that a sub-group is formed to work and discuss intersessionally on the applicability and functionality of the Ecosystem Report Card (EcoCard) as a tool for monitoring the impacts of ICCAT fisheries and contribute to the progress of implementing Ecosystem-Based Fisheries Management (EBFM) in ICCAT. To do so, the sub-group will be tasked to (1) review data availability and ICCAT management framework to inform the development of EcoCard, (2) summarize in a guideline document the history and current state of the EcoCard developments in ICCAT, (3) seek feedback and synergies with other relevant work and processes across all species groups and sub-committees of the SCRS, and (4) make recommendations for improvements to make the EcoCard more functional and adaptable to end-user needs. A more functional EcoCard has the potential to (a) communicate more effectively the use of this tool to the wider ICCAT community including its main objective and purpose, (b) attract more research and participation for its development and create more synergies of the work across all species groups and subcommittees of the SCRS, and (c) identify research priorities as well as relevant gaps which will allow management planning and identification of priorities by the ICCAT Commission.Nous recommandons la création d'un sous-groupe chargé de travailler et de discuter, entre les sessions, de l'applicabilité et de la fonctionnalité de la fiche informative sur les écosystèmes (EcoCard) en tant qu'outil de suivi des impacts des pêcheries de l'ICCAT et de contribuer aux progrès de la mise en œuvre de la gestion des pêcheries basée sur l’écosystème (EBFM) au sein de l'ICCAT. Pour ce faire, le sous-groupe sera chargé (1) d'examiner la disponibilité des données et le cadre de gestion de l'ICCAT afin de renseigner le développement de l'EcoCard, (2) de résumer dans un document d'orientation l'historique et l'état actuel des développements de l’EcoCard au sein de l'ICCAT, (3) de rechercher un retour d'information et des synergies avec d'autres travaux et processus pertinents dans tous les groupes d'espèces et sous-comités du SCRS, et (4) de faire des recommandations d'améliorations pour rendre l’EcoCard plus fonctionnelle et adaptable aux besoins des utilisateurs finaux. Une EcoCard plus fonctionnelle a le potentiel de (a) communiquer plus efficacement l'utilisation de cet outil à l'ensemble de la communauté de l'ICCAT, y compris son objectif et son but principaux, (b) attirer davantage de recherche et de participation pour son développement et créer davantage de synergies de travail entre tous les groupes d'espèces et les sous-comités du SCRS, et (c) identifier les priorités de recherche ainsi que les lacunes pertinentes qui permettront la planification de la gestion et l'identification des priorités par la Commission de l'ICCAT.Recomendamos que se forme un subgrupo para trabajar y discutir en el periodo intersesiones la aplicabilidad y funcionalidad de la ficha informativa sobre ecosistemas (EcoCard) como herramienta para hacer un seguimiento del impacto de las pesquerías de ICCAT y contribuir al progreso de la implementación de la Ordenación pesquera basada en el ecosistema (EBFM) en ICCAT. Para hacerlo, el subgrupo se encargará de: (1) revisar la disponibilidad de datos y el marco de ordenación de ICCAT para aportar información al desarrollo de la EcoCard, (2) resumir en unas directrices la historia y el estado actual del desarrollo de la EcoCard en ICCAT, (3) buscar retroalimentación y sinergias con otros trabajos y procesos pertinentes en todos los grupos de especies y subcomités del SCRS y (4) hacer recomendaciones para mejorar la EcoCard y hacerla más funcional y adaptable a las necesidades del usuario final. Una EcoCard más funcional tiene el potencial de (a) comunicar de forma más eficaz el uso de esta herramienta a la comunidad de ICCAT, incluidos su principal objetivo y propósito, (b) atraer más investigaciones y participación para su desarrollo y crear más sinergias del trabajo en todos los grupos de especies y subcomités del SCRS y (c) identificar prioridades de investigación, así como lagunas importantes que permitirán planificar la ordenación y la identificación de prioridades por parte de la Comisión.Versión del edito