Aplicaciones de la teorıa de juegos a los problemas de reparto

Se abordan distintos problemas de reparto utilizando la teoría de juegos cooperativos de utilidad transferible a través de distintas aplicaciones como son el problema de repartir el coste de construcción de un aeropuerto, el problema del reparto de costes de transacción en una red de cajeros automáticos, el problema de repartir el coste de ejecución de una ruta, prestando un determinado servicio, entre los usuarios de dicho servicio o el problema de repartir beneficios cuando varios agentes cooperan juntando sus recursos y compartiendo sus tecnologías de producción. También se analiza la naturaleza multidimensional de alguno de estos problemas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Mortality of emergency abdominal surgery in high-, middle- and low-income countries

Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low- or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI). Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression. Results: Data were obtained for 10 745 patients from 357 centres in 58 countries; 6538 were from high-, 2889 from middle- and 1318 from low-HDI settings. The overall mortality rate was 1⋅6 per cent at 24 h (high 1⋅1 per cent, middle 1⋅9 per cent, low 3⋅4 per cent; P < 0⋅001), increasing to 5⋅4 per cent by 30 days (high 4⋅5 per cent, middle 6⋅0 per cent, low 8⋅6 per cent; P < 0⋅001). Of the 578 patients who died, 404 (69⋅9 per cent) did so between 24 h and 30 days following surgery (high 74⋅2 per cent, middle 68⋅8 per cent, low 60⋅5 per cent). After adjustment, 30-day mortality remained higher in middle-income (odds ratio (OR) 2⋅78, 95 per cent c.i. 1⋅84 to 4⋅20) and low-income (OR 2⋅97, 1⋅84 to 4⋅81) countries. Surgical safety checklist use was less frequent in low- and middle-income countries, but when used was associated with reduced mortality at 30 days. Conclusion: Mortality is three times higher in low- compared with high-HDI countries even when adjusted for prognostic factors. Patient safety factors may have an important role. Registration number: NCT02179112 (http://www.clinicaltrials.gov)

Construcción de índices ponderados multicriterio con información ordinal

El objetivo de este trabajo es establecer una metodología que permita construir índices para la evaluación de un conjunto de unidades, cuando se dispone de las valoraciones de éstas con respecto a varios criterios medidos en una escala ordinal. Con objeto de reflejar lo más fielmente posible los aspectos evaluados, en los índices compuestos que proponemos se incorpora la información disponible sobre la importancia relativa de los distintos criterios y sobre la importancia de las distintas categorías ordinales. Se ilustra el procedimiento con un análisis de valoraciones realizadas por los alumnos de las distintas Titulaciones de la Universidad Pablo de Olavide de Sevilla

Soluciones Estables en Juegos Cooperativos bajo Incertidumbre.

Multiple scenario cooperative games model situations where the worth of the coalitions is valued in several scenarios simultaneously or under di erent states of nature. We focus on the identification of those allocations which are stable in the sense that agents have no incentives to abandon the group. The stability of an allocation depends on how the quantities the coalitions obtain are compared with the vector-valued worth of the coalition, therefore, diferent extensions of the notion of core emerge, depending on how these comparisons are made. We introduce the new notions of weighting cores and analize the relationships between them and the existing core solutions. We also address the inclusion in the model of partial information about the probabilities of occurrence of the scenarios. In order to identify allocations which are also stable in the presence of probability information, we extend the notions of core to this new setting, and provide results which permit the efective calculation of the corresponding sets of allocations.Los juegos cooperativos con múltiples escenarios modelan situaciones de decisión bajo incertidumbre, cuando se tiene que repartir un bien entre un conjunto de individuos, teniendo en cuenta los valores de las coaliciones bajo diferentes escenarios simultáneamente o bajo diferentes estados de la naturaleza. En este trabajo se proponen y analizan diferentes conceptos de solución para este tipo de juegos y se proporcionan procedimientos para calcular los repartos que generan. En particular, se introducen los núcleos de ponderación como solución y se analizan las relaciones entre éstos y los conceptos existentes en la literatura: núcleo de preferencia y núcleo de dominancia. A continuación, se considera la posibilidad de incorporar información parcial sobre las probabilidades de ocurrencia de los distintos escenarios con objeto de obtener conjuntos de repartos que sean estables cuando se dispone de información probabilitica. Para ello se presentan nuevos conceptos de núcleo con información parcial que extienden las nociones de nucleo de preferencia y nucleo de dominancia. Se investigan las relaciones entre ellos y se proporciona el procedimiento para el cálculo de los resultados que generan

Problema de bancarrota global con preferencias maxmin

Analizamos problemas de reparto de múltiples bienes en los que los agentes tienen preferencias del tipo maxmin sobre los resultados que obtienen con respecto a los diferentes bienes. En este contexto introducimos el concepto de eficiencia maxmin, y definimos una propiedad de estabilidad para asignaciones globales que es más exigente que la eficiencia maxmin y se apoya en un juego de utilidad transferible que también analizamos. Finalmente proponemos un procedimiento para obtener el conjunto de asignaciones globales que son estables.We address multiple issue division problems where the agents exhibit maxmin preferences on the results they obtain with respect to the different issues are addressed. The concept of max-min efficiency is introduced in this context, and a property of stability for global allocations which is more demanding than maxmin efficiency and is supported by a transferable utility game is analyzed. Finally, we propose a procedure to obtain the set of global allocations which exhibit the condition of stability

Problema de bancarrota global con preferencias maxmin

Analizamos problemas de reparto de múltiples bienes en los que los agentes tienen preferencias del tipo maxmin sobre los resultados que obtienen con respecto a los diferentes bienes. En este contexto introducimos el concepto de eficiencia maxmin, y definimos una propiedad de estabilidad para asignaciones globales que es más exigente que la eficiencia maxmin y se apoya en un juego de utilidad transferible que también analizamos. Finalmente proponemos un procedimiento para obtener el conjunto de asignaciones globales que son estables.We address multiple issue division problems where the agents exhibit maxmin preferences on the results they obtain with respect to the different issues are addressed. The concept of max-min efficiency is introduced in this context, and a property of stability for global allocations which is more demanding than maxmin efficiency and is supported by a transferable utility game is analyzed. Finally, we propose a procedure to obtain the set of global allocations which exhibit the condition of stability

Un algoritmo para el cálculo de asignaciones en el problema de división con referencias múltiples.

In this paper we consider an extension of the classic division problem with claims, the division problem with multiple references. For this problem, we have designed a Talmudic rule that takes into account the multidimensionality of the agents' references. We propose an algorithm to compute the allocations induced by the rule and present computational results.En este trabajo consideramos el problema de reparto con referencias múltiples. Como solución para este problema, hemos diseñado una regla que extiende la conocida regla del Talmud y tiene en cuenta la multidimensionalidad de las referencias de cada agente. Proponemos un algoritmo para el cálculo de las asignaciones que proporciona la regla y presentamos resultados computacionales

Reglas leximin para problemas de bancarrota con incertidumbre*

We model bankruptcy problems under uncertainty under the assumption that there are several possible states of nature, each of which is identified with a di®er-ent bankruptcy problem. For this multi-dimensional extension of classic bankruptcy problems, we consider situations in which agents exhibit at the same time additive preferences and leximin preferences on their possible results. We propose division rules which combine di®erent rationality principles and guarantee eÿciency with respect to leximin preferences.En este trabajo modelizamos los problemas de bancarrota en condiciones de in-certidumbre, bajo el supuesto de que hay varios posibles estados de la naturaleza, identificándose cada uno de ellos con un problema de bancarrota diferente. Para esta extensión multidimensional de los problemas clásicos de bancarrota, consideramos situaciones en las que los agentes presentan preferencias de tipo aditivo y leximin sobre los posibles resultados. Proponemos reglas de reparto en las que se combinan diferentes principios de racionalidad y se garantiza la eficiencia con respecto a las preferencias de tipo leximin