6 resultados para duration analysis
em Universidad del Rosario, Colombia
Resumo:
The growing empirical literature on the analysis of civil war has recently included the study of conflict duration at the cross-country level. This paper presents, for the first time, a within-country analysis of the determinants of violence duration. I focus on the experience of the Colombian armed conflict. While the conflict has been active for about five decades, local violence ebbs and flows and areas experiencing continuous conflict coexist with places that have been able to resile and where violence is mostly absent. I examine a wide range of factors potentially associated with violence duration at the municipal level, including scale variables, geographical conditions, economic and social variables, institutions and state presence, inequality, government intervention, and victimization variables. I characterize a few variables robustly correlated with the persistence of localized conflict, both across specifications and using different econometric models of duration analysis.
Resumo:
Recent empirical work emphasizes the importance of the extensive margin of trade (new exporters, new export activities) for long run export growth. In this context, understanding the determinants of duration of new exporters is key for underpinning the dynamics of exports growth. As new exporters tend to show low survival rates, identifying the determinants of export duration is highly relevant for academic and policy purposes. In this paper, we explore whether information externalities arising from different levels of spatial interaction allow new exporters to increase the duration of their trade activities. For this, we use transaction level data on Colombian exports between 2004 and 2011. Results show that export networks, understood as the agglomeration of exporting firms at different spatial levels, reduce the risk of dropping out from exporting and that this effect is stronger the more similar are export activities carried out by firms
Resumo:
This study proposes a new method for testing for the presence of momentum in nominal exchange rates, using a probabilistic approach. We illustrate our methodology estimating a binary response model using information on local currency / US dollar exchange rates of eight emerging economies. After controlling for important variables a§ecting the behavior of exchange rates in the short-run, we show evidence of exchange rate inertia; in other words, we Önd that exchange rate momentum is a common feature in this group of emerging economies, and thus foreign exchange traders participating in these markets are able to make excess returns by following technical analysis strategies. We Önd that the presence of momentum is asymmetric, being stronger in moments of currency depreciation than of appreciation. This behavior may be associated with central bank intervention
Resumo:
Objectives: to evaluate the efficacy and safety of human immunoglobulin versus plasmapheresis in the management of autoimmune neurologic diseases. Likewise, length of hospital stay and duration of ventilator support were compared. Methods: Randomized controlled trials and analytical observational studies of more than 10 cases, were reviewed. Cochrane Neuromuscular Disease Group trials, MEDLINE, EMBASE, HINARI Ovid, the Database of abstracts of reviews of effectiveness and the Economic evaluation Database were searched as data source. Reference lists were examined for further relevant articles. A random-effect model was used to derive a pooled risk ratio. Results: 725 articles were found and 27 met the criteria for a population studied of 4717 cases: 14 articles were about Guillain Barré syndrome, 10 of Myasthenia Gravis, one of Sydenham Chorea, one of Chronic inflammatory demyelinating polyneuropathy, and one of PANDAS. No evidence was found in favor of any of the two treatments as regards effectiveness (OR 0.94, IC 0.63 – 1.41, p= 0.77) or ventilator support time; IGIV had a significant better safety profile than plasmapheresis (OR 0.70, IC 0.51 – 0.96, p= 0.03) and patients needed less time of hospital stay (p=0.03). Conclusions: There is no evidence for superiority in the effectiveness of immunoglobulin or plasmapheresis in the management of autoimmune neurologic diseases. Nevertheless, patients treated with immunoglobulin have statistically significant less adverse effects, a shorter hospital stay and a tendency of less ventilator support time. These premises could lead to fewer costs for health services but an economic study should be done.
Resumo:
Purpose: there are many studies reporting the benefits of pulmonary rehabilitation, but few of them exhibit the behavior and activities of these services. This article presents the characteristics of services, parts management and training level of team members, in addition to the variables or instruments used to measure the effectiveness and impact in these programs. Method: it was made a cross sectional convenience sample which included seven pulmonary rehabilitation services in four Colombian cities (Bogotá, Medellín, Manizales and Cali), selected by the coverage, for having at least one year of experience and for being formally established and recognized nationwide. The interdisciplinary team of each service answered a survey that was validated through a pilot test and expert consensus. Participation was voluntary. Results: labor onset pulmonary rehabilitation services correspond to an average of a decade, with COPD and asthma pathologies of attention. The programs are characterized by an outpatient treatment with an average duration of eight to twelve weeks, with a frequency of an hour three times a week. Also, the director of the service is regularly a pulmonologist and the coordinator a physiotherapist (57.14%). The posgradual training of these professionals is notable, and they report to have procedural, administrative and communicative skills, but qualify regular there research skills. The physical and technological resources are well tested. 71.42% have done impact studies, but only 28.57% have been published. All have in common training in upper limbs, lower limbs, respiratory muscles, counseling, functional assessment and quality of life. The effectiveness and impact of programs is measured by the walking test, quality of life questionnaires and activities of daily living.
Resumo:
Los métodos disponibles para realizar análisis de descomposición que se pueden aplicar cuando los datos son completamente observados, no son válidos cuando la variable de interés es censurada. Esto puede explicar la escasez de este tipo de ejercicios considerando variables de duración, las cuales se observan usualmente bajo censura. Este documento propone un método del tipo Oaxaca-Blinder para descomponer diferencias en la media en el contexto de datos censurados. La validez de dicho método radica en la identificación y estimación de la distribución conjunta de la variable de duración y un conjunto de covariables. Adicionalmente, se propone un método más general que permite descomponer otros funcionales de interés como la mediana o el coeficiente de Gini, el cual se basa en la especificación de la función de distribución condicional de la variable de duración dado un conjunto de covariables. Con el fin de evaluar el desempeño de dichos métodos, se realizan experimentos tipo Monte Carlo. Finalmente, los métodos propuestos son aplicados para analizar las brechas de género en diferentes características de la duración del desempleo en España, tales como la duración media, la probabilidad de ser desempleado de largo plazo y el coeficiente de Gini. Los resultados obtenidos permiten concluir que los factores diferentes a las características observables, tales como capital humano o estructura del hogar, juegan un papel primordial para explicar dichas brechas.