Influence diagnostics in the capital asset pricing model under elliptical distributions

In this paper we consider the Capital Asset Pricing Model under Elliptical (symmetric) Distributions. This class of distributions, which contains the normal distribution, t, contaminated normal and power exponential, among others, offers a more flexible framework for modelling asset prices or returns. In order to analyze the sensibility to possible outliers and/or atypical returns of the maximum likelihood estimators, the local influence method was implemented. The results are illustrated by using a set of shares from companies who trade in the Chilean Stock Market. Our main conclusion is that symmetric distributions having heavier tails than those of the normal distribution, especially the t distribution with small degrees of freedom, show a better fit and allow the reduction of the influence of atypical returns in the maximum likelihood estimators.     

老年急性白血病治疗方案的临床研究

目的研究治疗老年急性白血病的最佳策略,提高老年急性白血病患者完全缓解(CR)率,改善老年急性白血病患者的生活质量。方法回顾性分析35例老年急性白血病的临床表现,实验室检查特征及不同化疗方案的疗效。结果:联合化疗17例,CR率47%(8/17),其中急性非淋巴细胞性白血病(ANLL)9例,CR率44.4%(4/9);急性淋巴细胞性白血病(ALL)8例,CR率50%(4/8)。小剂量阿糖胞苷(Ara-C)或三尖杉脂碱(H)化疗9例,CR率22.2%(2/9)。全反式维甲酸(ATRA)治疗3例,1例安全缓解。姑息治疗6例。结论临床上老年急性白血病普遍对化疗反应差,CR率低。对老年急性白血病应选择积极、合理、个体化的治疗方案,有利于提高老年急性白血病的疗效,改善老年急性白血病患者的生活质量。     

Educational responses to immigrant students in Madrid

During the last few years, changes in the Spanish educational system have had a far reaching impact. Several factors have been critical: (1) the progressive decentralization of education by the government, now a responsibility of regional governments; (2) the extension of compulsory education to the age of 16; and finally (3) the increase in the number of immigrant students, which has significantly added to the existing cultural diversity. The enrolment of immigrant students in Spanish schools is a relatively recent phenomenon (starting 15 years ago) when compared with other European countries. Madrid is the region in Spain with the largest number of students. As most of these students were born outside of Spain, we cannot yet speak of a second generation. The research described here investigated how the educational system in Madrid confronted the challenge of an increasing number of immigrant students. The institutional response was the Madrid Regional Government’s Compensatory Education Regional Plan. This encompasses several measures, which are described here. After a critical analysis of educational policies pertaining to immigrant pupils, the paper suggests ways of overcoming a purely compensatory approach. Intercultural education plays a key role is such considerations.     

Semiparametric Bayesian classification with longitudinal markers

Summary.  We analyse data from a study involving 173 pregnant women. The data are observed values of the β human chorionic gonadotropin hormone measured during the first 80 days of gestational age, including from one up to six longitudinal responses for each woman. The main objective in this study is to predict normal versus abnormal pregnancy outcomes from data that are available at the early stages of pregnancy. We achieve the desired classification with a semiparametric hierarchical model. Specifically, we consider a Dirichlet process mixture prior for the distribution of the random effects in each group. The unknown random-effects distributions are allowed to vary across groups but are made dependent by using a design vector to select different features of a single underlying random probability measure. The resulting model is an extension of the dependent Dirichlet process model, with an additional probability model for group classification. The model is shown to perform better than an alternative model which is based on independent Dirichlet processes for the groups. Relevant posterior distributions are summarized by using Markov chain Monte Carlo methods.     

Describing poverty in an ultraperipheral region: The case of the Canary Islands

Based on data from the Survey on Social Conditions in the Canary Islands of the Instituto Canario de Estadística, this study analyzes poverty in Canary households by island of residence, age, employment and the educational level of the main provider. In addition to accepted objective measures, we also estimate poverty using subjective methods, in which the poverty line is defined or obtained by the opinion of household members of their own level of poverty.     

FROM MAIZE TO HAZE: AGRICULTURAL SHOCKS AND THE GROWTH OF THE MEXICAN DRUG SECTOR

Understanding how economic incentives affect illegal drug production is essential for crafting policies in response to the international drug trade. Policymakers typically face a choice between two strategies: targeting criminal groups via law enforcement, and offering producers incentives to engage in alternate activities. Yet, little is known about how the returns to alternate legal activities affect drug supply. We contribute to this literature by examining how shocks to legal commodity prices affect the drug trade in Mexico. Our analysis exploits exogenous movements in the Mexican maize price stemming from weather conditions in US maize‐growing regions, as well as exports of other major maize producers. Using data on over 2200 municipios spanning 1990–2010, we show that lower prices differentially increased the cultivation of both marijuana and opium poppies in municipios more climatically suited to growing maize. We also find impacts on downstream drug‐trade outcomes, including drug cartel operations and killings perpetrated by these groups. Our findings demonstrate that maize price changes contributed to the burgeoning drug trade in Mexico, and point to the violent consequences of an expanding drug sector.     

The Immigrant Paradox in Pregnancy: Explaining the First‐Generation Advantage for Latina Adolescents

The immigrant paradox is a population health pattern whereby later generation immigrant youth display less favorable outcomes when compared to first‐generation co‐ethnic peers. This study examines the role of number of sex partners in explaining the immigrant paradox in pregnancy among Latina adolescents. This secondary analysis utilized a nationally representative sample of Latinas in the National Longitudinal Study of Adolescent Health. As expected, first‐generation Latina adolescents demonstrated less risk than second‐ or third+ generation Latinas for becoming pregnant. Further, the lower number of sexual partners fully accounted for the first generation's advantage in lower rate of adolescent pregnancy. These findings have important implications for healthcare providers who work with Latina girls in pregnancy prevention.     

The Influence of Gender Equality on Volunteering Among European Senior Citizens

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - This research analyzes how gender equality influences the participation of European senior citizens in a range of...