Improved estimation of portfolio value‐at‐risk under copula models with mixed marginals

Portfolio value‐at‐risk (PVAR) is widely used in practice, but recent criticisms have focused on risks arising from biased PVAR estimates due to model specification errors and other problems. The PVAR estimation method proposed in this article combines generalized Pareto distribution tails with the empirical density function to model the marginal distributions for each asset in the portfolio, and a copula model is used to form a joint distribution from the fitted marginals. The copula–mixed distribution (CMX) approach converges in probability to the true marginal return distribution but is based on weaker assumptions that may be appropriate for the returns data found in practice. CMX is used to estimate the joint distribution of log returns for the Taiwan Stock Exchange (TSE) index and the associated futures contracts on SGX and TAIFEX. The PVAR estimates for various hedge portfolios are computed from the fitted CMX model, and backtesting diagnostics indicate that CMX outperforms the alternative PVAR estimators. © 2006 Wiley Periodicals, Inc. Jrl Fut Mark 26:997–1018, 2006     

物流网站中的虚假宣传与信号传递

指出部分物流网站存在虚假宣传的基础上，构建了物流服务信号传递分析模型，阐述了量化的服务承诺是有效的信号显示的观点，提出了物流企业服务承诺的制定原则。     

文化学研究视角下的唐代小说集《纪闻》

研究唐代小说的视角众多，从文化学角度将小说和时代文化结合起来是其中一种。唐前期小说集《纪闻》中蕴涵着丰富的文化信息。通过阅读《纪闻》小说文本，进一步探讨作品中所反映出的唐代宗教及民间信仰、女性生存状况、中外交流情况等。     

冬日同游世界温泉王国

温泉是秋冬的热门话题,气温越低人们对于温泉的向往就越热烈。远在北极的冰岛蓝湖,新西兰神秘的魔戒之泉罗托鲁瓦,以及瑞士最纯净的日内瓦湖区的温泉,还有印尼热腾腾的火山温泉。也许你对它们其中之一已经很熟悉,早已心中酝酿多时,那么怀着对它们的向往去吧,不要错过这美好时节!     

晶化时间对CoAPO-11分子筛合成过程中转晶的影响

本文研究了晶化时间对低钴含量(x=0.1)的CoAPO-11分子筛合成过程中转晶现象的影响,并采用XRD、SEM对产物进行表征。结果表明,200℃下晶化48 h,可获得纯相CoAPO-11;当晶化时间超过48 h时,产物便开始向[Co-Al-P-O]-GIS型分子筛转化;晶化延长至72 h时,产物已全部转化为[Co-Al-P-O]-GIS型分子筛,该转化过程不可逆。从分子筛骨架结构单元出发,阐述了转晶现象的内在影响因素。     

改革开放以来广州经济增长因素分析

本文从实证角度建立计量模型,利用主成分分析方法和最小二乘回归的方法,对广州改革开放30多年以来的经济增长因素进行了具体分析,研究表明改革开放30多年来,广州经济增长的促进因素主要是劳动力数量的增长,经济制度的变革,产业结构的升级,以及人力资本增长的作用,物质资本不是促进广州经济增长的主要因素。     

中国货币政策紧缩 到底有多紧？

[英国路透社3月18日]中国反复重申，转向“紧缩”货币政策，取代之前“适度从紧”政策，以抑制创下10年新高的通货膨胀。     

后现代主义视野中的《白雪公主》

美国后现代主义作家唐纳德·巴塞尔姆在他的代表作<白雪公主>中成功地运用后现代主义创作手法即碎片式的拼贴、游戏式的戏仿和喜剧性的反讽彻底颠覆了经典的童话故事<白雪公主>,淋漓尽致地嘲讽了后现代社会平庸无聊的生活和精神的空虚与困惑,从而深刻揭示了后现代社会生活的反童话本质.     

Financial Development and Economic Growth: Empirical Evidence from Six MENA Countries

This paper examines the causal relationship between financial development and economic growth for six Middle Eastern and North African countries (Algeria, Egypt, Israel, Morocco, Syria, and Tunisia), within a quadvariate vector autoregressive framework. We employ four different measures of financial development and apply the augmented vector autoregression vector (VAR) methodology of Toda and Yamamoto to test for Granger causality. Our empirical results strongly support the hypothesis that finance leads to growth in five out of the six countries. Only in Israel could weak support be found for causality running from economic growth to financial development but no causality in the other direction. These findings suggest the need to accelerate the financial reforms that have been launched since the mid 1980s and to improve the efficiency of these countries’ financial systems to stimulate saving/investment and, consequently, long‐term economic growth.     

为什么国有企业越来越垄断?

近年来,我国的国有企业在产业政策的保护下表现出越来越垄断的趋势。本文运用共同代理模型解释了这种政策倾向的形成原因。代表各个产业部门的利益集团围绕政府的政策展开博弈,政策的形成是政府对各个产业利益集团进行平衡的结果。但是,政府对国有部门的重视程度超过非国有部门。随着国有企业逐渐从许多产业退出,余下的国有部门越来越缺乏其他利益集团的制约,政府因而就倾向于保护这些国有部门的垄断利益。