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     

东北亚区域经济合作与中小企业

随着区域经济一体化的迅速发展，中小企业在东北亚区域经济合作中正发挥着日益重要的作用。     

The mean-variance investment problem in a constrained financial market

This paper extends the mean-variance analysis and the two-fund separation theorem to a market with some constraints, such as, the incompleteness, prohibition of short-selling, and partial information, with stochastic interest rate, and with stochastic volatility for risky assets. By maximizing a quadratic utility of terminal wealth, we show that the efficient frontier for the problem is a straight line in the mean-standard-deviation diagram. The quadratic utility function exhibits mean-variance efficiency. Our results apply to portfolios of claims in a single period, multiperiod, and continuous time.     

中国和新加坡产业内贸易与规模经济关系的协整分析

中国和新加坡产业内贸易与规模经济存在着一种长期的均衡关系,新加坡生产企业的规模经济对产业内贸易的推动作用大于中国,中国和新加坡生产企业的规模经济与产业内贸易存在单向因果关系,即规模经济促进产业内贸易.     

A comparison of Ad valorem and per unit taxes in regulated monopolies

This paper compares the output and revenue effects in the rate-of-return regulated monopoly model. Both the ad valorem and the unit tax generally decrease the use of capital, and as such, reduce the output and raise the price. In addition, it is shown that Suits and Musgrave's conclusion of higher revenue of an ad valorem tax at a given output can apply to a regulated monopolist if the marginal product of labor under the ad valorem tax is greater than or equal to that under the unit tax. Similarly, their second conclusion, that for a given tax revenue an ad valorem tax has a larger output than a unit tax rate before the revenue-maximizing tax rate, can also apply to the regulated monopolist.     

Time to Keep Fit!

At 7 o'clock at night,Adeline Yue,who works at a foreign company in China, called it a day,packed up her bags and walked to a nearby fitness club to do her daily workout.Dancing with the music,Yue eased away the 10 hours of tired- ness and pressure of work,sweating and panting."I really enjoy coming here,to completely relax myself,and at the same time,work on a healthy body,"she said as she ran on the treadmill.     

广东本地服装品牌的市场培育

本地原创品牌的发展塑造需要坚持,也需要本地市场的支持。品牌经营者必须充分了解市场需求,有针对性地进行市场培育,同时结合自身条件进行品牌营销,才能在市场上取胜。文章基于服装品牌消费者层次分析,提出以差异性的品牌推广方式来培育忠诚顾客的若干策略,从而提升原创品牌的市场竞争力。     

面向对象程序设计教学改革与实践

指出了面向对象程序设计教学中存在的问题,针对问题提出了改革措施：采用案例式教学,加强实践教学管理,结合BB教学平台辅助教学。不断提高学生学习的自觉性和主动性,成为教学改革的重要研究内容。     

基于我国彩电企业多元化战略的实证研究

文章从实证的角度，对我国彩电企业多元化发展战略与公司绩效之间的相关性进行研究，结果显示，企业总体多元化程度与资产回报率、销售利润率和净资产回报率的相关系数为负值，即多元化程度越高的彩电企业，其公司绩效越差。针对目前我国彩电企业盲目实施多元化战略的误区，文章提出了相关对策及建议。     

政府公职人员经济人性边界界定与启示

政府公职人员是特殊经济人,并且从"经济人"角度、从历史性角度、从社会契约论角度、从初始社会分工及分工发展过程角度看,政府公职人员经济人性应有必要的边界。其经济人性发挥应符合作用空间的"非市场性"、经济人性范围的日趋"紧缩性"、经济人性目标满足渠道的"单一性"及较强的"社会性"这些内在规律。把握这些规律,可有效地建立针对政府公职人员的约束机制和非市场性的竞争机制,还可有效地促进民主发展,这对提升基本公共服务综合绩效及构建和谐社会都具有重要意义。