EMPIRICAL PERFORMANCE OF GARCH MODELS WITH HEAVY‐TAILED INNOVATIONS

We introduce a new type of heavy‐tailed distribution, the normal reciprocal inverse Gaussian distribution (NRIG), to the GARCH and Glosten‐Jagannathan‐Runkle (1993) GARCH models, and compare its empirical performance with two other popular types of heavy‐tailed distribution, the Student's t distribution and the normal inverse Gaussian distribution (NIG), using a variety of asset return series. Our results illustrate that there is no overwhelmingly dominant distribution in fitting the data under the GARCH framework, although the NRIG distribution performs slightly better than the other two types of distribution. For market indexes series, it is important to introduce both GJR‐terms and the NRIG distribution to improve the models’ performance, but it is ambiguous for individual stock prices series. Our results also show the GJR‐GARCH NRIG model has practical advantages in quantitative risk management. Finally, the convergence of numerical solutions in maximum‐likelihood estimation of GARCH and GJR‐GARCH models with the three types of heavy‐tailed distribution is investigated.     

服务营销:3G时代企业致胜的法宝

随着3G时代的到来,电信企业之间的竞争将更加激烈.电信企业要想在激烈的竞争环境中立足,拥有自己的市场,必须以服务营销为战略研究重点,建立以用户为中心的服务营销体制,建立包括企业利润、企业的成长性,用户忠诚、用户满意、提供给用户的产品与服务的价值,员工能力、满意、忠诚及效率在内的电信服务利润链.     

民族地区民营经济发展与地区经济态势相关性分析

改革开放后,我国民族地区的经济发展取得了巨大成就,但民族地区经济发展与全国的发展差距却没有明显缩小。本文将民族地区经济发展与其民营经济发展状况进行相关性分析,发现二者之间呈现出较强的相关性,所以要加快民族地区经济发展速度必须促进民族地区民营经济的发展。     

建立计算机管理系统 提高机车检修质量

山海关机务段针对传统质量管理手段和机车检修方法存在管理方法落后、检测手段落后和考核机制滞后等弊端,建立机车检修质量计算机管理系统。该系统具有收集处理检修质量信息,提供质量分析、定责、考核依据,强化配件检修质量及检修质量控制等功能,促进了机车质量稳步提高,为旅客列车安全正点运行提供了有力保障,为运输畅通和增运增收发挥了重要作用。     

迷上酒吧的理由

有人比喻酒吧是水泥城市的天窗，“人们迫不及待地探出头，试图逃脱逼仄的空间，哪怕得到片刻的欢娱。”而在成都，在迷上——一个酒吧，富有想象力的名字将欢娱变成了前戏：人们夜夜笙歌，长久缠绵悱恻。[编者按]     

贯彻钢铁产业政策走科学发展之路

时光荏苒，钢铁行业不知不觉又沐浴在2006年的春光之中。从2004年以来国家陆续出台宏观调控政策，到2006年年初的平衡过渡，钢铁行业跨越了由风声鹤唳到有惊无险的历程。     

Continuous extension of preferences

We consider the problem of extending preferences from a subset of a commodity space to the entire space. It is a simple consequence of the Tietze extension theorem that continuous preferences can be extended if they are defined on closed subsets of a normal space and are representable by utility functions. We show the following: If the space is a non-separable metric space, then extension of preferences is not always possible. In fact for (path-connected) metric spaces, extension property, utility representation property, and separability are equivalent to each other.