Bias Correction in the Dynamic Panel Data Model with a Nonscalar Disturbance Covariance Matrix

Approximation formulae are developed for the bias of ordinary and generalized Least Squares Dummy Variable (LSDV) estimators in dynamic panel data models. Results from Kiviet [Kiviet, J. F. (1995), on bias, inconsistency, and efficiency of various estimators in dynamic panel data models, J. Econometrics68:53-78; Kiviet, J. F. (1999), Expectations of expansions for estimators in a dynamic panel data model: some results for weakly exogenous regressors, In: Hsiao, C., Lahiri, K., Lee, L-F., Pesaran, M. H., eds., Analysis of Panels and Limited Dependent Variables, Cambridge: Cambridge University Press, pp. 199-225] are extended to higher-order dynamic panel data models with general covariance structure. The focus is on estimation of both short- and long-run coefficients. The results show that proper modelling of the disturbance covariance structure is indispensable. The bias approximations are used to construct bias corrected estimators which are then applied to quarterly data from 14 European Union countries. Money demand functions for M1, M2 and M3 are estimated for the EU area as a whole for the period 1991: I-1995: IV. Significant spillovers between countries are found reflecting the dependence of domestic money demand on foreign developments. The empirical results show that in general plausible long-run effects are obtained by the bias corrected estimators. Moreover, finite sample bias, although of moderate magnitude, is present underlining the importance of more refined estimation techniques. Also the efficiency gains by exploiting the heteroscedasticity and cross-correlation patterns between countries are sometimes considerable.     

文化差异给英汉翻译带来的困难

翻译涉及到语言和文化。本文从五个方面阐述了不同的文化观念给翻译带来的困难,并以举例的方式提出了解决这些困难的方法。     

被遮蔽的"文革"叙事--从《玫瑰门》评论小史谈起

<玫瑰门>是铁凝20世纪80年代后期一部以"文革"为背景的重要作品,但从<玫瑰门>的评论小史可以看到,80年代后半期以来,评论界对"文革"主题的忽略与遮蔽是普遍的.其中对抽象人性的偏爱,导致评论界对铁凝等一些小说家揭开"文革"政治对人性阴暗面的催生和放大,与人性固有之丑陋的合谋真相这一努力,大多视而不见.这一情形与80年代中期开始形成的当代文学观密不可分,也与"瞻前"而非"顾后"的社会文化心理有着内在的联系.     

RuCl2[P(C6H5)3]2(NH2CH2CH2NH2)催化苯乙酮加氢反应的研究

优化了以RuCl2[P(C6H5)3]2(NH2CH2CH2NH2)作催化剂催化苯乙酮加氢制备α-苯乙醇的反应条件,考察了反应温度、反应压力、碱的用量及不同的碱对反应的影响,得出了一个较好的反应条件.     

Generalized quasi-likelihood

The quasi-score function, as defined by Wedderburn (1974) and McCullagh (1983) and so on, is a linear function of observations. The generalized quasi-score function introduced in this paper is a linear function of some unbiased basis functions, where the unbiased basis functions may be some linear functions of the observations or not, and can be easily constructed by the meaning of the parameters such as mean and median and so on. The generalized quasi-likelihood estimate obtained by such a generalized quasi-score function is consistent and has an asymptotically normal distribution. As a result, the optimum generalized quasi-score is obtained and a method to construct the optimum unbiased basis function is introduced. In order to construct the potential function, a conservative generalized estimating function is defined. By conservative, a potential function for the projected score has many properties of a log-likelihood function. Finally, some examples are given to illustrate the theoretical results. This paper is supported by NNSF project (10371059) of China and Youth Teacher Foundation of Nankai University.     

从国际法看巴勒斯坦建国

巴勒斯坦建国问题是巴以冲突中悬而未决的棘手问题，在当前巴以和平进程受挫情况下，它渐渐成为巴以和谈的重要议题，且有可能成为和谈的突破口．本文从国际法角度，结合历史，分析了巴建国问题在法理上具备了哪些条件，缺哪些条件，据此对巴建国前景作个预测．     

Sifting the wheat from the chaff—the organization of telephone intake and the selection of social assistance inquirers in Sweden

In Sweden, the initial contact between help-seeking people and a social welfare office normally takes place over the telephone, with designated intake officers handling those aiming to apply for social assistance. Citizens seeking help are here sorted according to various eligibility criteria as well as according to different intake routines. The outcome of the sorting process is that some receive an appointment for a further assessment while others are sent away. This article describes and classifies the degree of selection at seven telephone intakes, discusses relations between the degrees of selection and reasons for selection and distinguishes several selection strategies.     

Statistik für bivariate gemischte Poisson–Prozesse am Beispiel der Kraftfahrthaftpflichtversicherung

Zusammenfassung: In diesem Artikel wird der Weg von einem univariaten gemischten Poisson–Prozess, der in vielen Bereichen zum Z?hlen von Ereignissen benutzt wird, zu einem bivariaten gemischten Poisson–Prozess aufgezeigt. Dazu werden einige Eigenschaften des bivariaten Prozesses angegeben. Im zweiten Teil der Arbeit wird gezeigt, wie mit Hilfe dieses Prozesses der übergang von einem herk?mmlichen Bonus–Malus–System in der Kraftfahrthaftpflichtversicherung zu einem Bonus–Malus–System mit Berücksichtigung der Schadenart beschritten werden kann. Dazu wird zuerst eine Modellprüfung der gegebenen Daten vorgenommen und sodann werden für verschiedene mischende Verteilungen die Verteilungsparameter gesch?tzt und Nettopr?mien angegeben sowie die Prognosegenauigkeit getestet.

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Summary: In this paper we show that the model of the bivariate mixed Poisson process arises in a natural way from the univariate mixed Poisson process, which is used in several areas for counting certain events. Furthermore we state some properties of the bivariate process. In the second part of the paper we illustrate how by means of the bivariate mixed Poisson process a bonus–malus system handling different types of accidents can be derived from the classical bonus–malus system in third–party liability insurance. To this end we first check the model on the given data and then estimate distribution parameters and compute net premiums for different mixing distributions as well as test the prediction probabilities.

* Vortrag am Dresdner Forum zur Versicherungsmathematik: Tarifierung in Erst- und Rückversicherung am 25. Juni 2004. Für die Unterstützung zu dieser Arbeit m?chte der Autor Lothar Partzsch, Klaus D. Schmidt (beide Dresden) und Friedemann Spies (München) recht herzlich danken.     

彩票的法学解析

彩票是国家为筹集社会公益资金而发行的供人们自愿购买并据以取得获奖机会的凭证。汇集闲散资金,造福社会公益事业,是彩票的本质特征,也是彩票的道德生命和法律生命所在。彩票具有国家性、财产性、合同性、社会性等法律性质。彩票运作中包含着多重法律关系,其核心问题是发行人与购彩人之间的权利、义务如何配置。     

关于改进我国天然气管输定价方式的探讨

探索了我国现行天然气管输运价形成机制严重背离天然气市场发育的弊端，进而提出与国际接轨的建议，即通过分别确定管输企业年度应收服务费和按两部制设计用户运价率来制定管输价格。