Testing non-nested log-linear models with pseudo estimator

As the number of random variables for the categorical data increases, the possible number of log-linear models which can be fitted to the data increases rapidly, so that various model selection methods are developed. However, we often found that some models chosen by different selection criteria do not coincide. In this paper, we propose a comparison method to test the final models which are non-nested. The statistic of Cox (1961, 1962) is applied to log-linear models for testing non-nested models, and the Kullback-Leibler measure of closeness (Pesaran 1987) is explored. In log-linear models, pseudo estimators for the expectation and the variance of Cox's statistic are not only derived but also shown to be consistent estimators.     

Solving the Stochastic Growth Model by Parameterizing Expectations

This article describes a method for solving the one-good stochastic growth model by parameterizing the expectations part of the stochastic Euler equation. The conditional expectation is specified as a function of the state of the system, and the parameters of that function are estimated to solve the model. The article includes a discussion of how to find the parameters of the function and determine systematically the complexity of the functional form necessary to solve the model.     

Simulation of the p-generalized Gaussian distribution

In this paper, we introduce the p-generalized polar methods for the simulation of the p-generalized Gaussian distribution. On the basis of geometric measure representations, the well-known Box–Muller method and the Marsaglia–Bray rejecting polar method for the simulation of the Gaussian distribution are generalized to simulate the p-generalized Gaussian distribution, which fits much more flexibly to data than the Gaussian distribution and has already been applied in various fields of modern sciences. To prove the correctness of the p-generalized polar methods, we give stochastic representations, and to demonstrate their adequacy, we perform a comparison of six simulation techniques w.r.t. the goodness of fit and the complexity. The competing methods include adapted general methods and another special method. Furthermore, we prove stochastic representations for all the adapted methods.     

Distributing Journals to the World

Abstract

In 2001, a number of initiatives began for distributing research journals to parts of the world where they are otherwise not accessible. This “Balance Point” reports on two publishers whose journals are now more broadly available in developing nations. HighWire Press offers both a free back issue archive and a developing countries initiative. Blackwell Publishing is working with a Russian consortium to make journals available to Russian universities and with nongovernmental organizations to provide free or nearly free access to biomedical journals in a number of developing nations. Serials Review 2002; 28:113–115.     

投资组合均值-方差模型和极小极大模型的实证比较

本文针对传统的Markowitz均值-方差(MV)模型和Young(1998)提出的极小极大(Minimax)模型进行了实证比较研究。我们将2001年上证30指数的实际数据分成两部分,一部分作为样本数据进行优化组合分析,另一部分作为非样本数据进行模拟投资,检验绩效。结果发现:在同样的样本数据下,由两种模型的解描绘的风险-收益率有效前沿图非常相似;将两组模型的最优解分别进行模拟投资,Minimax模型的结果明显优于MV模型。本文的实证结果检验了Minimax模型的理论结论,表明其在实际投资中具有良好的可操作性和实用价值。     

企业经理风险决策行为的实证研究

本文报告的两项研究系统深入地探讨了中国企业经理的风险决策行为。在研究一中,214名企业经理填答了效用测量表;在研究二中,82名企业经理填答风险决策情景模拟表。结果发现,个人特征(如性别、职位、所在企业的性质与规模等)、决策任务特征(如结果值的符号与大小)以及决策环境特征(如企业文化、企业经营状况、上司的风险态度等)均是影响企业经理风险决策行为的关键变量。本文为建立风险决策行为的理论或模型提供了基本的参考资料。     

两类广义卷积

把定义在半直线Ｒ＋＝［０，∞）上概率测度的广义卷积推广到了紧空间Ｒ＋＝［０，∞］上．讨论了与连续性、单位元有关的性质．根据单位元的可能性，导出了两类广义卷积，研究了它们之间的关系．比较了本文所用的推广方法与Ｕｒｂａｎｉｋ的推广方法之间的联系．     

摸准症结 积极推进“四五”普法工作

普法是依法治国、建立社会主义国家的重要举措.在我国全面开展"四五"普法之际,我们应当积极寻找普法工作的不足,对症下药,采取有力措施推进普法工作.     

“三个代表”重要思想与推进“三个文明”建设

阐述了"三个代表"和"三个文明"的内涵及联系,以及贯彻"三个代表"重要思想的基本要求及推进"三个文明"建设的具体措施.