Bayesian estimation of the efficient frontier

In this paper, we consider the estimation of the three determining parameters of the efficient frontier, the expected return, and the variance of the global minimum variance portfolio and the slope parameter, from a Bayesian perspective. Their posterior distribution is derived by assigning the diffuse and the conjugate priors to the mean vector and the covariance matrix of the asset returns and is presented in terms of a stochastic representation. Furthermore, Bayesian estimates together with the standard uncertainties for all three parameters are provided, and their asymptotic distributions are established. All obtained findings are applied to real data, consisting of the returns on assets included into the S&P 500. The empirical properties of the efficient frontier are then examined in detail.     

一类稀疏投资组合双层参数估计模型及其应用

带基约束的投资组合问题是近年来投资组合领域的热点问题,但是参数不确定性直接影响了模型的效果。带基约束的投资组合问题所涉及的参数不仅包括以往研究认为非常重要的预期收益率,还包括控制投资组合规模的稀疏度,尤其是最优稀疏度估计方面的专门研究还十分匮乏。为了使带基约束的投资组合模型更好地为投资决策服务,本文从投资者效用出发,用双层规划的思想构建了带基约束的投资组合双层参数估计模型。然后根据模型的特点,设计了无导数优化算法框架,并基于ADMM对算法子问题进行求解。本文实验针对真实的市场数据给出了预期收益率和最优稀疏度的估计,接着通过与等权重策略和含上下界约束的均值-方差模型进行比较,说明了模型及算法的有效性和实用性。最后,将本文提出的双层参数估计模型推广到了更一般的形式。     

DEGENERACY AND THE (MIS)INTERPRETATION OF SENSITIVITY ANALYSIS IN LINEAR PROGRAMMING

Under conditions of degeneracy, sensitivity analysis information such as cost and right-hand-side ranges, which are produced by standard linear programming procedures used in commercial codes, can be misleading. From a managerial perspective, the interpretation of such information can be erroneous. In this paper we present these problems, explain their occurence with elementary examples, and discuss procedures for their resolution.     

农村社区建设的参数分析

农村社区建设应坚持科学发展观,按照"生产发展、生活宽裕、乡风文明、村容整洁、管理民主"的社会主义新农村建设目标要求,建设人与自然和谐相处的村民"宜居社区"和"精神家园"。社区建设涵盖经济收入指数、人居环境指数、居民幸福指数、社区参与指数、平安康乐指数、福利保障指数、社区归属感等参数。     

Measuring Active Citizenship through the Development of a Composite Indicator

This article defines Active Citizenship within a European context as a broad range of value based participation. It develops a framework for measuring this phenomenon which combines the four dimensions of Protest and Social Change, Community Life, Representative Democracy and Democratic values. The European Social Survey 2002 is used to populate the framework as this survey provided the best data coverage available and covered 19 European Countries. In total 61 indicators were selected. A composite indicator (CI), The Active Citizenship Composite Indicator (ACCI), is built using the framework provided and using experts’ weights. In addition, the robustness of the results is tested using sensitivity analysis. The limitations to the ACCI are explained in terms of the limitation of the data availability in particular concerning the new forms of participation and less organised forms of participation. Nevertheless, ACCI proved to be statistically robust and reliable and proved to be a useful tool for monitoring levels of citizenship in Europe. The results of ACCI exhibit interesting and quite distinct regional patterns. The results showed that the Nordic countries, and in particular Sweden, have the highest rate of Active Citizenship, followed by Central Europe and Anglo-Saxon countries. Mediterranean countries are next followed by Eastern European countries that close the ranking.

“三驾马车”与福建经济增长的动态关系——基于时变参数状态空间模型的实证研究

基于福建省地区生产总值、消费、投资和净出口数据,构建了揭示"三驾马车"与福建经济增长间动态关系的变参数状态空间模型,分析了其动态变化的轨迹与趋势。实证结果表明:"三驾马车"对福建经济增长的拉动作用具有明显的阶段性特征,虽然投资的拉动作用一直超过消费和净出口,但2005年后消费的拉动作用在稳步增强而投资的拉动作用在逐年减弱,说明福建经济对投资的依赖性正在下降,经济转型早已开始并且趋势稳定,正在稳步进入可持续的发展轨道,政府无需做过多的干预。     

金融结构对产业结构影响的时变特征研究——基于SUR和TVPSS模型的实证检验

金融结构与产业结构的关系一直是学术界的研究热点.文章利用中国1998—2017年的年度数据,构建似不相关回归模型从金融结构规模、效率及深化的角度分析金融结构对产业结构合理化和高级化的影响,建立时变参数状态空间模型描绘了金融结构对产业结构合理化和高级化的动态冲击.实证分析结果表明:金融结构规模提高产业结构合理化水平,促进了产业结构高级化;金融结构效率提高产业结构合理化水平,抑制了产业结构高级化;金融结构深化降低产业结构合理化水平,促进了产业结构高级化.金融结构规模、金融结构效率及金融结构深化对产业结构合理化和高级化的冲击均呈现出时变特征;金融结构对产业结构合理化的影响滞后于其对产业结构高级化的影响.金融结构对产业结构的冲击波幅呈现出前期波动大、后期较为平缓的状态,部分金融结构变量对产业结构的动态冲击呈现出"长尾"现象.当前的中国金融结构已经不适合当前的产业结构,需调整金融结构,以提升产业结构合理化水平和高级化水平.     

心律波动信号的1/f噪声特性分析

心律波动信号具有1/f噪声特性,是非平稳的。该文采用平均功率谱密度方法,分析了基于平均功率谱密度和最小二乘拟合法求正常人和心脏充血患者的心律波动信号的谱参数,发现根据谱参数可以定量地区分正常人与心脏充血患者:大部分正常人的心律波动信号的谱参数大于1,而大部分心脏充血患者的心律波动信号的谱参数小于1,该结论可为心脏病的诊断与预诊断提供一种辅助手段。     

娄烦方言语气词“哩”的功能及参项意义

文章应用变换分析法,多角度分析了娄烦方言语气词“哩”单一的标志现在完成或实现的功能,确定了它在句子中的句法地位。并以此为基础,分析了其标志域(INDICATIVESCALE)。最后根据语气词标志域语义性质特点,确定谓语分类的两个参项,并建立测试框架,从形式上得以验证,以此来说明娄烦方言语气词的参项意义。以期对娄烦方言语气词“哩”做全面的描写和分析。     

网络社会公众同情形成过程中的媒介作用机制研究

在网络社会的社会实践过程中,信息传递的充分和对称并没有避免公众同情与事实本身形成偏差的出现。由于信息技术改变了人们的生活方式,传播网络上的发声成为了节点化生活中的人们参与社会事务的主要手段。社会资本运动的核心转变为文化资本,公众同情作为传播过程中核心节点——话题序参量媒体参与社会资本活动的重要工具,在公共舆论事件的发展和演变过程中起着重要的作用。