Variance estimation based on blocked 3×2 cross-validation in high-dimensional linear regression

In high-dimensional linear regression, the dimension of variables is always greater than the sample size. In this situation, the traditional variance estimation technique based on ordinary least squares constantly exhibits a high bias even under sparsity assumption. One of the major reasons is the high spurious correlation between unobserved realized noise and several predictors. To alleviate this problem, a refitted cross-validation (RCV) method has been proposed in the literature. However, for a complicated model, the RCV exhibits a lower probability that the selected model includes the true model in case of finite samples. This phenomenon may easily result in a large bias of variance estimation. Thus, a model selection method based on the ranks of the frequency of occurrences in six votes from a blocked 3×2 cross-validation is proposed in this study. The proposed method has a considerably larger probability of including the true model in practice than the RCV method. The variance estimation obtained using the model selected by the proposed method also shows a lower bias and a smaller variance. Furthermore, theoretical analysis proves the asymptotic normality property of the proposed variance estimation.     

Noninformative priors for the between-group variance in the unbalanced one-way random effects model with heterogeneous error variances

For the unbalanced one-way random effects model with heterogeneous error variances, we propose the non-informative priors for the between-group variance and develop the first- and second-order matching priors. It turns out that the second-order matching priors do not exist and the reference prior and Jeffreys prior do not satisfy a first-order matching criterion. We also show that the first-order matching prior meets the frequentist target coverage probabilities much better than the Jeffreys prior and reference prior through simulation study, and the Bayesian credible intervals based on the matching prior and reference prior give shorter intervals than the existing confidence intervals by examples.     

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.     

论道光年间滇南地区土司“文化治边”之举措——以《滇事杂档》史料为中心

道光年间滇南地区土司依靠清王朝授予的诰敕、号纸、印信等信物取得合法统治权之后,他们通过治边文化软实力的浸润,采取多种举措体现自己的权力象征,以实现“文化治边”的目标。具体而言,“文化治边”举措有四：一是在物质文化方面,土司衙署的建立;二是在制度文化方面,印信号纸的获得;三是在行为文化方面,土司法令的施行;四是在精神文化方面,表征系统、话语体系和意识形态等文化权力结构的建立。《滇事杂档》相关史料中以文治和教化等文化权力表征体系来治理滇南土司地区的思想,既是对清代中期官僚政治的认识与理解,又是对道光年间土司文化治权的阐述和诠释。     

均值—条件风险价值模型有效前沿分析——以含无风险资产和持有期为研究视角

从有效投资组合的角度构建持有期下含有无风险资产的均值—条件风险价值模型,用Lagrange乘子法对该模型求解,可得到:一定条件下,新模型的有效前沿与均值—方差模型有效前沿是一致的;且当借贷利率不同时,新模型的有效前沿可以根据组合预期收益率与借贷利率的不同关系,由线段、双曲线以及射线三个部分组合而成。     

利益相关者视角下的企业社会责任研究——以山东省1400家企业问卷调查为例

企业履行社会责任已经成为90年代以来企业界和理论界的共识,利益相关者理论为企业社会责任研究提供了新的视角和框架,按照利益相关者属性的不同可对其进行分类研究.在对山东省1400家企业的调查研究基础上,提出利益相关者的三维金字塔模型,以企业规模、企业性质和企业生命周期为变量考察三个维度社会责任表现的差异性,为企业的社会责任决策提供新的思路,为政府部门制定提升企业社会责任行为表现的政策提供新的视角和依据.     

行为金融学的发展与探索

本文通过对行为金融相关文献的回顾 ,指出了当前研究的不足 ,并探索了行为金融理论的发展需要解决的难题及未来研究的方向。同时 ,本文指出了行为金融理论作为一门独立学科应具备的基本条件 ,为行为金融理论整合为一门学科提出了自己的意见     

中国农垦全要素生产率的随机前沿分析

文章利用随机前沿生产函数模型,对2001—2006年中国农垦一、二、三产业投入产出数据进行计量分析,根据回归结果,把农垦全要素生产率增长分解为前沿技术进步、相对前沿技术效率、规模经济效率和资源配置效率的变化。进一步分析发现：要素投入增长是农垦产出增长的主要视力来源,农垦全要素生产率增长和产出增长不存在显著的相关关系;农垦前沿技术进步显著,是农垦全要素生产率增长的主要源泉;二、三产业相对前沿技术效率的恶化是阻碍农垦全要素生产率增长的主要障碍。     

会计制度与税务制度差异的研究

由于企业会计制度与税务制度所规范的对象和目的不同,会计核算和税务核算之间始终存在着一定的差异。我国现行的会计制度,在会计核算原则、会计政策及会计核算实务等方面都与现行的税务制度存在着较大的差异,而这些差异很可能会导致国家税源的流失,并容易引起征纳双方的纠纷,造成纳税调整增多,甚至不能正确地确认纳税人权益,也给企业避税创造了机会。因此,应加快我国税收制度的改革,减少会计制度与税务制度的差异,确保会计核算的准确性和企业依法纳税。