Three Corrected Score Tests for Generalized Linear Models with Dispersion Covariates

We develop three corrected score tests for generalized linear models with dispersion covariates, thus generalizing the results of Cordeiro , Ferrari and Paula (1993) and Cribari-Neto and Ferrari (1995) . We present, in matrix notation, general formulae for the coefficients which define the corrected statistics. The formulae only require simple operations on matrices and can be used to obtain analytically closed-form corrections for score test statistics in a variety of special generalized linear models with dispersion covariates. They also have advantages for numerical purposes since our formulae are readily computable using a language supporting numerical linear algebra. Two examples, namely, iid sampling without covariates on the mean or dispersion parameter oand one-way classification models, are given. We also present some simulations where the three corrected tests perform better than the usual score test, the likelihood ratio test and its Bartlett corrected version. Finally, we present a numerical example for a data set discussed by Simonoff and Tsai (1994) .     

外生冲击与房地产真实价格波动--对1998～2003年中国31省(市、区)的实证研究

文章首先根据经济学模型界定了两个重要指标:自相关系数与收敛系数.认为不同的外生冲击对这两个系数有不同的影响,而它们决定了房地产真实价格波动形态的差异.在此基础上,文章利用1998～2003年中国31个省(市、区)的面板数据对中国房地产市场进行了实证研究,其结论是,在真实人均可支配收入和真实建筑成本较高、真实税后住宅抵押贷款利率较低的地区有较大的自相关系数和较小的收敛系数,从而房地产真实价格具有更大的波动性.为使房地产真实价格在均衡价格附近平稳运行,降低开发成本和提高消费者购买成本能收到较好的效果.     

基于主成分分析的多元线性回归用水量模型研究——以安徽省为例

用水量的准确预测对水资源规划具有重要意义。根据统计资料,选取了八项主要影响用水量变化的指标。按照主成分分析法原理,运用少数综合因子对影响用水量变化的原有八项指标进行了综合和简化,并研究其贡献率及综合效应;分析了用水量增长的特点,选用Logistic方程对综合因子进行回归分析;结合多元线性回归方法,建立了安徽省用水量模型;拟合结果表明,模型具有较高的精度;运用该模型,对安徽省2010年的用水量进行了预测;为水资源规划与管理提供参考依据。     

紧凑城市与可持续发展的中国实证

中国城市发展是走郊区化之路,还是高密度的紧凑城市之路,取决于紧凑城市是否有利于可持续发展。文章以紧凑城市与可持续发展的关联机制为基础,提出相应的测度指标,利用回归模型、典型相关分析方法对两者的关联性进行实证研究,结果发现城市越紧凑越有利于经济、环境和社会的可持续发展,但并未引起资源消耗的显著改善。结论对于我国建设紧凑型城市、促进可持续发展无疑具有重要的政策启示。     

“一带一路”倡议下中国口岸出入境货运量的时空格局演变探究

口岸作为国家指定的对外开放门户,承担着国与国之间货物运输和人员往来的重要功能。"一带一路"倡议的实施促进了我国口岸的发展,带动了口岸经济与区域经济的发展,反过来进一步加强了与"一带一路"沿线国家的合作。本文利用口岸运行指标中的出入境货运量数据,借助探索性空间数据分析方法,对我国2011—2017年31个省(区、市)的口岸出入境货运量的时空格局进行分析。结果表明:"一带一路"倡议提出后,尤其是2015年后,我国口岸出入境货运总量呈现快速增长态势且存在显著的空间正相关性;三类口岸(水运、陆运和空运口岸)中,水运口岸存在更显著的、更强的空间相关性;各类口岸出入境货运量中,东部沿海地区水运呈现正向空间集聚现象,西部沿边地区陆运呈现极化现象。此外,本文对全国31个省(区、市)的地区货运总量也进行了空间动态分析,发现也存在空间相关性,且集聚效应在"一带一路"倡议提出后不断增强。在此基础上,为了更好地服务于"一带一路"建设,本文提出了提升各类口岸运输能力的相关对策建议。     

Portfolio Optimization under Lower Partial Risk Measures

Portfolio management using lower partial risk (downside risk) measures is attracting more attention of practitioners in recent years. The purpose of this paper is to review important characteristics of these riskmeasures and conduct simulation using four alternative measures, lower semi-variance, lower semi-absolute deviation, first order below targetrisk and conditional value-at-risk.We will show that these risk measures are useful to control downside risk whenthe distribution of assets is non-symmetric. Further, we will propose a computational scheme to resolve the difficultyassociated with solving a large dense linear programming problems resulting from these models. We will demonstrate that this method can in fact solve problems consisting of10⁴ assets and 10⁵ scenarios within a practical amount of CPU time.     

集值函数及向量值函数的两类线性算子逼近

本文得到了利用插值型线性算子列及积分型算子列逼近连续集值函数及连续向量值函数的收敛逼近阶。     

Real estate return correlations: Real-world limitations on relationships inferred from NCREIF data

Correlation estimates for returns between individual properties are subject to large inherent uncertainties due to limits on the amount of data that is likely to be available for the foreseeable future. After allowance for correlation sampling error, it is impossible to distinguish on an ex ante basis between the risk-reduction capabilities of mean-variance portfolio selection models and naive diversification without regard to property type or geographical location. The naive portfolio diversification strategies of typical institutional real estate portfolio managers are rational responses to limitations on the informational content of statistical analyses of historical real estate data.     

我国股份制商业银行薪酬激励有效性研究

我国股份制商业银行薪酬激励存在一些不足，原因在于薪酬激励的自身因素和薪酬环境因素两方面。自身因素主要包括忽视长期行为激励、缺乏同业竞争优势、轻视普通员工激励；环境因素主要有银行治理结构不完善、市场非充分有效、法规制度不健全等。本文通过对商业银行高管人员及普通员工的薪酬与业绩相关性进行实证检验，认为我国商业银行薪酬激励基本上是有效的，但是其有效性并不十分理想。据此，本文提出了提升我国商业银行薪酬激励有效性的具体建议：从微观层面看，优化薪酬激励机制：从中观层面看，强化商业银行治理结构；从宏观层面看，改善外部相关环境。