少数民族地区旅游开发条件比较研究--以甘肃省肃南县和贵州省黎平县为例

文章通过特尔菲法建立少数民族地区旅游开发条件评价的指标体系 ,利用该指标体系对甘肃省肃南县和贵州省黎平县进行单项评分和综合评价 ,并依据分析结果对两地旅游业的发展提出建议。     

因子模型门槛效应的LM和Wald检验及其统计性质研究

门槛因子模型可以有效地刻画高维度时间序列的共变特征和区制转换行为,具有良好的可解释性和预测能力。针对因子载荷矩阵存在的门槛效应,本文提出了拉格朗日乘子和沃尔德检验方法,并给出了渐近分布,相关结果表明以上检验统计量具有良好的大样本性质和有限样本表现。在实证部分,以我国股市的行业指数作为研究对象,通过构建门槛因子模型来刻画我国股票市场波动的共变性特征和非对称效应。实证结果表明基于门槛因子模型可以很好地刻画中国股市行业收益率波动的共变特征和区制转换行为。     

自媒体时代历史虚无主义思潮的传播及其反制

历史虚无主义在意识形态层面否定马克思主义的指导地位与唯物史观,歪曲丑化了中国共产党的领导。历史虚无主义思潮借助自媒体平台呈现出的碎片化、隐匿化与庸俗化倾向,在当下自媒体平台肆意传播,在社会上造成了极其恶劣的影响。在此背景下,必须深入分析历史虚无主义思潮在自媒体平台的传播方式及其规律,有针对性地提出相应的反制策略,在重建马克思主义唯物史观的同时,营造健康的网络道德教育环境。     

创投机构声誉、减持退出收益与公司业绩的影响效果——基于我国创业板制造业上市公司的实证分析

本文选取创业板上市公司为样本,实证创投机构声誉、减持退出行为收益与上市公司经营业绩的影响效果。研究发现:有创投参投的上市公司其经营业绩并未能明显优于无创投参投的上市公司,创投减持退出并未造成上市公司业绩显著下滑,创投机构减持行为与参投上市公司的业绩无显著关联;创投机构会发生聪明投资者的择时减持行为,借此获取超额减持收益;不同声誉创投机构退出行为的自我约束效力不同,高声誉创投机构减持退出行为更加理性。?更多还原     

Estimating Abundance from Presence–Absence Maps via a Paired Negative‐Binomial Model

The estimation of abundance from presence–absence data is an intriguing problem in applied statistics. The classical Poisson model makes strong independence and homogeneity assumptions and in practice generally underestimates the true abundance. A controversial ad hoc method based on negative‐binomial counts (Am. Nat.) has been empirically successful but lacks theoretical justification. We first present an alternative estimator of abundance based on a paired negative binomial model that is consistent and asymptotically normally distributed. A quadruple negative binomial extension is also developed, which yields the previous ad hoc approach and resolves the controversy in the literature. We examine the performance of the estimators in a simulation study and estimate the abundance of 44 tree species in a permanent forest plot.     

A Necessary Condition for the Strong Oracle Property

A problem of using a non‐convex penalty for sparse regression is that there are multiple local minima of the penalized sum of squared residuals, and it is not known which one is a good estimator. The aim of this paper is to give a guide to design a non‐convex penalty that has the strong oracle property. Here, the strong oracle property means that the oracle estimator is the unique local minimum of the objective function. We summarize three definitions of the oracle property – the global, weak and strong oracle properties. Then, we give sufficient conditions for the weak oracle property, which means that the oracle estimator becomes a local minimum. We give an example of non‐convex penalties that possess the weak oracle property but not the strong oracle property. Finally, we give a necessary condition for the strong oracle property.     

Validation of Nonparametric Two-sample Bootstrap in ROC Analysis on Large Datasets

The nonparametric two-sample bootstrap is applied to computing uncertainties of measures in receiver operating characteristic (ROC) analysis on large datasets in areas such as biometrics, speaker recognition, etc. when the analytical method cannot be used. Its validation was studied by computing the standard errors of the area under ROC curve using the well-established analytical Mann–Whitney statistic method and also using the bootstrap. The analytical result is unique. The bootstrap results are expressed as a probability distribution due to its stochastic nature. The comparisons were carried out using relative errors and hypothesis testing. These match very well. This validation provides a sound foundation for such computations.     

Combining Inverse Probability Weighting and Multiple Imputation to Improve Robustness of Estimation

Inverse probability weighting (IPW) and multiple imputation are two widely adopted approaches dealing with missing data. The former models the selection probability, and the latter models data distribution. Consistent estimation requires correct specification of corresponding models. Although the augmented IPW method provides an extra layer of protection on consistency, it is usually not sufficient in practice as the true data‐generating process is unknown. This paper proposes a method combining the two approaches in the same spirit of calibration in sampling survey literature. Multiple models for both the selection probability and data distribution can be simultaneously accounted for, and the resulting estimator is consistent if any model is correctly specified. The proposed method is within the framework of estimating equations and is general enough to cover regression analysis with missing outcomes and/or missing covariates. Results on both theoretical and numerical investigation are provided.     

历史地理学研究中GIS的认知过程及其人类因素考量

GIS技术在历史地理学研究领域的引入,为21世纪历史地理学沉淀积累和蓄势待发提供了新的研究视角和路径。随着GIS技术的普遍运用,尤其是在历史自然地理领域的使用,遂成为该研究方向创新和发展的重要因素。不过,GIS技术在人文地理研究领域中的运用情况则略显滞后,其实质在于受人类因素影响下历史文献数据化的标准问题。此外,GIS技术自身定位不再局限于一种研究手段,而是呈现出向新方法和理论高度的认知过程。     

我国金融控股公司立法必要性探析

金融控股公司作为我国金融“分业”体制下实现“混业经营”目的的一种组织创新模式,在我国的发展日益迅速,而我国立法空缺的现状却严重阻碍了其健康发展,也造成了极大的金融风险。文章利用历史分析、比较分析和法经济学的方法,通过对我国金融业历史发展演进的纵向考察,对世界金融控股公司普遍立法现状的横向比较以及金融控股公司作为一种经济组织形式与我国金融立法关系的分析,论证了我国金融控股公司立法的必要性。