Forecast of realized covariance matrix based on asymptotic distribution of the LU decomposition with an application for balancing minimum variance portfolio

We derive the asymptotic distribution for the LU decomposition, that is, the Cholesky decomposition, of realized covariance matrix. Distributional properties are combined with an existing generalized heterogeneous autoregressive (GHAR) method for forecasting realized covariance matrix, which will be referred to as a generalized HARQ (GHARQ) method. An out-of-sample forecast comparison of a real data set shows that the proposed GHARQ method outperforms other existing methods in terms of optimizing the variances of portfolios.     

From the blogosphere into the parliament: The role of digital technologies in organizing social movements

In this paper, we present a process model exploring the roles played by digital technologies (DTs) in the organization of collective action (CA) of social movements (SMs) at different points in their lifecycles. The process model, which is based on an exploratory case study of the Italian Five Star Movement, relates the environmental conditions to the working logic, structure and use of DTs at three different stages of the SMs. We explain how these choices are adopted at each stage to address internal and environmental challenges and how they create further challenges to be addressed to pass to the next stage. We further explore the dynamics between the logic of connective and collective action and reflect on the growing need for structures and control. By so doing, our work addresses the need for a better understanding of the coevolution between DTs and organizational structures and of the ways in which DTs are used to mobilize people to sustain CA along the SM lifecycle.     

北部湾城市群自然资本利用状况、空间分析与驱动因素

以北部湾城市群为例用三维生态足迹模型、偏最小二乘法、空间计量模型分析了其自然资本利用状况、空间相关性、驱动因素。结论:(1)城市群自然资本利用处于不可持续状态;(2)自然资本利用程度划分为低、中、高三类,城市也相应分成三类;(3)自然资本利用的主要驱动因素是人口因素、社会经济;(4)空间分析显示全局莫兰指数为正,空间集聚显著,表明自然资本利用存在空间正相关;空间误差模型拟合度最好,并证明自然资本存量占用与人口总量正相关,与GDP总额负相关。     

泸县农村宅基地有偿使用制度改革效果评价

[目的]宅基地有偿使用制度研究有利于推进宅基地制度改革,缓解无偿无限期带来的土地超占乱占和闲置问题。[方法]文章运用层次分析法和模糊综合评价法对2016年和2018年泸县农村宅基地有偿使用制度改革政策效果进行评价。[结果]政策的开展能有效推进村民自治建设进程,但政策的实施要注重公开透明性;有偿使用政策能有效缓解一户多宅、低效闲置、超占乱占等土地浪费现象实现土地的节约集约利用;政策的实施能有效地改善基础设施和农村面貌,但对泸县生产方式转变、新业态发展、农户生活水平提升影响力较小;总体来看农户对有偿使用政策满意度和支持度较高。[结论]针对当前有偿使用制度改革,该文认为宅基地有偿使用制度改革还应该完善有偿使用费收取管理政策,增强政策执行透明度;注重基层队伍建设,实现有偿使用费保值增值;合理选择安置模式,发展农村新业态;加强宅基地有偿使用与有偿退出的高效联动,推进宅基地制度改革进程。     

基于个性化的江西省乡村旅游空间分布及评价

［目的］通过对个性化的江西省乡村旅游区的空间分布进行研究，并对个性化的红色旅游资源进行评价，以期对乡村旅游的发展提供新的思考路径，建立具有个性化的乡村旅游体系。［方法］运用GIS102操作平台对江西省119个红色乡村旅游区的空间分布情况进行研究，通过计算最临近点指数、地理集中指数和核密度计算分析其空间分布特征。以资源要素价值、开发价值和社会效益组成评价层，下分14个指标，对江西省红色旅游资源进行评价研究。［结果］(1)江西省红色旅游区分布类型为集聚型，分布不均衡； (2)在评价准则层中，旅游资源要素价值权重最大，为0647 9，其次为社会效应，权重为0229 9，开发条件权重最低，为0122 2； (3)指标层权重排名前三位的依次为资源完整性、教育性和组织管理，权重值分别为0162 0,0116 5和0111 7。［结论］江西省乡村红色旅游区数量较多，但整体呈集聚型分布特点； 旅游资源要素价值权重最高，且整体资源禀赋较强，社会带动效应明显，具有极强的开发价值。     

Does justice affect brand advocacy? Online brand advocacy behaviors as a response to hotel customers’ justice perceptions

This study focuses on customers' information-sharing behavior in the context of online brand advocacy behavior regarding hotel brands. We aim to explain hotel customers' online brand advocacy behavior through three-sided justice evaluations (i.e., justice for employees, justice for the self, and global belief in a just world), and their hotel satisfaction. Hypotheses are tested by using survey data acquired from 688 individuals on Amazon's Mechanical Turk (MTurk) through partial least squares structural equation modeling (PLS-SEM). The findings show that customers' perceptions of justice for the self positively affect their hotel satisfaction, perceptions of justice for employees and the global belief in a just world positively affect online brand advocacy behavior, and hotel satisfaction also positively affects online brand advocacy behavior. We expand current research efforts on online brand advocacy research and provide theoretical and managerial implications for the development of marketing and management research and practice.     

Internal green integration and environmental performance: The predictive power of proactive environmental strategy,greening the supplier,and environmental collaboration with the supplier

The effect of proactive environmental strategies (PES) on corporate performance has been debated extensively among academics; however, the significance of the pathway of those strategies—internal green integration (IGI) through greening the supplier (GTS) and environmental collaboration with suppliers (ECS)—remains undecided. This study examines environmental performance (EP) through GTS, IGI, and ECS. It also examines the direct link between PES and IGI. A conceptual framework was designed following a rigorous review of the literature. A survey questionnaire was used to collect cross-sectional data from a random sample of manufacturing firms, obtaining 196 usable samples. Using AMOS, the structural equal modeling found a positive and significant impact of PES on IGI. Significant predictors of EP were GTS, IGI, and ECS. The findings of the study can provide managers with guidelines for dealing with business and environmental concerns. They can also contribute to creating strategies for environmental protection and management and reducing adverse effects on the environment. Finally, by examining the direct links between GTS, ECS, and EP, particularly in a developing context, the study may contribute to the literature of environmental policy.     

权力义务视角下完善向基层赋权的思考

2010年开始,向基层赋权作为行政体制改革的重要内容在全国范围铺开。从权力义务视角对其进行研究有现实的必要性。赋权的核心是行政权力的转移,以权力转移过程中涉及的诸要素为切入点,可以分析出多重权力关系和有关主体在其中的权力义务。在此基础上,通过保障行政相对人对于赋权的参与权、设计上级行政机关实施赋权的制度、消除上级行政机关赋权的依据问题和设计基层行政机关行使权力的制度等方式完善向基层赋权,既使行政机关能够有效推进行政体制改革,又能对行政权进行有效规范、保障行政相对人权利。     

秦迁陵县粮仓设置体系探讨--以出粮机构粮食来源问题为中心

除仓官外,秦迁陵县内的出粮机构还包括田官、离乡及司空等。它们并非都建有独立粮仓,所出粮食的来源也不尽一致。田官不设粮仓,它的出粮地是公共粮仓中的一间专属仓房。离乡建有供应该乡粮食开支的独立粮仓,且粮仓数量与该乡人口规模有关。小乡可能仅有一座粮仓,故有时会产生因储备不足而需要仓官额外输粮的问题。司空、发弩及■舍三者既未建有独立粮仓,也不如田官那般在公共粮仓内占有一间仓房,它们向外供应的粮食全都是由仓官转输。总之,秦迁陵县内设置的粮仓包括县级公共粮仓和离乡粮仓两类。田官、司空、发弩及舍虽承担了部分出粮职能,但并未给县内粮仓体系带来影响。