Some novel results on pairwise quasi-asymptotical independence with applications to risk theory

In this article we obtain some novel results on pairwise quasi-asymptotically independent (pQAI) random variables. Concretely speaking, let X₁, …, X_n be n real-valued pQAI random variables, and W₁, …, W_n be another n non negative and arbitrarily dependent random variables, but independent of X₁, …, X_n. Under some mild conditions, we prove that W₁X₁, …, W_nX_n are still pQAI as well. Our result is in a general setting whether the primary random variables X₁, …, X_n are heavy-tailed or not. Finally, a special case of above result is applied to risk theory for investigating the finite-time ruin probability for a discrete-time risk model with a wide type of dependence structure.     

Vine copula constructions of higher-dimensional dependent reliability systems

Copulas have proved to be very successful tools for the flexible modeling of dependence. Bivariate copulas have been deeply researched in recent years, while building higher-dimensional copulas is still recognized to be a difficult task. In this paper, we study the higher-dimensional dependent reliability systems using a type of decomposition called “vine,” by which a multivariate distribution can be decomposed into a cascade of bivariate copulas. Some equations of system reliability for parallel, series, and k-out-of-n systems are obtained and then decomposed based on C-vine and D-vine copulas. Finally, a shutdown system is considered to illustrate the results obtained in the paper.     

去工业化促进了服务业效率提升吗

世界产业发展史表明,当一国进人工业化中后期,随着生产效率大幅提升,其产业结构演变亦呈现出明显的去工业化特征.以工业化国家为参照,现阶段我国人均收入远未达到工业化国家去工业化时的水平,此时收缩工业产出和就业规模,可视为一种被动去工业化,客观上不利于服务业效率的提升.本文利用2005-2014年我国制造业和服务业数据估计了去工业化对服务业效率的影响.在控制住市场结构和所有制结构等因素的影响后,研究结果显示:①去工业化与服务业效率之间呈现负相关关系;②去工业化通过提高劳动力成本对传统服务业效率产生负效应;③去工业化通过削弱制造业对服务业的有效需求从而不利于生产性服务业效率的提升.     

融资融券制度与市场定价效率——基于卖空摩擦的视角

我国融资融券制度不同于国外成熟市场的一个重要特征是存在较大的卖空摩擦,但这一卖空摩擦对市场定价效率的影响及其作用机制尚未被研究揭示.本文运用双重差分固定效应模型、处理效应模型和倾向性匹配双重差分模型,研究了融资融券制度中的卖空摩擦对市场定价效率的影响及其内在机制.实证结果表明,融资融券制度中的卖空摩擦抑制了市场参与者对公司特质信息的充分挖掘,促使其过度利用市场或行业信息进行交易,从而延缓了公司特质信息融入股价,加速了市场或行业信息融入股价,最终加剧了股价同涨同跌现象,不利于市场定价效率的提高.本文研究结论为监管部门合理扩大融资融券标的范围、降低交易成本和交易门槛,营造高效的市场环境提供了依据和思路.     

基于Theil不等系数的C-IGOWLA算子的区间组合预测模型

传统的组合预测方法通常是针对非区间数据在最优准则下来建立最优预测模型的,但实际,中在不确定环境下样本数据和预测值序列均以区间数形式给出,因此有必要研究区间组合预测模型.文章引进连续区间诱导广义有序加权对数平均算子(C-IGOWLA)的概念,以Theil不等系数作为最优准则,提出了一种新的基于Theil不等系数的C-IGOWLA算子的区间组合预测模型,并结合实例验证了模型的有效性.     

中国省域大气环境效率的测算

基于区域技术异质性假定与共同边界理论,文章将大气污染排放物视为非期望产出,利用考虑投入产出松弛变量的SBM-Undesirable方法系统考察2006-2013年中国省域大气环境效率与大气环境治理技术的差异性,运用面板计量Tobit回归模型定量考察省域大气环境效率水平及其治理技术的影响机制.结果表明,中国大气环境效率较低且区域差异明显,三大区域之间大气环境治理技术落差较大,大气污染减排潜力巨大;经济增长、产业结构优化、科技创新、提升贸易开放度有利于促进大气环境效率及其治理技术的改善,相比之下,煤炭消费比重的提高与财政分权则起到了明显抑制作用.     

The Aging Semantic Differential in Mandarin Chinese: Measuring Attitudes toward Older Adults in China

ABSTRACT

The Aging Semantic Differential (ASD) is the most widely used instrument to measure young people’s attitudes towards older adults. This study translated the ASD to Mandarin and examined its psychometric properties. The Mandarin-ASD contains three latent factors (Personality and Mental Health, Societal Participation, and Physical) that have high internal reliability and reasonable discriminate validity. Social work researchers, practitioners and allied professionals may utilize the ASD-Mandarin instrument to measure young people’s attitudes towards older adults in China. We issue a call for a universal-ASD that can be applied across different cultural contexts.     

The Association Between the New Rural Cooperative Medical System and Health Care Seeking Behavior Among Middle-Aged and Older Chinese

The new rural cooperative medical system (NCMS) is the primary form of social insurance in rural China. This study aims to explore how the NCMS influences the health care seeking behaviors of middle-aged and older Chinese, considering the family and community contexts. A series of multi-level (three-level) models using data from the first wave of the China Health and Retirement Longitudinal Study (CHARLS) are used. We find that the presence of NCMS coverage has a statistically significant association with seeking inpatient and outpatient care but not physical checkups among middle-aged and older rural Chinese: Rural residents insured by NCMS were more likely to seek inpatient and outpatient care than people who were not insured. Other factors at the individual level (such as self-perceived health and number of doctor-diagnosed chronic diseases), the family level (such as living arrangements and household expenditures), and the community level (such as the presence of township hospitals within the community) are also significant predictors of health care seeking behaviors.     

A socio-ecological perspective of urban green networks: the Stockholm case

Landscape fragmentation threatens habitats, biodiversity and other ecosystem services. In tackling this threat, the dynamic processes of social-ecological systems should be recognised and understood. Although network analysis based on graph theory has been recognised as an efficient way of spatially understanding landscape or habitat connectivity, only few studies have offered specific approaches or suggestions for integrating detailed social-ecological values into geographical distributions. As a contribution to bridging this gap, this paper introduces a social-ecological network model for the issue of landscape or habitat fragmentation applied to the case of Stockholm, Sweden. Graph theory was used in combination with sociotope and biotope maps for simple visualisation of network situations in two-dimensional maps. The European crested tit (Lophophanes cristatus), European common toad (Bufo bufo) and human beings were selected as indicator species, based on a landscape ecology analysis in Stockholm Municipality in 2009. Slope, land use and human disturbance maps were assessed in order to decide cost values of travelling from node to node. Lease-cost-path accumulation was used to create ideal reference maps of green networks. Three separate maps were then developed for suggesting efficient routes for three indicators in city scale that mainly connect from the Royal National City Park to the other parts of the city. The model in Hjorthagen neighbourhood to highlight two practical paths that link this fragmented community to its neighbouring park areas. Findings make it possible to address two scales of network improvement strategies, namely first for the city-scale green network that connects geographical habitats (nodes) and the regional green wedges of the city, and the second that of neighbourhood links between habitats in detailed layers of green networks. Strategic improvement potentials are presented based on ideal reference maps of green networks correspondingly.