机构投资者信息挖掘、羊群行为与股价崩盘风险

聚焦机构投资者决策行为背后的信息驱动因素，选取2007年～2017年沪深A股作为研究样本，构建了机构投资者信息挖掘能力的度量指标，分析机构投资者信息挖掘能力的差异对股价崩盘风险的影响效应及其中介路径.实证发现，持股机构投资者信息挖掘能力的差异程度越大，则越能减缓样本股票的股价崩盘风险.多重链式中介效应检验表明羊群行为在其中起到了部分中介效应，也即信息挖掘能力差异会导致机构投资者的羊群行为程度降低，进而缓解了股价崩盘风险.在不同市场环境中，熊市中这种缓解效应相较于牛市更加明显.同时，良好的公司内外部环境不仅能有效降低股价崩盘的风险，也可以加强机构投资者信息挖掘能力差异性对股价崩盘风险的缓解效应.研究结论为全面认识机构投资者信息挖掘能力以及如何降低股价崩盘风险提供了借鉴.     

机构投资者交叉持股与企业违约风险

基于公司治理外部性理论,本文实证检验了机构投资者交叉持股对企业违约风险的影响。研究发现,机构投资者交叉持股能够有效降低企业违约风险。中介机制检验表明,交叉持股主要通过完善的公司治理和额外的信息优势两条渠道对企业违约风险产生影响。在进一步研究中,本文证实分析师监督、审计师监督、企业所在地开通高铁均能够与机构投资者交叉持股发挥协同治理效应,更大程度上降低企业违约风险。本研究打破了传统关注单个企业公司治理的讨论框架,不仅有利于拓展公司治理外部性在资本市场中的应用,也能够为上市公司构建合理的风险管控体系提供有益借鉴。     

哪些因素影响了股市风险传染？——来自行业数据的证据

防范系统性风险是我国资本市场改革发展的重要议题,风险传染(risk contagion)是系统性风险的重要特征之一,作为资本市场最主要部分的股票市场,其行业间的风险传染愈益凸显。本文采用Δ CoVaR结合时变SJC-Copula的方法,测算了我国股市行业间产生风险传染和遭受风险传染的程度,并基于实际联系和金融联系实证检验了行业间产生和遭受风险传染的影响因素。研究结果表明,我国股市行业间的风险传染具有异质性和时变性;行业的关联程度越高,信息透明度越差,对其他行业股票产生风险传染的程度越高;行业的关联程度越高、信息越不透明、股票流动性越差,遭受其他行业风险传染的程度越高;投资者情绪能在一定程度上解释行业股票风险传染的时变性,投资者情绪越悲观,行业间的风险传染程度越高。     

“国家队”救市、股价波动与异质性风险

2015年～2016年股灾以来,"国家队"救市是否起到了稳定市场的作用,受到了业界和学界的广泛关注.本研究利用2015年第三季度至2016年第四季度A股上市公司机构持股数据,探讨"国家队"救市对股价波动的影响.研究结果表明:"国家队"持股有效降低了股票价格的波动,并且这一作用显著区别于其他机构投资者;"国家队"持股稳定股票价格主要体现在对异质性波动的降低上,对系统性波动则没有显著影响.进一步研究发现,"国家队"持股通过改善信息环境、降低噪声交易、稳定投资者情绪以及减少投资者异质性信念来降低异质性波动.本研究拓展了政府干预市场和机构投资者相关的发现,对危机期间资本市场监管和系统性风险防范化解相关政策的制定具有启示意义.     

股票特质波动率、股票收益与投资者情绪

从理论和实证两个角度分析股票特质波动率、股票收益与投资者情绪之间的动态关系。将受投资者情绪影响的噪声投资者引入Merton基于不完全信息的市场均衡模型,以2007年至2012年沪、深两市A股上市公司数据为样本,运用有向无环图(DAG)技术识别SVAR模型,实证检验股票特质波动率与股票收益和投资者情绪的相关性。研究结果表明,股票特质波动率与股票收益正相关;股票收益率对股票特质波动率的弹性,随着投资者情绪的增加和噪声投资者比例的上升而增大。投资者情绪和股市流动性是影响中国股票市场高特质波动股票与低特质波动股票截面收益差异大小的重要原因。投资者越乐观、市场上流动性越强,高特质波动组合收益率与低特质波动组合收益率的截面差异就越大。研究结果有利于加深对投资者行为的认识,从更符合中国资本市场情况的角度分析股票特质波动率与股票收益的关系。     

知识产权保护、信息不对称与高科技企业资本结构

企业资本结构的研究是财务研究的一大重点。本文以高科技企业为研究对象,将知识产权保护水平引入到解释企业资本结构问题的研究中,探讨知识产权保护水平对企业信息不对称程度的影响,进而影响企业资本结构的可能影响路径。研究发现:知识产权保护水平越高,在资本市场融资时企业的内外部信息不对称程度越低,企业越倾向于股权融资;信息不对称水平是知识产权保护影响高科技企业资本结构的中介变量。研究结果表明知识产权保护水平的提高可有效降低信息不对称程度,可帮助企业吸引战略投资者的加入,进而改善企业的资本结构,拓宽高科技企业的融资渠道,降低财务风险。     

中国证券市场的投资者情绪研究

从行为金融学角度,以2004年1月～2008年6月中国证券市场基金和股票的交易数据为研究样本,采用面板数据模型和动态组合分析方法系统考察中国投资者情绪与股票收益率、股票的市场关注程度、公司规模之间的联系.通过建立基于资金流量的投资者情绪指标,详细探讨投资者情绪对不同股票收益率变化的敏感性,揭示投资者情绪的形成原因、影响因素及其变化趋势.研究结果表明,股票收益率的波动随着投资者情绪的提高而增强;市场关注度越高的股票,投资者赋予的情绪越低;投资者对股票的情绪波动随着公司规模的增加而减弱.实证检验的结果验证了投资者情绪在中国股票市场中的重要作用,因此关于证券市场投资者情绪运行模式的研究对于中国资本市场泡沫的预警、监管机构制定政策都具有现实意义.     

机构投资者持股与股价崩盘风险的关系——基于市场变量的检验

"机构投资者持股对股价崩盘风险的影响是正向还是负向?现有研究文献并没有得到一致的结论，本文认为这个问题需要通过对市场条件进行细分来深入研究.为此，本文以2011年~2015年我国A股上市公司为样本，采用门限模型研究机构投资者持股对股价崩盘风险的影响是否会因市场效率和市场化程度的不同而发生变化.研究发现:机构投资者持股与股价崩盘风险之间存在市场效率和市场化程度的门限效应:当市场效率处在高水平时，机构投资者持股会降低股价崩盘风险，当市场效率处在低水平时，机构投资者持股会加剧股价崩盘风险;上市公司所在地区市场化程度处在高水平时，机构投资者持股会降低股价崩盘风险，上市公司所在地区市场化程度处在低水平时，机构投资者持股会加剧股价崩盘风险;在目前我国的整体市场环境下，机构投资者持股会加大股价崩盘风险."     

百股义士:投服中心行权与中小投资者保护——基于投服中心参与股东大会的研究

2014年证监会牵头成立中证中小投资者服务中心,是我国资本市场投资者保护的重大制度创新.研究投服中心对中小投资者保护的切实所用在理论和实践层面具有重大意义.鉴于此,本文使用手工整理的投服中心数据,系统分析投服中心的行权方式和运行规律,以及投服中心持股行权在中小投资者保护中的作用.研究结果显示:1)投服中心倾向关注财务状况较差、内部治理质量低、大股东和内部人控制程度低的民营企业;2)投服中心持股行权能够降低大股东和中小投资者间的信息不对称,且带动更多的中小投资者积极参与公司治理;3)投服中心关注某上市公司的公告能引起显著的市场反应,体现为被关注的公司受到更低的累计市场异常回报率.上述结果表明投服中心持股行权能够显著提高中小投资者保护.本研究首次系统地检验了投服中心持股行权的影响因素和经济后果,丰富了中小投资者保护的相关研究,对相关政策制定者未来的政策研究与制定提供参考.     

信息视角下基于异质信念的股票波动性价值研究

 经典金融学理论通常将波动性视为构成股票流动性价值的因素之一,认为股票价格波动会为市场参与者带来风险,却鲜少将其作为独立的影响因素引入资产定价模型,关于波动在股票价格及收益行为中的作用可能具有风险和价值双重属性的研究尚不充分。        基于市场参与者异质性假设,区别价值型参与者和市场型参与者;基于信息视角,区别知情交易者和噪音交易者;运用无套利原理和期权博弈思想,建立信息视角下基于异质信念的股票波动性价值模型。采用最小二乘蒙特卡罗模拟和海萨尼转换对模型进行求解,分析信息不完全或不对称条件下,股票波动性价值的分布特征,讨论现金红利率水平、波动率水平、信息不对称程度和时间参数等对股票波动性价值的影响。        研究结果表明,决定股票波动性价值的首要因素是信息不对称程度,信息水平的差异能显著放大现金红利率、波动率、时间参数等对股票波动性价值的作用,提升股票波动性价值在股票价格构成中的贡献,甚至改变市场参与者的偏好和信念,实现其在市场型与价值型之间的转化。但不完全但对称的信息条件却只能对股票波动性价值起到抵减和干扰作用。此外,信息优势能使市场参与者对波动率水平的变化更加敏感,单位波动率水平变化导致的股票波动性价值变化更大;无论信息条件如何,股票波动性价值都随着现金红利率水平的提高而下降;无论波动表现为价值还是风险,股票波动性价值的绝对值都随时间参数的增大而增大。        研究结果从理论角度解释信息水平及其状态对股票价格行为的影响,分析了股票波动性价值的作用机制及表现形式,进一步完善了现代资产定价理论;实践中,不仅能为监管部门进一步完善制度建设、强化信息监管、规范上市公司信息披露行为等政策措施提供理论依据,还能帮助市场参与者深入认识股票价格的形成过程,了解市场的微观结构特征,进而提高投资决策效率,规避风险。     

Introduction to Special Section on Sensitivity Analysis and Summary of NCSU/USDA Workshop on Sensitivity Analysis

This guest editorial is a summary of the NCSU/USDA Workshop on Sensitivity Analysis held June 11–12, 2001 at North Carolina State University and sponsored by the U.S. Department of Agriculture's Office of Risk Assessment and Cost Benefit Analysis. The objective of the workshop was to learn across disciplines in identifying, evaluating, and recommending sensitivity analysis methods and practices for application to food‐safety process risk models. The workshop included presentations regarding the Hazard Assessment and Critical Control Points (HACCP) framework used in food‐safety risk assessment, a survey of sensitivity analysis methods, invited white papers on sensitivity analysis, and invited case studies regarding risk assessment of microbial pathogens in food. Based on the sharing of interdisciplinary information represented by the presentations, the workshop participants, divided into breakout sessions, responded to three trigger questions: What are the key criteria for sensitivity analysis methods applied to food‐safety risk assessment? What sensitivity analysis methods are most promising for application to food safety and risk assessment? and What are the key needs for implementation and demonstration of such methods? The workshop produced agreement regarding key criteria for sensitivity analysis methods and the need to use two or more methods to try to obtain robust insights. Recommendations were made regarding a guideline document to assist practitioners in selecting, applying, interpreting, and reporting the results of sensitivity analysis.     

Distinguishing traumatic, vicarious and routine operational stressor exposure and attendant adverse consequences in a sample of police officers

Problems in studying occupational stress within the police service are identified and the paucity of work on operational duties as potential stressors are discussed. The present study reports the results of a factor analysis of operational stressors (N = 601 serving British police officers) that revealed three factors: exposure to death and disaster; violence and injury; sexual crime. These were demonstrated to be reliable scales and were included in logistic regression models together with a range of demographic and psychological variables. Models were applied to men and women separately, which showed there to be different predictors of the likelihood of suffering distress (measured by the General Health Questionnaire, GHQ) in terms of the officer's gender and operational role. Overall the model for women officers was better at predicting psychological distress than that for men. These findings are related to aspects of the police occupational culture. Further discussion is offered that conceptualizes police operational stressors as traumatic, routine and vicarious. Finally, some implications are drawn for the provision of stress intervention in the light of this differentiation.     

Criteria for selecting a production control philosophy

Logistic objectives constitute a compromise between having short leadtimes and a low volume of work in progress on the one hand and a high resource loading and due date obligation on the other. Miscellaneous production planning approaches offered today provide different combinations of logistic objectives for satisfying a manufacturing strategy. To combine the strength of the various approaches into a unified system, a new approach based on a dynamic and distributed production planning methodology is proposed. To customize the approach, various analyses and specifications have to be made and for that reason some important characteristics and criteria for analysing production control philosophies will be given.     

The social construction of the meaning of acute stressors: a qualitative study of the personal accounts of police officers using a stress counselling service

The police profession is one in which acute stressors are encountered more frequently than in other occupations. Using the personal accounts of 35 police officers attending an in-house stress counselling clinic, the aim of the present study was to provide a qualitative examination of how the institutional context of policing influenced the ways in which acute stressors signified to individual police officers experiencing felt distress. Using the framework of Rational Emotive Behaviour Therapy as an analytical tool, it is argued that beliefs contributing to the experience of felt distress are related to the way in which policing as both an identity and an activity is constructed through the police organizational culture. Not only do these constructions influence the ways in which officers perceive themselves and their environments, but they also operate at the collective level to 'normalize' some emotional responses and to 'pathologize' others which, it is argued, could impact upon the outcomes of interventions such as stress counselling.     

The moderating role of social support in Karasek's job strain model

This paper examines whether social support is a boundary-determining criterion in the job strain model of Karasek (1979). The particular focus is the extent to which different sources of social support, work overload and task control influence job satisfaction, depersonalization and supervisor assessments of work performance. Hypotheses are tested using prospective survey data from 80 clerical staff in a university setting. Results revealed 3-way interactions among levels of support (supervisor, co-worker, non-work), perceived task control and work overload on levels of work performance and employee adjustment (self-report). After controlling for levels of negative affect in all analyses, there was evidence that high levels of supervisor support mitigated against the negative effects of high strain jobs on levels of job satisfaction and reduced reported levels of depersonalization. Moreover, high levels of non-work support and co-worker support also mitigated against the negative effects of high strain jobs on levels of work performance. The results are discussed in terms of the importance of social support networks both at, and beyond, the work context.     

Job insecurity, coping resources and personality dispositions in occupational strain

This paper presents research on the relationships between the work-related stressor of perceived job insecurity and various indicators of occupational strain, taking into account employees' personality dispositions (trait negative and positive affectivity) and coping resources. Respondents were 222 Australian public servants surveyed during organizational restructuring that involved downsizing and threat to job certainty. The research was formulated within an adaptation of Osipow, Doty, and Spokane's (1985) framework of stress-strain-coping that included the possible direct as well as moderating effects of personality dispositions in reporting occupational strain (Parkes, 1990). Findings from hierarchical regression analyses indicate consistent significant independent effects of personality dispositions, coping resources and perceived job insecurity on various indicators of strain. There was also support for the moderating roles of negative affectivity and self-care in the relation between perceived job insecurity and physical strain. Implications for the role of dispositional factors, especially negative affectivity, and the utility of various coping resources in accounting for occupational strain in times of threatened job security are discussed.     

Job stress, job strain, and psychological withdrawal among Dutch university staff: towards a dualprocess model for the effects of occupational stress

This study examined the antecedents of job strain (emotional exhaustion, health complaints) and withdrawal behaviour (e.g. lowered organizational commitment) among a cross-sectional sample of 131 academic staff members of the law department of a large Dutch university. Conservation of resources theory (Hobfoll, 1989) provided the theoretical background for this study. Strains and withdrawal behaviours were expected to be most prominent among those who reported having few resources and/or who reported high job demands. Structural equation modelling revealed that this was indeed the case. As predicted, differential patterns of effects emerged for job demands and job resources. Analysis of the effects of four job-specific stressors revealed that especially the structural aspects of a staff member's teaching task (e.g. the number of students in their classes) contributed strongly to perceived job demands. Theoretical and practical implications of the study are discussed.     

Dermal Uptake of 18 Dilute Aqueous Chemicals: In Vivo Disappearance‐Method Measures Greatly Exceed In Vitro‐Based Predictions

Average rates of total dermal uptake (K_up) from short‐term (e.g., bathing) contact with dilute aqueous organic chemicals (DAOCs) are typically estimated from steady‐state in vitro diffusion‐cell measures of chemical permeability (K_p) through skin into receptor solution. Widely used (“PCR‐vitro”) methods estimate K_up by applying diffusion theory to increase K_p predictions made by a physico‐chemical regression (PCR) model that was fit to a large set of K_p measures. Here, K_up predictions for 18 DAOCs made by three PCR‐vitro models (EPA, NIOSH, and MH) were compared to previous in vivo measures obtained by methods unlikely to underestimate K_up. A new PCR model fit to all 18 measures is accurate to within approximately threefold (r = 0.91, p < 10^?5), but the PCR‐vitro predictions (r > 0.63) all tend to underestimate the K_up measures by mean factors (UF, and p value for testing UF = 1) of 10 (EPA, p < 10^?6), 11 (NIOSH, p < 10^?8), and 6.2 (MH, p = 0.018). For all three PCR‐vitro models, log(UF) correlates negatively with molecular weight (r² = 0.31 to 0.84, p = 0.017 to < 10^?6) but not with log(vapor pressure) as an additional predictor (p > 0.05), so vapor pressure appears not to explain the significant in vivo/PCR‐vitro discrepancy. Until this discrepancy is explained, careful in vivo measures of K_up should be obtained for more chemicals, the expanded in vivo database should be compared to in vitro‐based predictions, and in vivo data should be considered in assessing aqueous dermal exposure and its uncertainty.     

Systems Resilience for Multihazard Environments: Definition,Metrics, and Valuation for Decision Making

The United Nations Office for Disaster Risk Reduction reported that the 2011 natural disasters, including the earthquake and tsunami that struck Japan, resulted in $366 billion in direct damages and 29,782 fatalities worldwide. Storms and floods accounted for up to 70% of the 302 natural disasters worldwide in 2011, with earthquakes producing the greatest number of fatalities. Average annual losses in the United States amount to about $55 billion. Enhancing community and system resilience could lead to massive savings through risk reduction and expeditious recovery. The rational management of such reduction and recovery is facilitated by an appropriate definition of resilience and associated metrics. In this article, a resilience definition is provided that meets a set of requirements with clear relationships to the metrics of the relevant abstract notions of reliability and risk. Those metrics also meet logically consistent requirements drawn from measure theory, and provide a sound basis for the development of effective decision‐making tools for multihazard environments. Improving the resiliency of a system to meet target levels requires the examination of system enhancement alternatives in economic terms, within a decision‐making framework. Relevant decision analysis methods would typically require the examination of resilience based on its valuation by society at large. The article provides methods for valuation and benefit‐cost analysis based on concepts from risk analysis and management.     

Employees' perceptions of organizational restructuring: the role of social support

Organizational change and restructuring is often perceived as leading to increased occupational stress, impacting negatively on the psychological well-being of employees. This pragmatic study investigates the role of social support and dispositional affect as moderators of role stress post-restructuring for employees in a public utility company. A total of 176 employees, including 37 managers, 60 graded staff and 78 industrial staff completed a self-report questionnaire, approximately 1 year postrestructuring, retrospectively assessing role conflict, ambiguity, overload and positive and negative feedback pre- and post-restructuring. Results suggested that overall role stress increased for managers/ senior officers and graded staff, but not for industrial staff. Social support was linked with lower role stress, more positive feedback and less negative feedback at post-restructuring. For certain role stressors this impact was moderated by dispositional affect, but the effect was not consistent across occupational groups. Positive affect enhanced the effect of manager support in reducing role conflict for graded staff, and the effect of co-worker support in increasing positive feedback and reducing negative feedback for industrial staff. Findings suggest that managers should pay particular attention to support and feedback for employees during periods of chronic occupational stress following organizational restructuring.