基于随机折现因子方法的流动性定价机制研究

流动性影响股票收益的渠道在文献中需进一步厘清,本文采用随机折现因子的方法构建了SDF-LCAPM模型,将流动性影响股票收益的渠道分为两个:第一个渠道是股票自身的流动性特征直接影响股票收益;第二个渠道为流动性是系统风险的组成部分,影响股票的收益。SDF-LCAPM模型提供了联接两个渠道的框架,解开了流动性的波动性与资产收益负向关系之谜,解释了系统流动性与股票收益率对市场流动性的敏感度不被定价的可能原因,还发现了流动性与资产收益的协方差在资产定价中的重要作用。本文通过实证发现,这两个渠道在不同类型股票中的表现是不同的,这一发现为投资者流动性风险管理提供参考依据。此外,SDF-LCAPM模型应用在中国股票市场上,可以提高投资组合的Sharpe比率。     

涨跌幅限制对股票流动性的影响分析

针对涨跌幅限制对股票流动性的影响存在不同的观点,实证研究了沪市的涨跌幅限制对股票流动性的影响.结果表明,无论采用传统流动性度量方法(交易股数和换手率)还是基于波动性的流动性度量方法,涨跌幅限制约束了股票当天的流动性,致使在以后的几个交易日股票的流动性优于其它股票,即涨跌幅限制存在流动性干扰效应.通过对3种流动性度量方法的有效性比较分析,得出基于波动性的流动性度量方法更适合度量沪市股票的流动性.     

行业股票价格指数波动特征的实证研究

行业风险是投资者进行投资决策、选择行业时要考虑的主要因素之一。行业股票价格指数的波动性常用来衡量行业的风险。本文采用四种具有代表性的衡量波动性的指标来研究行业股票指数的波动特征,将总风险量化分解为与市场相关的风险和行业特有的风险两部分,对各行业的风险特征进行深入分析。实证研究采用深交所依据《上市公司行业分类指引》所编制的行业指数数据,分阶段估计股票行业指数的波动性,并进行Kendall协同系数检验。结果表明,不同阶段的行业总体波动性和行业特有的波动性排序间存在一致性,即行业间的波动性大小次序相对稳定,但在与市场相关的波动性排序上不具有稳定性。本文的结论刻画了中国股票市场行业股票指数间的波动性特征,与国际上的相关研究成果具有可比性,对资产在行业间的配置等投资策略问题的研究有参考价值。     

中国股市中信息反应模式的实证分析

本文在Hong和Stein(1999)信息扩散假说的基础上,集中研究中国股票市场中的短期反应不足和过度反应。实证结果表明中国股票市场对不同类型的信息有不同的反应方式。对于影响所有股票的收益率的宏观经济变化、行业相关政策变动等市场共同信息,股票的收益率存在过度反应现象;对于公司层面上的个股特定信息,股票的收益率存在明显反应不足。同时投资者对正面信息与负面信息的反应模式也有截然的区别,投资者对正面市场信息(利好)存在明显的过度反应,故在市场利好信息到达时,采用反向策略更为有利;由于投资者惜售的“处置效应”的影响,导致对市场利空信息的反应不足,在较短期内尤为明显。     

中国股票市场短期反转效应的流动性供给解释——机构投资者退出的角度

本文基于中国沪深股市2001年1月～2016年7月的相关数据,从机构投资者是市场流动性的供给方、活跃的机构投资者对个股持股比例的增加或减少影响个股的市场流动性的角度对中国股票市场短期反转效应予以研究。相关研究结论表明未预期的流动性供给变化是中国股票市场短期反转效应的原因,反转策略收益是对未预期流动性供给冲击的风险补偿,而未预期的机构投资者的参与或退出是影响股票市场流动性供给的来源。此外本文研究还表明中国股票市场存在显著的短期反转效应,且短期反转效应的强度大小与投资组合的选择有关。     

股票流动性风险测度模型的构建与实证分析

传统度量流动性风险的方法是计算股票的平均流动性水平,近年来逐渐考虑到了流动性的波动性,对流动性风险的度量更加接近实际.本文在以上两种衡量流动性风险方法的基础上建立了包含"横"与"纵"两维上的新的流动性风险测度模型--流动性"成本-风险"矩形和等流动性风险曲线,并以上海证券交易所上市的107只A股为样本进行实证检验,结果表明该模型能够比较全面真实的测度股票的流动性风险.     

定单流、流动性与股票市场的投资转移

本文通过分析我国股票市场上市值不同的股票之间定单流、流动性和收益率的相互影响关系,以及它们与上海银行间同业拆借利率(CHIBOR)、人民币远期汇率的关系,讨论了市场内不同股票之间的投资转移行为。实证结论发现:低市值股票定单流上升时,未来高市值股票流动性和收益率显著下降,市值不同的股票之间流动性和收益率也表现出显著的双向、负向领先滞后关系;银行间拆借利率、人民币汇率等影响宏观(货币)流动性的因素将显著影响市场微观流动性、定单流和收益率,但对市值不同的股票有不同的影响。本文提供了不同市值股票之间存在投资转移行为的证据。     

中国股市流动性溢价的实证研究

本文根据股票市场流动性溢价理论，采用换手率(TURN)和非流动性(ILLIQ)两个指标，对上海股票市场的流动性与预期收益的关系分个股数据和组合数据进行实证研究，同时研究两者关系的影响因素。研究结果表明：对于个股数据，换手率对预期收益具有负向作用，非流动性对预期收益具有正向作用，支持流动性溢价理论；此外，在不同市场态势、有无政策或重大事件和基于组合数据分析的情况下，换手率与预期收益之间仍然保持显著的负向关系，而ILLIQ与预期收益之间的关系不稳定或呈现相反结果。由此可见，我国股票市场的流动性与预期收益的关系受流动性度量、市场态势、政策或重大事件和估计的数据构造的影响。     

股票流动性能够解释收益反转之谜吗?

以我国沪深股票市场为例研究了股票收益率反转与股票流动性的关系,以期为股票收益率反转和股票流动性之间关系明确前提条件,提供不同国家金融市场差异性研究的佐证.研究表明我国沪深A股市场存在着显著的反转效应与流动性溢价效应;然而与针对美国市场的理论解释相悖,发现股票收益的反转与股票流动性之间代表了我国沪深A股市场上的两种截然不同的风险因素,股票的流动性因素并不完全是股票收益反转的潜在解释因素.并进一步通过分析得出操纵股票行为可能导致这种流动性解释在我国沪深股市上并不适用,这种操纵股票行为本身直接就会导致我国沪深股市短期收益反转.     

上海证券市场流动性模式的研究

本文运用高频数据对上海股票市场流动性的日内和周内变化模式进行了实证研究,同时从市场微观结构理论出发分析了这种流动性模式的形成原因。在此基础上,建立了回归模型,实证研究了影响上海股市流动性的影响因素,结果表明上海股市流动性确实存在着明显的周内和日内变化模式,从而揭示了我国股票市场在流动性方面的微观结构特征。     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

UNIX系统性能监控简述及shell系统资源统计程序

本文简要阐述了unix系统中(主要以IBM的AIX为例)进行系统性能管理的几种命令行工具,并通过编写shell实例程序,运用其中提到的工具实现系统资源利用率的统计程序,为做好unix系统管理和调优提供参考.