正态分布下期货套期保值CVaR风险的敏感度

条件风险价值(Conditional Value-at-Risk,CVaR)是比风险价值更优越的风险计量技术.本文把条件风险价值应用于期货套期保值,分析期货套期保值条件风险价值的敏感性.在正态分布下,分空头期货套期保值和多头期货套期保值两种情况,导出期货套期保值条件风险价值关于期货头寸的一阶、二阶变化率,并解释其经济意义.为套期保值者在期货套期保值中根据条件风险价值的敏感度增减期货头寸提供指导.     

中国商品期货市场风险溢价及其影响因素测度研究:基于套期保值压力效应的视角

本文基于套期保值压力效应的视角主要从商品期货合约本身的套期保值压力和交叉套期保值压力两个方面对我国农产品、能源化工和金属商品期货的风险溢价进行测度和分析.实证研究表明:当控制系统风险后,商品期货本身的套期保值压力与存在于组内的交叉套期保值压力均显著地影响期货的风险溢价.最后,本文引入价格压力变量以检验期货风险溢价模型的稳健性,当控制价格压力后,这两种套期保值压力效应仍然显著地存在.     

基于动态规划多期期货套期保值优化模型研究

通过对套期保值者头寸价值变化量的分析,采用动态规划方法,建立了多期套期保值动态模型,推导出多期套期保值进行动态跟踪调整的策略。该模型的特点一是反映了期货交易费用在套期保值中的作用,解决了现有期货套期保值策略忽略交易费用的不足,提高了模型的准确性。二是考虑保证金对期货套期保值的影响。把期货交易保证金的机会损失纳入套期保值策略内,从而使套期保值直接反映了期货保证金无利息收入、而存在机会成本的真实情况,弥补了现有研究不考虑期货交易保证金的机会损失的缺陷。三是体现了套期保值者收益最大化的原则。解决了现有模型只考虑了规避期货和现货组合的价格波动风险,忽略组合的收益的弊端,增加了模型的实用性和适用性。     

商品期货套期保值的会计处理实例探析

针对近年来金属价格高位运行且剧烈波动的形势,许多以贵金属为主要原材料的加工企业,都积极运用商品期货合约,采用各种套期保值策略,以规避经营风险,由此涉及商品期货套期保值的会计实务处理问题.本文通过企业商品期货合约套期保值实施的具体案例,对套期保值会计实务处理有关问题进行分析和探讨.     

利用扩展基尼均值系数计算股指期货套期保值比率

本文在Yitzhaki利用基尼均值系数计算金融期货套期保值比率的基础上,提出了利用扩展基尼均值系数来计算股指期货最优套期保值比率,并通过公式推导证明,Yitzhaki的基尼均值系数,仅是扩展基尼均值套期保值比率的特殊情况。     

股指期货套期保值模型发展的比较评述

运用股指期货套期保值的理论和实践是随着套期保值模型的改进而不断发展的。本文在总结OLS、VAR及VECM等静态套期保值模型的基础上,介绍了二元广义自回归条件异方差(B-GARCH)模型、卡尔曼滤波(Kal- man filter)以及马尔可夫状态转换(Markov regime switching)等模型在套期保值中的应用。从理论上解释了动态模型改进套期保值绩效的原因,为国内投资者运用股指期货进行套期保值提供了模型选择的建议。     

基于Mean-CVaR约束的股指期货动态套期保值模型研究

本文建立了基于最小化均值-条件风险价值( Mean-CVaR)的股指期货动态套期保值模型.模型的主要特点与贡献在于两方面:一方面,考察了置信水平和可变交易费用对最优套期保值决策的影响;另一方面,利用二元误差修正的时变条件相关GARCH模型估计套期保值比率,优点是不仅考虑了股指期货与现货价格序列之间存在的协整关系,而且更好地拟合了收益残差序列存在的异方差性与相关系数时变性的特征.最后通过对我国沪深300指数期货仿真交易的套期保值模拟与实证测算,得出能够动态调整的股指期货套期保值策略以实时追踪与控制风险.     

规避逐日盯市风险的期货套期保值模型

将规避逐日盯市风险引入到期货套期保值模型的研究中。给出规避逐日盯市风险的约束条件,建立自有资金情况下考虑规避现货价格风险和逐日盯市风险的期货套期保值模型,并采用图解方法给出该情况下的最优套期保值比率的解析式,研究自有资金不足、需要借入资金情况下应该如何选择最优的套期保值比率,以获得最佳的套期保值效果,以上海期货交易所期铜的套期保值为例,说明逐日盯市风险对于套期保值的影响以及模型的适用性。研究结果表明,在套期保值资金有限的情况下,如果不考虑保证金制度和逐日盯市制度的施行对于套期保值的影响,传统的方差最小方法很可能会出现保证金不足的情况,从而面临强行平仓的风险,而本模型可以规避这种风险。     

基于EMD的螺纹钢期货套期保值功能研究

本文运用经验模态分解(EMD)方法对螺纹钢期货和现货价格的对数收益率数据进行分解.通过对不同周期的分量进行对比,本文研究了套期保值期限与最优套期保值比率和套期保值绩效之间的关系.实证结果表明:随着套保期限的增加,最优套期保值比率先增大,后减小;螺纹钢市场进行不同期限的套期保值能够不同程度地降低螺纹钢现货生产和经营的风险,短期套期保值的效果更好.     

基于时变Markov的DCC-GARCH模型最小风险套期保值研究

考虑Markov状态转移概率的时变特征,在传统DCC-GARCH基础上,提出基于Markov时变转移概率的DCC-GARCH模型（TVTP-DCC-GARCH）研究最小风险套期保值比例的估计方法,并利用两阶段极大似然法对模型参数进行估计。进一步分别从样本内和样本外估计沪深300指数期货和现货的最优套期保值比率,对套期保值的绩效进行检验,并将检验结果分别与Markov转移概率恒定的DCC-GARCH（FTP-DCC-GARCH）、DCC-GARCH、OLS、1：1完全套期保值以及无套期保值的沪深300指数现货的绩效进行对比。实证结果表明,利用基于Markov状态转移的DCC-GARCH模型研究沪深300指数期货的套期保值问题具有一定合理性,且在参数估计中TVTP-DCC-GARCH模型的拟合效果最佳;在套期保值有效性方面,TVTP-DCC-GARCH模型优于其他模型,说明在DCC-GARCH模型中引入时变状态转移概率能够有效提高套期保值组合的绩效。     

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.