随机跳跃强度与期权隐含风险溢酬北大核心CSCDCSSCI

基于随机波动率随机跳跃强度(SVSJ)的期权定价模型,从时间序列性质与横截面期权定价两个角度对长达12年的S&P 500指数期权数据进行了研究.实证结果发现:只有短期虚值期权与短期平值期权中存在显著的跳跃风险溢酬,并且跳跃风险溢酬远超过波动率风险溢酬.不同模型不同跳跃强度的设定都可以估计出显著的跳跃风险溢酬,虽然跳跃风险的方差在总风险的方差中所占比例较低,但跳跃风险溢酬在总风险溢酬中所占的比例却大得多.各模型在高波动时期的表现都要优于低波动时期,其中SVSJ模型在所有模型中表现最好.     

自刺激跳跃与随机波动率交叉反馈下的期权定价

构建合理的资产价格模型一直都是期权定价研究的核心问题之一,其中波动率和跳跃又是资产价格模型中的重要研究对象。已有实证研究发现资产价格存在跳跃聚集现象,该现象在金融危机期间尤为明显;同时,资产价格的波动率也存在跳跃,且资产价格的跳跃与波动率之间还存在非对称的交叉反馈作用。因此,将上述特征纳入期权定价模型中,有助于提高模型的期权定价性能,且能使模型更准确地估计隐含波动率。为了刻画资产价格的跳跃聚集、波动率跳跃以及跳跃与波动率之间的非对称交叉反馈特征,在仿射跳扩散框架下,构建用于期权定价的自刺激跳跃与随机波动率交叉反馈模型,并利用风险中性定价、广义傅里叶变换和条件特征函数,求出欧式期权价格的半解析表达式。采用上证50ETF期权数据对模型进行校准,并对比分析模型对期权价格以及隐含波动率的拟合和预测能力。研究结果表明,上证50ETF的价格与其波动率呈负相关,呈现杠杆效应和负向的波动率反馈效应,价格存在上跳和下跳聚集,价格的波动率与跳跃之间存在非对称的交叉反馈作用,下跳对波动率的影响大于上跳对波动率的影响,而波动率对下跳强度的影响大于其对上跳强度的影响,该特征能很好地解释股灾期间股价崩盘现象。无论...     

基于已实现波动率的50ETF期权定价研究

  2015年2月9日上证50ETF期权正式上市交易,标志着中国开始进入期权时代,也对期权的准确定价提出了迫切要求。波动率是期权定价模型的核心参数,准确估计和有效预测波动率对期权定价性能至关重要。         利用50ETF的日内高频价格计算已实现波动率,使不可观测的波动率可以直接估计和建模。对已实现波动率构建带杠杆的异质自回归伽马(HARGL)模型,以及带异质杠杆的异质自回归伽马(HARGHL)模型。提出进一步区分日内价格上行、下行风险对已实现波动率预测的贡献,引入利用日内正、负高频收益率计算的已实现正、负半差,将上述模型分别改进为HARGL-S模型和HARGHL-S模型,以更好地刻画波动的日内杠杆效应。通过对参数估计从真实测量到风险中性测量的转换,实现蒙特卡洛模拟法的期权定价。采用50ETF期权上市起至2017年4月18日的42 406条期权合约收盘价数据,通过模拟在期权价格和隐含波动率上的均方根误差,比较4种模型的定价性能。         研究结果表明,①50ETF看涨期权和看跌期权均表现出明显的波动率“微笑”特征;②中国股市波动的风险溢酬显著为正,有必要对波动率模型参数估计进行从真实测量到风险中性测度的转换;③已实现正、负半差和异质杠杆的引入都能够显著提高模型的期权定价能力,同时引入则模型定价能力总体最优;④引入已实现正、负半差对非深度实值超短期、短期看涨期权的定价性能改善最为明显,引入异质杠杆对非深度实值超短期、短期看跌期权的定价性能改善最为明显。         研究结论拓展了对50ETF期权定价的方法,肯定了在已实现波动率异质自回归伽马模型中引入已实现正、负半差和异质杠杆的重要价值,对于投资者进行有效的期权定价和交易以及监管机构进行有效的决策具有实际指导意义。     

跳跃风险如何影响期权复制收益?——基于多维跳跃扩散的模型与证据

文章在最一般的多维跳跃扩散过程假设下,推导出Delta对冲组合盈亏所遵循的随机过程,从理论上证明了Delta对冲组合会受到跳跃风险以及跳跃风险的风险溢酬的影响.并且,通过美国SPX期权数据对理论推导的结论进行分样本实证,实证结果表明,在考虑了模型风险、市场信息传递效率等以往学者未曾考虑到的控制变量后,跳跃风险对于对冲标的风险后的期权复制收益的影响仍然显著,但其影响看涨看跌期权的内在途径和机理在平时、危机时刻都不相同.     

支持向量回归方法的跳跃扩散汇率期权定价

本文构建一种新的汇率期权定价模型.采用基于统计学习理论通用学习方法支持向量回归技术,引入跳跃扩散模型捕获汇率市场动态过程的跳跃,以提高汇率期权价格预测效果.新模型采用模型参考结构,结合了参数方法与非参数方法各自的优势.SVR技术中用SV模型估计汇率市场的波动率,作为支持向量回归的输入值.实证表明新的汇率期权定价模型的预测效果明显好于传统汇率期权定价方法.     

跳自刺激效应下的VIX期权定价研究

针对VIX指数的均值回复、波动率聚集特征以及实证研究最近发现的跳跃自刺激性,本文采用具有自刺激性的Hawkes过程对VIX指数的跳跃进行建模,进而构建仿射跳跃扩散模型用于VIX期权定价,得到Hawkes跳跃扩散过程的条件特征函数,然后在风险中性定价框架内采用傅里叶变换方法推导出VIX期权的价值表达式。实证结果表明,本文模型不仅能克服一般均值回复模型拟合误差大的缺点,且能产生正的隐含波动率倾斜和隐含波动率微笑;另一方面,由于考虑了跳跃的自刺激,本文模型在泊松跳跃均值回复模型基础上进一步改善了VIX期权价格的预测效果。     

Lévy 过程驱动非高斯 OU 随机波动率下的期权定价

考虑金融时间序列发生的跳跃、随机波动率和“杠杆效应”, 建立由不同Lévy过程驱动的非高斯OU随机波动模型.通过结构保持等价鞅测度变换和FFT技术, 对不同Lévy过程驱动下的非高斯OU (non-Gaussian Ornstein-Uhlenbeck process) 期权定价问题进行研究.同时, 在结构保持等价鞅测度下, 推导出不同Lévy过程驱动下BNS模型离散化表达形式, 并构建了基于SMC (sequential Monte Carlo) 的极大似然估计、联合样本估计、梯度-SMC估计的非高斯OU期权定价模型参数估计方法.实证研究中, 采用近470万个S&P500期权价格数据, 从样本内拟合效果、样本外预测、模型稳定性、综合矫正风险几个方面, 对不同Lévy过程驱动的非高斯OU期权定价模型、参数估计方法以及期权定价效果进行全面系统研究.实证研究表明, 所有模型对实值期权的定价效果要优于虚值期权.本文基于联合样本估计和梯度-SMC估计的非高斯OU期权定价模型具有明显的优势.     

一类高新技术企业专利权价值的实物期权评估方法——基于跳扩散过程和随机波动率的美式期权的建模与模拟

由于经典的Black-Scholes期权定价模型的假设忽略了突发事件对资产价格的影响和"波动率微笑"对期权价值的影响而与实际情形往往存在偏差,因此学者们对Black-Scholes模型的改进则主要分别集中在带跳扩散过程的期权定价模型与具随机波动率的期权定价模型等两个方面,然而却少见将这两种模型结合起来的研究。本文首先在带跳扩散过程的期权定价模型与具随机波动率的期权定价模型的研究工作的基础上,建立了一种同时带跳扩散过程和具随机波动率的美式期权定价模型,并通过伊藤引理推导出了资产价格、随机波动率和期权满足的偏微分方程;然后,利用特征函数法和傅里叶变换导出了资产价格的随机分布,进而通过马尔科夫链方法给出了基于跳扩散过程和随机波动率的美式期权的数值解;最后,运用已建立的带跳扩散过程和随机波动率的美式期权定价模型对高新技术企业项目投资的专利权价值进行实物期权定价评估的案例研究,并对跳扩散强度参数和随机波动率参数进行敏感性分析,研究结果表明:将项目收益跳扩散过程和市场环境随机波动率加入到专利权实物期权定价模型中,可以有效避免专利权的期权价值被高估。     

随机波动HJM框架下可违约债券市场波动结构的实证研究

波动结构对于可违约债券及其衍生品的定价和风险管理具有重要意义.利用AAA级企业债券价格数据,基于中国可违约债券市场构建三因子可违约随机波动HJM模型,并对其进行有限维马尔科夫仿射实现.在此基础上,从波动因子的随机波动特征、相关性结构和贡献度3个方面对中国可违约债券市场的波动结构进行系统分析.研究结果表明,样本期内中国可违约债券隐含的无风险利率和信用利差的波动率中含有显著的随机波动过程,且其数值呈现持续增大的趋势;无风险短期利率、短期信用利差和随机波动过程3个主要波动因子之间存在显著的相关关系;各波动因子的风险贡献度随时间推移而发生明显的波动.在经济向好时期,无风险短期利率的风险贡献较大;在经济趋冷时期,短期信用利差的风险贡献占优.     

时变风险厌恶下的期权定价——基于上证50ETF期权的实证研究

传统的随机波动率（SV）期权定价是在投资者具有常数风险偏好假设下进行的.但近年来越来越多的研究表明,市场参与者具有时变风险厌恶特征.基于此,本文对时变风险厌恶条件下的期权定价问题进行深入研究.首先,对传统的（非仿射）常数风险厌恶SV（CRA-SV）期权定价模型进行扩展,构建时变风险厌恶SV（TVRA-SV）期权定价模型对期权进行定价,并分析时变风险厌恶对期权价格的影响;其次,采用标的资产与期权数据信息,建立基于连续粒子滤波的极大似然估计方法,对定价模型的客观与风险中性参数进行联合估计;最后,采用我国期权市场上的上证50ETF期权数据,对构建的定价模型进行实证检验.结果表明：TVRA-SV期权定价模型相比传统的CRA-SV期权定价模型具有更好的数据拟合效果,能够更充分地刻画标的上证50ETF收益率在客观与风险中性测度下的波动性;TVRA-SV期权定价模型相比传统的Black-Scholes（B-S）期权定价模型和CRA-SV期权定价模型都具有明显更高的定价精确性。     

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.     

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.     

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.     

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.     

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.