时变最优套期保值比估计及比较研究——基于卡尔曼滤波在状态空间模型中的应用

运用状态空间模型并基于卡尔曼滤波方法对中国铜期货市场时变最优套期保值比进行估计.对OLS、VAR、VECM、CC GARCH及SSPACE等模型的套期保值效率进行了比较.套期保值效率分别用方差下降百分比和夏普比下降百分比来测度.两种测度方法都表明,基于卡尔曼滤波的状态空间模型明显优于其他模型.该结论对于套期保值期限是稳定的.GARCH模型并不确定优于非时变模型.非时变模型中,VECM模型的表现最差.而VAR模型也并不明显优于简单的OLS模型.计量经济模型预测总风险由模型(误设)风险和估计风险构成.高级计量经济模型的模型(误设)风险较小,估计风险增大,总效应则不确定.卡尔曼滤波获得贝叶斯规则最优解,因而在处理估计风险方面较其他模型占优.     

基于MCMC模拟的期货最优套保比贝叶斯分析

计量经济模型总风险由模型(误设)风险和估计风险构成.本文同时运用基于频率统计的后视计量经济模型和基于McMC模拟的贝叶斯方法对我国铜期货市场不同套期保值期限的最优套期保值比进行实证分析.实证结果清楚表明,估计风险对模型结果有重要影响.在处理估计风险方面,贝叶斯方法较频率统计方法有明显优势.另外,套期保值效率与套期保值期限之间的正相关关系在本研究中得到确定,无论是基于频率统计,还是基于贝叶斯统计.     

运用沪铜期货有效化解市场价格风险的研究——基于套期保值模型的比较选择分析

面对国内外复杂的市场经济形势,我国把防范化解经济领域重大风险放在新时代国家建设的重要战略位置。企业防范化解市场价格风险的重要手段之一是开展套期保值业务。该文基于沪铜期货套期保值功能,分别采用静态模型OLS、B-VAR、VECM和动态模型ECM-GARCH进行套期保值比率的估计及比较。实证结果表明,4种模型均能有效降低套保组合风险,其中动态ECM-GARCH模型的套期保值效果最优,能使企业有效规避56.32%的价格风险,从而增强我国企业套期保值的风险管理应用效果,提升金融服务实体经济能力。     

套期保值, 估计风险与贝叶斯统计——基于中国铜期货市场的经验研究

针对期货最优套期保值策略估计中可能存在的估计风险问题,本文对单变量线性回归模型(OLS模型)和多变量线性回归模型(VAR模型和EC-VAR模型)进行贝叶斯分析,并采用Gibbs抽样方法对中国铜期货市场的最优套期保值策略进行了实证分析。本文还同时估计了基于频率统计方法的最优套期保值策略,并对贝叶斯统计下和频率统计下的最优套期保值策略进行了分析比较。实证结果清楚表明,估计风险对模型结果有重要影响。在处理估计风险方面,贝叶斯统计较频率统计方法有明显优势。     

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.     

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.     

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.     

基于M-Copula-GJR-VaR模型的黄金市场最优套期保值比率研究

基于VaR的风险测度方法既侧重收益的负向波动风险,又可通过置信水平的设定满足有不同风险偏好的投资者的需求.以具有金融和商品双重属性的黄金为实证对象,充分考虑现货和期货市场的非对称性、两者之间的协整关系以及非线性相关的特征,以风险最小化为原则,建立M-Copula-GJR-VaR动态套期保值比率估计模型.采用中国市场现货价格和期货价格数据,对比分析M-Copula-GJR-VaR模型与CCC-GARCH-VaR模型、DCC-GARCH-VaR模型、Clayton Copula-GJR-VaR模型和Gumbel Copula-GJR-VaR模型的套期保值比率和套期保值效果.研究结果表明,经过4年多的发展,套期保值效率处于0.672～0.704之间的中国黄金期货市场还不成熟,套期保值功能的发挥有待提高;采用M-Copula-GJR-VaR模型估计的套期保值比率最优且套期保值效果最好,应用该模型进行黄金市场套期保值操作,可达到以相对较少的套期保值成本较大程度地规避现货市场价格风险的目的.     

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。     

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。     

Trust,Emotion, Sex,Politics, and Science: Surveying the Risk-Assessment Battlefield

Risk management has become increasingly politicized and contentious. Polarized views, controversy, and conflict have become pervasive. Research has begun to provide a new perspective on this problem by demonstrating the complexity of the concept risk and the inadequacies of the traditional view of risk assessment as a purely scientific enterprise. This paper argues that danger is real, but risk is socially constructed. Risk assessment is inherently subjective and represents a blending of science and judgment with important psychological, social, cultural, and political factors. In addition, our social and democratic institutions, remarkable as they are in many respects, breed distrust in the risk arena. Whoever controls the definition of risk controls the rational solution to the problem at hand. If risk is defined one way, then one option will rise to the top as the most cost-effective or the safest or the best. If it is defined another way, perhaps incorporating qualitative characteristics and other contextual factors, one will likely get a different ordering of action solutions. Defining risk is thus an exercise in power. Scientific literacy and public education are important, but they are not central to risk controversies. The public is not irrational. Their judgments about risk are influenced by emotion and affect in a way that is both simple and sophisticated. The same holds true for scientists. Public views are also influenced by worldviews, ideologies, and values; so are scientists' views, particularly when they are working at the limits of their expertise. The limitations of risk science, the importance and difficulty of maintaining trust, and the complex, sociopolitical nature of risk point to the need for a new approach—one that focuses upon introducing more public participation into both risk assessment and risk decision making in order to make the decision process more democratic, improve the relevance and quality of technical analysis, and increase the legitimacy and public acceptance of the resulting decisions.     

Why Study Risk Perception?

Studies of risk perception examine the opinions people express when they are asked, in various ways, to characterize and evaluate hazardous activities and technologies. This research aims to aid risk analysis and societal decision making by (i) improving methods for eliciting opinions about risk, (ii) providing a basis for understanding and anticipating public responses to hazards, and (iii) improving the communication of risk information among laypeople, technical experts, and policy makers.     

Taxonomic Analysis of Perceived Risk: Modeling Individual and Group Perceptions Within Homogeneous Hazard Domains

Previous studies of risk perception have typically focused on the mean judgments of a group of people regarding the riskiness (or safety) of a diverse set of hazardous activities, substances, and technologies. This paper reports the results of two studies that take a different path. Study 1 investigated whether models within a single technological domain were similar to previous models based on group means and diverse hazards. Study 2 created a group taxonomy of perceived risk for only one technological domain, railroads, and examined whether the structure of that taxonomy corresponded with taxonomies derived from prior studies of diverse hazards. Results from Study 1 indicated that the importance of various risk characteristics in determining perceived risk differed across individuals and across hazards, but not so much as to invalidate the results of earlier studies based on group means and diverse hazards. In Study 2, the detailed analysis of railroad hazards produced a structure that had both important similarities to, and dissimilarities from, the structure obtained in prior research with diverse hazard domains. The data also indicated that railroad hazards are really quite diverse, with some approaching nuclear reactors in their perceived seriousness. These results suggest that information about the diversity of perceptions within a single domain of hazards could provide valuable input to risk-management decisions.     

相关性下的银行风险集成研究综述

银行风险之间的相关关系会使风险之间相互转化，相互影响，令风险呈现出放大或者缩小的趋势，显著影响着银行风险度量结果的准确性。银行风险集成致力于在充分考虑银行风险相关关系的基础上，对银行风险进行较为准确的度量。但是银行风险具有相关关系种类繁多、表现形式复杂、以及数据的可获得性差等显著特征，导致银行风险的集成度量领域存在诸多挑战。本文对相关性下的银行风险集成研究进行综述，具体从集成对象、集成方法和集成数据三个层次系统展开。首先对银行风险及其蕴含的种类繁多的相关关系类型进行解析，然后分析银行风险相关关系表征出的多种复杂特性，根据对这些特性的刻画能力对银行风险的集成方法进行划分和比较，最后总结了获取银行风险集成数据的多种途径。在此基础上，进一步分析了银行风险集成研究的难点和未来趋势。     

The Theory of Risk Homeostasis: Implications for Safety and Health

No strategy for countermeasure design or future directions of research in the areas of human behavior which leads to traffic accidents or lifestyle-related diseases can be rationally developed without an acceptable working theory of human behavior in these domains. For this purpose, an attempt has been made to conceptually integrate the available evidence with respect to the role of human behavior in the causation of road accidents. From this integrative effort it would seem that the accident rate is ultimately dependent on one factor only, the target level of risk in the population concerned which acts as the reference variable in a homeostatic process relating accident rate to human motivation. Various policy tactics for the purpose of modifying this target level of risk have been pointed out and the theory of risk homeostasis has been speculatively extended to the areas of lifestyle-dependent morbidity and mortality.     

Risk Framework for an Organizational System With Major Components

Many large organizations accomplish their various functions through interactions across their major components. Components refers to functional entities within a large complex organization, such as business sectors, academic departments, or regional divisions. The dependency between the various components can cause risk to propagate through their overall system. This article presents a risk assessment framework that integrates risk across a diverse set of components to the overall organization functions. This project addresses three major challenges: aggregating risk, estimating component interdependencies including cycles of dependencies, and propagating risk across components. The framework aggregates risk assessments through a value function for severity that is evaluated at the expected outcome of accomplishing planned goals in terms of performance, schedule, and resources. The value function, which represents risk tolerance, scales between defined points corresponding to failure and success. Different risk assessment may be aggregated together. This article presents a novel approach to establishing relationships between the various components. This article develops and compares three network risk propagation models that characterize the overall organizational risk. The U.S. Air Force has applied this risk framework to evaluate success in hypothetical future wars. The analysts employing this risk framework have informed billions of dollars of strategic investment decisions.     

Risk analysis under attack: How risk science can address the legal,social, and reputational liabilities faced by risk analysts

The role of the risk analyst is critical in understanding and managing uncertainty. However, there is another type of uncertainty that is rarely discussed: The legal, social, and reputational liabilities of the risk analyst. Recent events have shown that professionals participating in risk analysis can be held personally liable. It is timely and important to ask: How can risk science guide risk analysis with consideration of those liabilities, particularly in response to emerging and unprecedented risk. This paper studies this topic by: (1) Categorizing how professionals with risk analysis responsibilities have historically been held liable, and (2) developing a framework to address uncertainty related to those potential liabilities. The result of this framework will enable individual analysts and organizations to investigate and manage the expectations of risk analysts and others as they apply risk principles and methods. This paper will be of interest to risk researchers, risk professionals, and industry professionals who seek maturity within their risk programs.     

Risk Comparisons, Conflict, and Risk Acceptability Claims

Despite many claims for and against the use of risk comparisons in risk communication, few empirical studies have explored their effect. Even fewer have examined the public's relative preferences among different kinds of risk comparisons. Two studies, published in this journal in 1990 and 2003, used seven measures of "acceptability" to examine public reaction to 14 examples of risk comparisons, as used by a hypothetical factory manager to explain risks of his ethylene oxide plant. This study examined the effect on preferences of scenarios involving low or high conflict between the factory manager and residents of the hypothetical town (as had the 2003 study), and inclusion of a claim that the comparison demonstrated the risks' acceptability. It also tested the Finucane et al. (2000) affect hypothesis that information emphasizing low risks-as in these risk comparisons-would raise benefits estimates without changing risk estimates. Using similar but revised scenarios, risk comparison examples (10 instead of 14), and evaluation measures, an opportunity sample of 303 New Jersey residents rated the comparisons, and the risks and benefits of the factory. On average, all comparisons received positive ratings on all evaluation measures in all conditions. Direct and indirect measures showed that the conflict manipulation worked; overall, No-Conflict and Conflict scenarios evoked scores that were not significantly different. The attachment to each risk comparison of a risk acceptability claim ("So our factory's risks should be acceptable to you.") did not worsen ratings relative to conditions lacking this claim. Readers who did or did not see this claim were equally likely to infer an attempt to persuade them to accept the risk from the comparison. As in the 2003 article, there was great individual variability in inferred rankings of the risk comparisons. However, exposure to the risk comparisons did not reduce risk estimates significantly (while raising benefit estimates), and Conflict-Claim respondents found the risk of the hypothetical factory less acceptable than No-Conflict respondents. Results suggest that neither risk comparisons nor risk acceptability claims are automatically anathema to audiences, but they may have tiny or unintended effects on audience judgments about risky situations.     

Risk Characterization for Nanotechnology

Nanotechnology is a broad term that encompasses materials, structures, or processes that utilize engineered nanomaterials, which can be defined as materials intentionally designed to have one or more dimensions between 1 and 100 nm. Historically, risk characterization has been viewed as the final phase of a risk assessment process that integrates hazard identification, dose‐response assessment, and exposure assessment. The novelty and diversity of materials, structures, and tools that are covered by above‐defined “nanotechnology” raise substantial methodological issues and pose significant challenges for each of these phases of risk assessment. These issues and challenges culminate in the risk characterization phase of the risk assessment process, and this article discusses several of these key issues and approaches to developing risk characterization results and their implications for risk management decision making that are specific to nanotechnology.     

风险相关性下的信用风险、市场风险和操作风险集成度量

商业银行各种风险之间相关性的存在,对其整体风险的度量产生重要影响。本文针对商业银行的信用风险、市场风险和操作风险这三类主要风险,在考虑相关性基础上给出了风险集成过程,通过copula函数和蒙特卡洛模拟方法计算了商业银行的整体风险,同时研究了风险分散化效应和在不同copula函数下整体风险的变化情况。最后以主流文献中的数据做了实证分析,结果显示本文提出方法能够很好的描述风险损失之间的相关性,同时在能够抵御相同风险的情况下考虑相关性下的在险值与简单相加得到的在险值相比要小,这能为银行业提高资金利用率提供了一定的理论和方法依据。