Measuring financial risks with copulas

This paper is concerned with the statistical modeling of the dependence structure of multivariate financial data using the concept of copulas. We select some special copulas and identify the type of dependency captured by each one. We fit copulas to daily returns and simulate from the fitted models. We compare the effect of the choice of copula on risk measures and assess the variability of one-step-ahead predictions of portfolio losses. We analyze extreme scenarios and fit extreme value copulas to the block maxima and minima from daily returns. The stress scenarios constructed are compared to those obtained using models from the extreme value theory. We illustrate the usefulness of the copula approach using two stock market indexes.     

Convex risk measures for the aggregation of multiple information sources and applications in insurance

We propose a novel class of convex risk measures, based on the concept of the Fréchet mean, designed in order to handle uncertainty which arises from multiple information sources regarding the risk factors of interest. The proposed risk measures robustly characterize the exposure of the firm, by filtering out appropriately the partial information available in individual sources into an aggregate model for the risk factors of interest. Importantly, the proposed risks can be expressed in closed analytic forms allowing for interesting qualitative interpretations as well as comparative statics and thus facilitate their use in the everyday risk management process of the insurance firms. The potential use of the proposed risk measures in insurance is illustrated by two concrete applications, capital risk allocation and premia calculation under uncertainty.     

Bounds for option prices and expected payoffs

This article sharpens Lo's upper bounds for option prices using an alternative approach with the assumption that the underlying asset price is continuously distributed. The increased sharpness is obtained using additional information about the distribution of the underlying assets. It is shown in this article that a large portion of Lo's upper bounds is the maximum of our bounds over all possible distributions.     

Bounds of ruin probabilities

Abstract

Upper and lower bounds are obtained for ruin probabilities with safety margin ρ in the case of known expectation, variance and range for the claim severity function.     

系统性金融风险的识别与防范

系统性风险与集中度风险、金融危机既有区别,又有联系。银行金融机构的集中度风险是引发系统性风险的主要因素,系统性风险又是导致金融危机的直接原因。为避免和防范系统性风险,监管部门要把防范系统性风险的重点放在对银行金融机构集中度风险的监控上,加强对银行金融机构集中度风险的外部监管,不断向银行金融机构提示集中度风险,督促银行金融机构建立严格的集中度风险防控机制。银行金融机构也要有稳健的发展战略和谨慎的风险偏好,合理布局经营,严格把控资产分布结构,避免集中度风险,以便从根本上防范系统性风险,避免出现危害更大的金融危机。     

Criteria for the Stochastic Ordering of Random Sums,with Actuarial Applications

It is shown that vectors ( S M 1 , … , S Mn ) and ( S' M'1 , …, S' M'n ) of random sums of positive random variables are stochastically ordered by upper orthant dependence, lower orthant dependence, concordance or by the supermodular ordering whenever their corresponding random numbers of terms ( M 1 , … , M n ) and ( M' 1 , … , M' n ) are themselves ordered in this fashion. Actuarial applications of these results are given to different dependence structures for the collective risk model with several classes of business.     

Risks for the long run: Estimation with time aggregation

The discrepancy between the decision and data-sampling intervals, known as time aggregation, confounds the identification of long-, short-run growth, and volatility risks in asset prices. This paper develops a method to simultaneously estimate the model parameters and the decision interval of the agent by exploiting identifying restrictions of the Long Run Risk (LRR) model that account for time aggregation. The LRR model finds considerable empirical support in the data; the estimated decision interval of the agents is 33 days. Our estimation results establish that long-run growth and volatility risks are important for asset prices.     

Law of large numbers and large deviations for dependent risks

We analyse the mathematical structure of models for large risk portfolios, especially for credit risk models. These risk portfolios are modelled using a multivariate mixture model for the dependence structure between the risks. The dependence structures are characterized by latent variables Θ, which play the role of systematic risks. We show that, depending on the choice of the distribution of Θ, there are different asymptotic behaviours for the aggregated risk portfolio, namely law of large numbers/central limit theorem behaviour and large deviation behaviour.     

Good-Deal Option Price Bounds for a Non-Traded Event with Stochastic Return: A Note

Cochrane and Sa'a-Requejo (2000, Journal of Political Economy) proposed the good-deal price bounds for the European call option on an event that is not a traded asset, but is correlated with a traded asset that can be used as an approximate hedge. One remarkable feature of their model is that the return on an event process explicitly appears in the option price bounds formula, which offered a contrast with the standard option pricing model. We show that the good-deal option price bounds on a non-traded event are obtained as a closed-form formula, when the return on an event is governed by a mean reverting process.     

船舶抵押融资的法律风险研究

船舶抵押融资贷款项目中,银行应注重船舶的船龄、结构及船况,并充分考虑在航运市场大幅下滑时船舶价值大幅降低的可能性、船舶的保险是否充分、船舶管理人或船东管理船舶的水平、船舶管理人在市场中的信用和船舶是否入级及其船级社的声誉。在船舶抵押放贷之后,银行要督促抵押人及时偿还每一期贷款,并建立对抵押船舶的监控及跟踪体系。     

商业银行风险拨备制度研究

本文首先从商业银行风险管理和会计理论角度研究分析了建立风险拨备制度的理论基础。其次回顾总结了我国商业银行风险拨备制度的历史沿革和发展现状，并结合国内五家上市银行2004年年报,简要分析了目前国内商业银行风险拨备管理情况和制度建设现状。在此基础上，笔者提出构建商业银行全面风险拨备体系的构想，结合上市银行计提减值准备的实际情况，对贷款、投资和应收款项减值准备计提相关问题进行具体分析，并提出在实施全面风险拨备管理过程中应该注意转变观念、规范操作、加强审计和监管力度、加大配套环境和制度建设等问题。     

商业银行风险拨备制度研究

本文首先从商业银行风险管理和会计理论角度研究分析了建立风险拨备制度的理论基础。其次回顾总结了我国商业银行风险拨备制度的历史沿革和发展现状,并结合国内五家上市银行2004年年报,简要分析了目前国内商业银行风险拨备管理情况和制度建设现状。在此基础上,笔者提出构建商业银行全面风险拨备体系的构想,结合上市银行计提减值准备的实际情况,对贷款、投资和应收款项减值准备计提相关问题进行具体分析,并提出在实施全面风险拨备管理过程中应该注意转变观念、规范操作、加强审计和监管力度、加大配套环境和制度建设等问题。     

运用信号分析法建立我国的金融风险预警系统

在全球金融自由化程度不断加深的大背景下,我国金融对外开放程度不断加深,建立适合国情的金融风险预警系统的重要性和紧迫性日益明显.借鉴国际上影响广泛的KLR信号分析法,本文根据国情建立了一套金融风险预警系统,选取一系列系统性及非系统性风险监测指标,确定不同风险状态下的预警界限,通过数据处理,最终进行风险的灯号显示.在此基础上,结合我国的具体数据进行了实证分析,发现我国金融风险在系统性风险方面表现为财政风险突出,非系统性风险则聚集在银行系统.因此,我国有必要从财政、银行资本及内控制度、资本市场和金融监管多方面入手,构建金融风险的防范机制.     

含外资股公司股权分置改革诉讼风险分析

含B股、H股、N股公司的股权分置改革涉及比较复杂的法律关系,有可能引发外资股股东提出的国际集团诉讼.本文试对含B股、H股、N股公司的股权分置改革的民事与行政诉讼风险进行了剖析,并提出了积极稳妥推进A B股、H股、N股公司股权分置改革的相关建议.     

Accounting for the Accuracy of Beta Estimates in CAPM Tests on Assets with Time-varying Risks

This paper advocates two ways to make more efficient use of available information in reducing the bias of the risk premium estimate in two-pass tests of the CAPM. First, explicit modelling of the time-variability of betas can improve the accuracy of the beta forecasts. Second, the cross-sectional information available can be exploited more efficiently using individual stocks instead of portfolios provided that noisy beta predictions are given a smaller weight than more accurate ones. This paper proposes an adjustment of the cross-sectional regressions of excess returns against betas to give larger weights to more reliable beta forecasts. A significant positive relationship between returns and the beta forecast is obtained when the proposed approach is applied to data from the Helsinki Stock Exchange, while the traditional Fama–MacBeth approach as such finds no relationship at all.     

Weekly Pattern of Exchange Rate Risks: Evidence from Ten Asian-Pacific Currencies

This paper examines the day-of-the-week effect on the currency returns of ten Asian-Pacific countries and differs from previous studies in that it tests directly the effect on higher moments of currency returns. Using ten-year daily data, the results first show that currency returns are non-normally distributed, particularly with very large kurtosis. The hypothesis of equal higher moments (e.g., skewness or kurtosis or both) cannot be rejected by any pair of weekdays only for the Australian dollar. For the remaining nine currencies, the same hypothesis is rejected by at least one pair of weekdays. Six currencies reject the hypothesis in all pairs of weekdays, supporting the existence of the day-of-the-week effect on higher moments. Further analysis shows that Rogalski's effect exists on the higher moments of three currencies because the day-of-the-week effect exists only in non-January months. Sub-period analysis indicates that the weekly patterns on higher moments are quite consistent across two sub-periods for all currencies except the Taiwanese dollar. This revised version was published online in August 2006 with corrections to the Cover Date.     

典当业潜在洗钱风险分析和对策建议

在非银行业金融机构反洗钱监管要求日趋严格的情况下,如何防范典当业的洗钱风险,成为摆在反洗钱监管部门及典当业管理部门面前亟待解决的问题。本文立足于中国典当业的现状,分业务环节对典当业潜在的洗钱风险进行了逐一分析．并在FATF“反洗钱40条建议”的框架下,对如何防范典当业的洗钱风险给出了对策建议。     

网上银行的法律风险管理探讨

随着金融创新和网上银行业务的迅猛发展,网上银行法律风险管理问题日显重要。本文认为中国要借鉴国内外银行在网上银行法律风险管理架构与工作机制等方面的做法与经验,结合中国网上银行法律风险管理现状,着力解决好相关法律条文仍需细化、管理制度执行落实亟待加强、管理配套机制仍显不足、管理运行尚不到位等问题。本文从转变管理思维、创新管理模式、搭建管理平台、打造管理人才队伍、优化管理环境等5个方面,提出了强化网上银行法律风险管理的对策措施,以期为进一步优化网上银行法律风险管理体系并提升风险管理水平提供思路。     

Option Pricing Bounds and the Elasticity of the Pricing Kernel

In this paper we use power functions as pricing kernels to derive option-pricing bounds. We derive option pricing bounds given the bounds of the elasticity of the true pricing kernel. The bounds of the elasticity of the true pricing kernel are closely related to the bounds of the representative investor's coefficient of relative risk aversion. This methodology produces a tighter upper call option bound than traditional approaches. As a special case we show how to use the Black–Scholes formula to obtain option pricing bounds under the assumption of lognormality.