Modeling dependencies between rating categories and their effects on prediction in a credit risk portfolio

The internal‐rating‐based Basel II approach increases the need for the development of more realistic default probability models. In this paper, we follow the approach taken in McNeil A and Wendin J 7 (J. Empirical Finance 2007) by constructing generalized linear mixed models for estimating default probabilities from annual data on companies with different credit ratings. The models considered, in contrast to McNeil A and Wendin J 7 (J. Empirical Finance 2007), allow parsimonious parametric models to capture simultaneously dependencies of the default probabilities on time and credit ratings. Macro‐economic variables can also be included. Estimation of all model parameters are facilitated with a Bayesian approach using Markov chain Monte Carlo methods. Special emphasis is given to the investigation of predictive capabilities of the models considered. In particular, predictable model specifications are used. The empirical study using default data from Standard and Poor's gives evidence that the correlation between credit ratings further apart decreases and is higher than the one induced by the autoregressive time dynamics. Copyright © 2008 John Wiley & Sons, Ltd.     

风险中性分析及其在衍生证券定价中的应用

本文对散见于各文献中的风险中性假设和风险中性概率进行了系统化的分析,归纳出用风险中性假设和风险中性概率对衍生证券进行定价的三个一般步骤,并举例对此进行了应用,这些分析对研究衍生证券定价的研究者具有一定的参考价值。     

New Constructions for IPP Codes

Identifiable parent property (IPP) codes are introduced to provide protection against illegal producing of copyrighted digital material. In this paper we consider explicit construction methods for IPP codes by means of recursion techniques. The first method directly constructs IPP codes, whereas the second constructs perfect hash families that are then used to derive IPP codes. In fact, the first construction provides an infinite class of IPP codes having the best known asymptotic behavior. We also prove that this class has a traitor tracing algorithm with a runtime of O(M) in general, where M is the number of codewords.     

股票市场羊群行为的中美比较

结合最新的资产定价模型和股票市场羊群行为检验思路,提出了股票市场理性与非理性羊群行为检验方法,并将股票市场羊群行为实证研究扩展到不同市场之间的比较.实证研究表明,纽约股票市场的理性羊群行为程度高于中国股票市场,但其非理性羊群行为程度缺低于中国股票市场,中美股票市场交易制度及投资者理念的不同能够解释羊群行为差异.     

高等学校会计核算若干问题的思考

针对《高等学校会计制度》中会计核算方面存在的问题，提出了相应的改进意见。     

Holdings of financial assets: A Markov chain analysis

This paper introduces the Markov chain model as a simple tool for analyzing the pattern of financial asset holdings over time. The model is based on transition probabilities which give the probability of switching $1 of wealth from one asset to another. An illustrative application is provided.     

为其他单位提供债务担保的会计处理

根据对或有事项进行会计处理的谨慎原则,提出对于基本确定的债务人可以清偿债务的或有负债,作为资产单独确定,否则作为或有资产不予确定,但都必须在会计报表附注中披露;增设“预计资产”科目,核算资产负债表日抵押、质押的资产因债务人可能不能偿还债务而将被债权人折价、拍卖、变卖等方式优先受偿的资产,该科目内容在资产负债表单列项目反映,以区别其他资产项目.得出了对各种担保方式形成的或有负债如何进行会计处理.     

Projection Pricing

A significant problem in modern finance theory is how to price assets whose payoffs are outside the span of marketed assets. In practice, prices of assets are often assigned by using the capital asset pricing model (CAPM). If the market portfolio is efficient, the price obtained this way is equal to the price of an asset whose payoff, viewed as a vector in a Hilbert space of random variables, is projected orthogonally onto the space of marketed assets. This paper looks at the pricing problem from this projection viewpoint. It is shown that the results of the CAPM formula are duplicated by a formula based on the minimum-norm portfolio, and this pricing formula is valid even in cases when there is no efficient portfolio of risky assets. The relation of the pricing to other aspects of projection are also developed. In particular, a new pricing formula, called the correlation pricing formula, is developed that yields the same price as the CAPM, but is likely to be more accurate and more convenient than the CAPM in some cases.     

无风险资产有限借入的不相关证券组合有效集的解析表示

本文研究了不允许卖空条件下存在无风险资产有借入的不相关证券有效组合问题,给出了有效集及投资比例的解析表示。     

TIF图像文件与BMP图像文件的转换研究

本文介绍了可识别的TIF图像文件和BMP图像文件的数据格式,提出了用高级语言直接将可识别的TIF图像文件转换成BMP图像文件的程序框图及实施方法.