Portfolio Optimization under Lower Partial Risk Measures

Portfolio management using lower partial risk (downside risk) measures is attracting more attention of practitioners in recent years. The purpose of this paper is to review important characteristics of these riskmeasures and conduct simulation using four alternative measures, lower semi-variance, lower semi-absolute deviation, first order below targetrisk and conditional value-at-risk.We will show that these risk measures are useful to control downside risk whenthe distribution of assets is non-symmetric. Further, we will propose a computational scheme to resolve the difficultyassociated with solving a large dense linear programming problems resulting from these models. We will demonstrate that this method can in fact solve problems consisting of10⁴ assets and 10⁵ scenarios within a practical amount of CPU time.     

Credit Risk in Two Institutional Regimes: Spanish Commercial and Savings Banks

Although credit risk is an important factor that financial institutions must cope with, the determinants of bank problem loans have been little studied. Using panel data, we compare the determinants of problem loans of Spanish commercial and savings banks in the period 1985–1997, taking into account both macroeconomic and individual bank level variables. The GDP growth rate, firms, and family indebtedness, rapid past credit or branch expansion, inefficiency, portfolio composition, size, net interest margin, capital ratio, and market power are variables that explain credit risk. However, there are significant differences between commercial and savings banks, which confirm the relevance of the institutional form in the management of credit risk. Our findings raise important bank supervisory policy issues: the use of bank level variables as early warning indicators, the advantages of bank mergers from different regions, and the role of banking competition and ownership in determining credit risk.     

商业银行控制利率风险的技术和工具

随着我国利率市场化改革进程的加快以及我国与世界经济和金融联系的加强 ,利率波动的频率和幅度将越来越大 ,因而商业银行将面临更大的利率风险。为此 ,本文介绍了西方商业银行如何运用持续期缺口、远期利率协议、期货、期权等技术和工具来管理和控制利率风险 ,以期对我国的商业银行有所借鉴。     

关于房地产投资风险类型的研究

本借鉴了证券投资组合理论和资本资产定价模型的思想，将房地产投资风险划分为系统风险和非系统风险，并结合我国的实际情况，对房地产投资风险的类型进行了深入的研究。     

论我国地方财政风险的个性特征

我国地方财政风险，不同于一般的财政风险。从整体考察，它具有分散性、非均衡性和传导性；从结构考察，具有隐蔽性、发展性和内生性，同时它又受外部因素的影响很大。     

经济增长在险水平、条件波动性与经济增长态势研究

经济增长在险水平（GaR）和条件标准差（CSD）能够有效地度量国家经济风险波动的单向性和双向性。利用动态时窗和条件异方差模型，我们发现我国国家经济风险与经济周期波动密切相关，目前的国家风险状态已经体现出明显的稳定性。利用协整关系检验，我们发现我国国家经济风险与经济增长水平之间存在正相关的长期均衡关系，因此采取积极经济政策的“反周期”干预，所诱发的适度经济波动将有且经济快速稳定增长。     

The minimum variance hedge and the bankruptcy risk of the firm

In this paper, we analyze the influence of hedging with forward contracts on the firm's probability of bankruptcy (POB). The minimization of this probability can serve as a substitute for the maximization of shareholders' wealth. It is shown that the popular minimum variance hedge is generally neither necessary nor sufficient for the minimization of the firm's POB. Moreover, our model suggests a correction of the widespread view that a reduction in the variance of the future value of the firm is inevitably accompanied by a reduction in its default risk. We derive an analytical solution for the variance-minimizing hedge ratio of a firm exposed to both input and output price uncertainty that takes into account the issue of correlation. Based on this solution, we provide a graphical analysis to prove our claim that there is a fundamental difference between hedging policies focused on bankruptcy risk and those following conventional wisdom even if positive correlation constitutes a “natural” hedge.     

Locally Greater Vulnerability to Background Risk

Willingness to take on risk is influenced by the presence of fair and unfair background risks for decision makers who are risk vulnerable as defined by Gollier and Pratt [1996], for these decision makers are more risk averse when they possess such an uninsurable background risk. We present an alternative derivation of the index of local vulnerability based on Diamond and Stiglitz [1974] compensated increases in risk, such that risk aversion increases with the introduction of any small fair background risk if and only if the index of local vulnerability is positive. We establish that the increase in risk aversion is greater for those who are more vulnerable as measured by the index of local vulnerability.     

Incorporating Collateral Value Uncertainty in Loss Given Default Estimates and Loan-to-value Ratios

We present a model of risky debt in which collateral value is correlated with the possibility of default. The model is then used to study the expected loss given default, primarily as a function of collateral. The results obtained could prove useful for estimating losses given default in many popular models of credit risk which assume them constant. We also examine the problem of determining sufficient collateral to secure a loan to a desired extent. In addition to bank practitioners, regulators might find our analysis useful in reviewing banks’ lending standards relative to current collateral values. In particular, the current proposals for The New (Basel) Capital Accord involve options for the use of banks’ own loss given default estimates which might benefit from the analysis in this paper.