在经济下行和违约规模逐步增加的环境下,投资者对市场的尾部风险比较敏感。借鉴Fama and MacBeth(1973)的因子分析方法,我们在截面维度和时间序列维度验证了债券收益与尾部风险的关系,发现尾部风险每增加一个标准差,债券年化超额收益约增加4.15%。通过做多高尾部风险组债券和做空低尾部风险组债券得到的投资组合平均有月度0.58%的超额收益。实证结果验证了市场对尾部风险的定价机制——投资者面对资产分布的不确定时对损失更为厌恶和用尾部风险历史数据分析违约风险的概率。
The rapidly growing credit derivatives market requires to value credit derivatives and portfolios of credit risks,and how to measure the correlation between each credit risk is the key problem of valuation.In this paper,we introduce a new technology——Copula function——to integrate single credit risk,and discuss how to use copula function to manager portfolios of credit risks and value credit derivatives. Credit risks are the main problems for Chinese banks.Credit derivatives have a function to transfer credit risks,Credit derivatives market grows very quickly,they are sure to become a very important part of financial market.Study the valuation techniques for credit derivatives,design appwpriate derivatives for Chinese financial institutions,and seek useful methods to mangage credit risks are helpful to improve the benefits and asset quality of Chinese commercial banks.
