系统工程理论与实践
繫統工程理論與實踐
계통공정이론여실천
Systems Engineering—Theory & Practice
2013年
10期
2471~2478
,共null页
Copula函数 多因子模型 因子系数估计 秩相关系数 在险价值 条件在险价值
Copula函數 多因子模型 因子繫數估計 秩相關繫數 在險價值 條件在險價值
Copula함수 다인자모형 인자계수고계 질상관계수 재험개치 조건재험개치
Copula function; multi-factor model; factor coefficient estimation; rank correlation coefficient;value-at-risk; conditional value-at-risk
主要研究用多因子模型刻画金融资产收益率时,因子载荷系数的合理估计问题.以因子系数的金融意义为出发点,并结合Copula的相关理论,提出了一种新的因子系数估计方法.新方法用Copula函数描述各个因子与金融资产收益所服从的联合分布;从因子系数的正负及其发生的概率,金融资产收益率随因子波动的大小两方面来估计因子系数的值.在此基础上,对因子系数新的估计公式做了进一步调整,强调了尾部相关性对因子系数取值的影响.基于中国证券市场的交易数据,对不同估计方法进行了实证研究.通过分别计算统计量R-square的值,随机误差项的均方偏差,尾部均方偏差以及投资组合的在险价值与条件在险价值等方法,实际论证了文中所提新的因子系数估计的改进方法优于因子系数估计的新的Copula方法,而后者又明显好于传统的线性回归方法.
主要研究用多因子模型刻畫金融資產收益率時,因子載荷繫數的閤理估計問題.以因子繫數的金融意義為齣髮點,併結閤Copula的相關理論,提齣瞭一種新的因子繫數估計方法.新方法用Copula函數描述各箇因子與金融資產收益所服從的聯閤分佈;從因子繫數的正負及其髮生的概率,金融資產收益率隨因子波動的大小兩方麵來估計因子繫數的值.在此基礎上,對因子繫數新的估計公式做瞭進一步調整,彊調瞭尾部相關性對因子繫數取值的影響.基于中國證券市場的交易數據,對不同估計方法進行瞭實證研究.通過分彆計算統計量R-square的值,隨機誤差項的均方偏差,尾部均方偏差以及投資組閤的在險價值與條件在險價值等方法,實際論證瞭文中所提新的因子繫數估計的改進方法優于因子繫數估計的新的Copula方法,而後者又明顯好于傳統的線性迴歸方法.
주요연구용다인자모형각화금융자산수익솔시,인자재하계수적합리고계문제.이인자계수적금융의의위출발점,병결합Copula적상관이론,제출료일충신적인자계수고계방법.신방법용Copula함수묘술각개인자여금융자산수익소복종적연합분포;종인자계수적정부급기발생적개솔,금융자산수익솔수인자파동적대소량방면래고계인자계수적치.재차기출상,대인자계수신적고계공식주료진일보조정,강조료미부상관성대인자계수취치적영향.기우중국증권시장적교역수거,대불동고계방법진행료실증연구.통과분별계산통계량R-square적치,수궤오차항적균방편차,미부균방편차이급투자조합적재험개치여조건재험개치등방법,실제론증료문중소제신적인자계수고계적개진방법우우인자계수고계적신적Copula방법,이후자우명현호우전통적선성회귀방법.
This paper studied the reasonable estimation of factor coefficients when the multi-factor model is used to describe the return rates of financial assets. New methods to estimate factor coefficients were proposed by examining financial implication of factor coefficients and utilizing the Copula theory. Through modeling the joint distribution of each factor and the return rate of the financial asset with the Archimedean Copula function, the new method estimated factor coefficients in two steps: the sign of the coefficient and its occurring probability were first determined by the Kendall's tau; the fluctuation scale of the factor coefficient was then calculated as the ratio of the variation of the financial asset's return rate with respect to the change of each factor. Moreover, the above method was further improved by emphasizing the influence of distribution tails on the factor coefficient, which was done by introducing the tail correlation. Empirical tests were carried out with trading data from Chinese stock markets. The practicality and advantage of our new methods were demonstrated by calculating the R-square value, the mean-square deviation of the random error term, and the corresponding tail mean-square deviation of the determined multi-factor models with different factor coefficient estimation methods, as well as their application to the value-at-risk and conditional value-at-risk calculations of the portfolio. Empirical results show that the improved new method is the best, while the new method is obviously better than the traditional linear regression method.