希望能帮到你,因为刚好作业遇到这个题目
假设股权价值Et=f(At,t)=f 对其直接运用伊藤定理
其中dAt=udt+sigma(dWt); dAt的平方=At平方*sigma平方*dt
得出dEt=(...)dt+(...)dWt
在对比dEt=uEdt+sigmaE(dWt)
得出sigmaE等于前面的得出的系数,令t=0,再用方程组第一个等式即可得
详情参考文献即可得
American Finance Association
On the Pricing of Corporate Debt: The Risk Structure of Interest Rates
Author(s): Robert C. Merton
Source:
[size=20.4468px]The Journal of Finance,
Vol. 29, No. 2, Papers and Proceedings of the Thirty-
Second Annual Meeting of the American Finance Association, New York, New York,
December 28-30, 1973 (May, 1974), pp. 449-470
Published by: Wiley for the American Finance Association
Stable URL: http://www.jstor.org/stable/2978814