calibration

calibration   for what?   不明白你说的什么标准？

calibrate to historical price series if you are interested in the real world dynamics, for CEV, the underlying price after transformation is non-central chi-square distributed, and maximum likelihood estimator can be used
calibrate to option prices if you are interested in the risk neutral dynamics, but for CEV, it's impossible to get an implied volatility smile, it's always a skew

很不错滴，呵呵呵

4# irvingy
你的意思是按偏度卡方的分布，用极大似然估计量做那个变量的值，对吗？ 能解释一下原由吗？谢谢