Before revision:  This model is able to capture the so-called "  panic effect", which occurs whenever systematic risk becomes the dominant factor. consequently , in contrast to other models , this new model is as reactive as the implied volatility indices .
After revision:  This model is able to capture the so-called " panic effect", which occurs whenever systematic risk becomes the dominant factor. consequently , in contrast to other models , this new model is as reactive as the implied volatility : the model adjusts itself in an instantaneous way to each variation of the single stock price or the stock index price and the adjustment is highly correlated to implied volatility changes .