GM, you're right-- by kappa_g, I mean speed of mean reversion for expected earnings growth. And by original paper, I mean the paper at
http://papers.ssrn.com/sol3/papers.cfm? ... 20Download (Bakshi Chen 2001)I also agree that the model is somewhat difficult to test emprically.. that's why I'm looking to others for help. I have tried to use a combination of randomized algrorithms and least-squares optimization, but the parameter estimates do not seem very robust. So as a sanity check, I thought I would check the comparative statics discussed in (Bakshi Chen 2001) on page 10. There, they basically calculate the integral from formula (17) for the P/E ratio for a fixed parameter set, and vary one of the parameters such as kappa_g. Their results are also depicted at the end of the paper in Figure 3. But when I use Matlab to try to reconstruct the plots, I see something quite different for the speed of mean reversion plots-- namely, they have the opposite effect. Stronger mean reversion in R => a lower P/E ratio. I'm wondering if someone else did this simple test, if they would see the same thing.Thanks for the interest.