granger test

[seg_b]

Hi,

I'm trying to do a non causality test of Granger on Eviews. I just want to know how to chosse the optimal lag number.
Of course, I know I need to use an optimal number of lags to do my test, beacause of the changes of my results when I use some differents lags.
My data are daily.

Thanks a lot for helping.