Hi.
I am doing two time-series regressions, both regressions contain 3 mutual variables with several other variables in them.
Set 1: A B C D E F G
Set 2: A B C H I J K L M
I am running covariance matrix (looking at the correlation amongst variables for both regressions). However, since the 3 mutual variables are present for both regressions, do I still include these 3 variables in the covariance matrices for both regression? I am not sure because the correlation coefficients for the same mutual variables are different.
For instance,
Set 1: A-B = 0.5678
Set 2: A-B = -0.4892
Any helps will be greatly appreciated.
Thank you!