Dear all,

I will please like to find out if i combine two cross sectional data to form a panel will my number of observations double
e.g cross sectional data 1=4000 and cross sectional data 2=4000 will panel be n=8000 or n=4000 if individuals are same in both data.

or if

cross sectional data 1=4000 and cross sectional data 2=3500 will my data be n=7500 or 4000 for same individuals

and if i have an unbalanced panel how do i make it balanced. I will really appreciate a reply.