Hello Sir,

I have 4 separate -excel files required to merge in one excel file. This is the longitudinal data sets but it has a different range of individuals. The individuals and duration vary each other. For example, One excel sheet has 38 individuals and 30 years but others have 50 individuals and 35 years. I need to sort common individuals and the number of years, that make the balanced data.

Noted that my professor told me to use the following code to sort the data.
NACE REV. 2 - ISIC REV. 4
Source Target
gen nace==. A A
replace nace= 1 if isic== 1

I don't have any idea how I can do it. Pls, thanks for your kind cooperation.