Dear all,

I need some help. Well, I have a database in the structure of a balanced panel. I have to select a subset since my database is very large. However, I need to keep the panel structure balanced, that is, select the panel identifier in order to keep its information from the first to the last year of the base, keeping the panel balanced. In addition, I want to maintain the representativeness of the variables in the subset generated. Can anyone help me with these issues?

Thanks in advace!