Dear all,

I have an unbalanced panel dataset, which means that not all entities have data for all years.

I am aware that it is okay to have unbalanced data to run regressions. However, I am curious about the entities that have data for every year (or should I say the repeated entities?); and I want to create a subsample from the unbalanced data which only includes those repeated entities. Am I looking for a strongly balanced data set here?

If yes, is there any way to convert a data set from unbalanced to strongly balanced?

Thank you for your help in advance.