Dear reader,
Currently, I have a panel dataset with the variables Firm_ID and Year. Across years firms drop out of the sample, but new ones also join. How could I calculate the number of firms that drop from say, 1990 to 1991?
Initially when I thought I had no "joiners" I had just calculated the number of distinct IDs per year, but that's how I realized I had joiners.
Kind regards,
Luis