Guys, please help me with a data management question. I spent a day and
cannot figure out.
I have panel dataset, which has firm ID, year, and person ID for the people
working in the firm. I want to calculate the number of staff changes for the
same company for each year. For example, the data is as follows.
FIRM YEAR PERSONID
1 1993 2
1 1993 4
1 1993 276
1 1993 23456
1 1993 853
1 1994 2
1 1994 276
1 1994 853
1 1994 3452
1 1994 224
I already sort firm and year. As you can see, the change of staff for firm 1
in 1994 should be 2 because only person 2, 276 and 853 are retained. I only
want to count how many persons are missing from previous year. I appreciate
your kind help.
Wanli
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