Dear Stata users,
I am searching a function in stata to program peer groups.
In my benchmarking study about American industries I want to compare companies by its sales, earnings etc.
I use the three digit industry code to classify the industries (sic-codes). The peer group must be within the same industry.
Here, the purpose is to compute the mean or median of the sales and to see if the respective firm's performance is below or above the mean or the median.
But, the peer group of firm X contains all the companies with the same digit code but *not* firm X (otherwise I would compare X with itself)
To conclude:
year sic-code firm sales mean median
1990 333 X 10 ? ?
1990 333 Y 20 ? ?
1990 333 Z 30 ? ?
---------------------------------------------
1990 334 A 21 ? ?
1990 334 B 5 ? ?
---------------------------------------------
1991 etc. ...
so, in 1990
the peer group mean/median for X must contain (20+30) but not 10
the peer group mean/median for Y must contain (10+30) but not 20
the peer group mean/median for Z must contain (10+20) but not 30
and so on...
is there a way to program is stata something like
by year sic-code, sort: egen median/mean *without the sales of the firm X / firm Y etc.*
Please note, it is basically more important for me to obtain the *median* than the mean peer group due to the outlier problem of the mean function.
So, please help me find a solution to the median peer group first.
Many thanks in advance!
Bastian
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