Special thanks to P. Seed!!! Thank you so much!!!
I'm sorry that I didin't make my problem clearer. Supposes the 10 firms (obs
1-10)have the same ind4 as 1041, I will consider them to belong to industry
1041. But as to firm 11, there is only one firm in its 4-digit ind code
1044, I will consider it belong to industry 104, which will contain all the
11 firms with the same ind3, 104. In other words, firm 1-10 belong to
industry 1041 and industry 104 simultaneously.
obs Tobin's q ind4 ind3 ind2 ind1 industry size grp-under-ind4
grp-under-ind4 mean-of-grp
1 1041 104 10 1 1041 1 small ?
2 1041 104 10 1 1041 3 small ?
3 1041 104 10 1 1041 2 small ?
4 1041 104 10 1 1041 5 middle ?
5 1041 104 10 1 1041 4 middle ?
6 1041 104 10 1 1041 9 large ?
7 1041 104 10 1 1041 8 middle ?
8 1041 104 10 1 1041 11 large ?
9 1041 104 10 1 1041 10 large ?
10 1041 104 10 1 1041 7 middle ?
11 1044 104 10 1 104 6 N.A. ?
Subsequently I will subdivide firms in each industry into small, middel and
large groups according to firm size. The small group contains the smallest
30% firms in size within an industry, the middle group contains the middle
40% firms in size (30% to 70%), and the large group contain firms whose size
belongs to the largest 30% in that industry. How I can subdivide firms
according to size in an industry and assign a firm to a group according to
its size? I also need to get the median or mean value of Tobin's q for each
of these groups within an industry.
For industry 1041, there are 10 firms, firm 1 through 10, and For indutry
104, there are 11 firms. Take firm 1 as an example, according to its size,
it belongs to samll group under ind4 as 1041. Firm 1's industry-size
adjusted Tobin's q = firm 1's Tobin'q - the mean Tobin's q of small group
under ind4. As to firm 11, first I need to assign firm 11 into a group under
ind3 of 104 according to its size (industry 104 contain all the 11 firms, a
firm can belong to different groups under different industry codes), then I
have to get the mean value of Tobin's q of firms in the same group as firm
11.
I hope that you will understand my problems now and help me out, I really
apprecaite your great helps!!!
Bing
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