st: Creating a dummy for each large firm in each fiscal year (foreach command)

[Martijn S <martstouthart@gmail.com>]

Hello,

This is my problem. I have a sample which uniquely identifies firms by
the variable gvkey. Now I want to run a regression over firms that are
defined as large and therefore I want to create a dummy.  I define
firms as large on basis of their 2008 total assets. As a result I
created a dummy variable called largefirmdummywith the command:
generate largefirmdummy=1 if fyear==2008 & at > 100. Next I entered
the following command: generate gvkeylarge = gvkey if
largefirmdummy==1. So I now have the variable gvkeylarge which
contains the gvkey of each large firm.

Suppose now, gvkeylarge contains a firm with the 'gvkey' 1166. I have
this firm in my sample from 1999-2010, as is can be seen from variable
gvkey which contains 12 times the gvkey 1166.

So from 1999-2010 I want to create a dummy which has a value of 1 in
for this firm. This can be done by
the following command:

replace largefirmdummy=1 if gvkey==1166
replace largefirmdummy=1 if gvkey==8071
replace largefirmdummy=1 if gvkey==8546

etc....

Thus I want to create a loop which looks at every unique number if
gvkeylarge, than looks at looks at the variable gvkey
if it containts this unique number, and when this is the case the loop
must add a 1 to the variable largefirmdummy.


I tried the foreach command but I cannot get this working. I hope that
someone can help me out.


Thanks,

Martijn







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