Re: st: Identify a Panel Structure with Incoherent ID and NAME Variable

[Robert Picard <picard@netbox.com>]

You can use -group_id- (available on SSC) to consolidate your ID codes
when Firm names match. Note that this will miss "General Motors
Stillwater" because the name is unique and the ID is also unique.

Hope this helps,

Robert

*----------- begin example -------------
clear
input obs Year str9 ID str36 Firm
 1  1999  000846217  "Stillwater Power"
 2  2000  000846217  "Stillwater Power"
 3  2001  000846217  "Oklahoma Stillwater Power Co."
 4  2002  000846217  "Oklahoma Stillwater Power Co."
 5  2003  000846217  "Oklahoma Stillwater Power Co."
 6  2004  000846217  "Stillwater Power Co."
 7  2005  000846217  "Stillwater Power Co."
 8  2006  000846217  "Stillwater Power Co."
 9  2007  000846217  "Stillwater Power Co."
10  1999  001834488  "Cushing Farming"
11  2000  001834488  "Oklahoma Cushing Farming"
12  2001  001834488  "Oklahoma Cushing Farming"
13  2002  001834488  "Cushing Farming"
14  2003  001834488  "Cushing Farming"
15  2004  001834488  "Oklahoma Cushing Farming"
16  2005  001834488  "Oklahoma Cushing Farming"
17  2006  001834488  "Cushing Farming"
18  1999  001840116  "Perkins Electricity"
19  2000  001840116  "Perkins Electricity"
20  2001  001840116  "Perkins Electricity"
21  2002  001840116  "Perkins Electricity"
22  2003  001840116  "Oklahoma Perkins Electricity"
23  2005  001840116  "Perkins Electricity"
24  1999  177725736  "General Motors Stillwater"
25  2007  702639116  "Cushing Farming"
26  2004  70270423X  "Perkins Electricity"
27  2006  70270423X  "Perkins Electricity"
28  2007  70270423X  "Oklahoma Perkins Electricity"
29  2000  714509511  "(Oklahoma)General Motors Stillwater"
30  2001  714509511  "(Oklahoma)General Motors Stillwater"
31  2002  714509511  "(Oklahoma)General Motors Stillwater"
32  2003  714509511  "(Oklahoma)General Motors Stillwater"
33  2004  714509511  "General Motors Stillwater Oklahoma"
34  2005  714509511  "General Motors Stillwater Oklahoma"
35  2006  714509511  "General Motors Stillwater Oklahoma"
36  2007  714509511  "GM Stillwater"
end

* type -ssc install group_id- to install
clonevar newid = ID
group_id newid, matchby(Firm)

sort newid ID Year obs
list, noobs sepby(newid)
*------------ end example --------------

On Fri, Aug 26, 2011 at 11:19 PM, 田曦 <txsnowsea@hotmail.com> wrote:
>
>
> I have a sample from a very large panel dataset looks like below.  There are 4 unique firms and 9 observations per firm. Firm's name and ID may change  occasionally because it was inputed by different people at different years. Firms name also change occasionally.
> ID is a string variable, may combined with numbers and letters.
>
>  Neither ID or Firm variable can fully identify a true unique firm from all 9 years. For example, "Cushing Farming", "Oklahoma Cushing Farming" are the same company, but with two IDs: 001834488 and 702639116; "Perkins Electricity" and "Oklahoma Perkins Electricity" are the same company, also has IDs: 001834488 and 70270423X;  "General Motors Stillwater",  "(Oklahoma) General Motors Stillwater" and "GM Stillwater" refer the same company, but with only two IDs: 177725736 and  714509511.
>
> obs Year    ID           Firm
>  1  1999  000846217  Stillwater Power
>  2  2000  000846217  Stillwater Power
>  3  2001  000846217  Oklahoma Stillwater Power Co.
>  4  2002  000846217  Oklahoma Stillwater Power Co.
>  5  2003  000846217  Oklahoma Stillwater Power Co.
>  6  2004  000846217  Stillwater Power Co.
>  7  2005  000846217  Stillwater Power Co.
>  8  2006  000846217  Stillwater Power Co.
>  9  2007  000846217  Stillwater Power Co.
> 10  1999  001834488  Cushing Farming
> 11  2000  001834488  Oklahoma Cushing Farming
> 12  2001  001834488  Oklahoma Cushing Farming
> 13  2002  001834488  Cushing Farming
> 14  2003  001834488  Cushing Farming
> 15  2004  001834488  Oklahoma Cushing Farming
> 16  2005  001834488  Oklahoma Cushing Farming
> 17  2006  001834488  Cushing Farming
> 18  1999  001840116  Perkins Electricity
> 19  2000  001840116  Perkins Electricity
> 20  2001  001840116  Perkins Electricity
> 21  2002  001840116  Perkins Electricity
> 22  2003  001840116  Oklahoma Perkins Electricity
> 23  2005  001840116  Perkins Electricity
> 24  1999  177725736  General Motors Stillwater
> 25  2007  702639116  Cushing Farming
> 26  2004  70270423X  Perkins Electricity
> 27  2006  70270423X  Perkins Electricity
> 28  2007  70270423X  Oklahoma Perkins Electricity
> 29  2000  714509511  (Oklahoma)General Motors Stillwater
> 30  2001  714509511  (Oklahoma)General Motors Stillwater
> 31  2002  714509511  (Oklahoma)General Motors Stillwater
> 32  2003  714509511  (Oklahoma)General Motors Stillwater
> 33  2004  714509511  General Motors Stillwater Oklahoma
> 34  2005  714509511  General Motors Stillwater Oklahoma
> 35  2006  714509511  General Motors Stillwater Oklahoma
> 36  2007  714509511  GM Stillwater
>
> I can tell they are the same firms because when I create group identifier for ID and group identifier for Firm variable, they always overlap each other at some point.  I'm thinking how to utilize the overlapping point as an joint knob.
>
> Many Thanks.
>
> Xi Tian
> Department of Economics
> Oklahoma State University
>
>
> *
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>

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