Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: calculate concentration ratio of four firms


From   Charles Koss <[email protected]>
To   [email protected]
Subject   Re: st: calculate concentration ratio of four firms
Date   Mon, 28 Dec 2009 12:25:09 -0600

I use sas for data management, it is easier! In stata search for the
egen function

-- 
Charles Koss
http://charlesonnet.blogspot.com/


2009/12/27 Alper [iso-8859-9] Sönmez <[email protected]>:
> Hi, I want to calculate the first four firms share in each industry at
> time t (HHI4 or CH4). I calculated the shares but i cannot sum first four
> firms shares in each industry at time t.
> I tried egen and gen commands with several functions  but they were not
> worked
> Also i did not find any solution or material from stata books and online
> resources
> I have an Unbalanced firm level panel data with variables id, years(t)
> 2003-2006, and 2digitsectors(Sector)and it is in long form
>
> The problem:
> I calculated
> 1stly, total sales of industry j at time t (Yjt)
> 2ndly, share of a firm i in industry j (sales of firm i/Yjt)*100=a
> 3rd a^2 for each firm at time t
>
> 4 step is problematic: I can not calculate shares of first four firms in
> sector j at time t
> like this max(a+a+a+a) by (sector year) and write this value for firms in
> these sector and year
>
> Please help me,
>
> in advance thanks,
>
>
>
>
>
> --
> Alper Sönmez
>
> ODTÜ/METU
> ÝÝBF Ýktisat Bölümü/FEAS Department of Economics
> Ankara Türkiye
> Tel/Phone:0312 210 30 77
> Fax: 0312 210 79 64
>
>
>
>
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
>

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index