st: Re: Herfindahl index

["R.E. De Hoyos" <redeho@hotmail.com>]

Dawood,

bys repdte state: egen sum = sum(asset)
generate share = (assets/sum)*100
bys repdte state: egen HERF = sum(share)

Rafa


----- Original Message ----- 
From: "Dawood Ashraf" <abpe1a@bangor.ac.uk>
To: <statalist@hsphsun2.harvard.edu>
Sent: Monday, July 11, 2005 6:34 PM
Subject: st: Herfindahl index



> Hi statalist
>
> I am trying to calculate degree of concentration in an industry by using 
> the
> Herfindahl index.  I am using the panel data where I have 10 years of 
> time, 50
> states, in every state there are a few companies. I am using the following
> command
>
> bysort  state: generate HERF= (asset/ sum(asset))^2 if repdte==1997
>
> The resulting output use the running sum in the denominator instead of sum 
> of
> asset of all companies for year 1997.
>
> Could any one tell me how can I implement The Herfindahl index in stata in 
> this
> situation?
>
> regards
>
>
>
> --
> Dawood Ashraf
>
>
> --
> This mail sent through http://webmail.bangor.ac.uk
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