Re: st: How to drop observations in panel

[Islam Abdeljawad <islamabdeljawad@yahoo.com>]

It works. will check if i should use it in my regression. Thanks Nick

 



----- Original Message -----
> From: Nick Cox <njcoxstata@gmail.com>
> To: statalist@hsphsun2.harvard.edu
> Cc: 
> Sent: Saturday, August 6, 2011 4:16 PM
> Subject: Re: st: How to drop observations in panel
> 
> bysort panelid : drop if _N < 3
> 
> Whether this is a good idea is a different matter.
> 
> Nick
> 
> On Sat, Aug 6, 2011 at 6:36 AM, Islam Abdeljawad
> <islamabdeljawad@yahoo.com> wrote:
> 
>>  I am new to stata. I am working on an unbalanced data set where firm is the 
> cross section identifier
>>   and the time identifier is year.
>>  Estimation of the model will be based
>>   on GMM-sys. some of my firms have only one or two years of observations.
>>  Should I drop these firms and how I can do it in stata. in other words, any 
> firm
>>   that have less than three years of data
>>  available (less than three observations) will not be included in the 
> estimation.
> 
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