Re: st: RE: Attrition question...

[David Torres <torresd@umich.edu>]

Thanks for the tip...worked wonderfully.

D
--
David Diego Torres, MA(Sociology)
PhD Candidate in Sociology

2044 Population Studies Center
University of Michigan Institute for Social Research
Ann Arbor MI  48106-1248
Tel 734.763.4098
Fax 734.763.1428
torresd at umich dot edu


Quoting Nick Cox <n.j.cox@durham.ac.uk>:

> A solution follows by analogy with an FAQ:
>
> FAQ     . . . . . . . . . . . . . . . . . .  Dropping spells of  
> missing values
>         . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox and  
> G. Longton
>         3/07    How can I drop spells of missing values at the
>                 beginning and end of panel data?
>                 http://www.stata.com/support/faqs/data/dropmiss.html
>
> See its section 5 in particular.
>
> I assume panel identifier -id- and time variable -time- and that the  
> variable -interviewed- is a string variable.
>
> gsort id -time
> by id : drop if sum(interviewed  == "y") == 0
>
> Alternatively, assume that -interviewed- is an indicator variable 1  
> for interviewed and 0 for not. The second line becomes
>
> . by id: drop if sum(interviewed) == 0
>
> Although your posting does not explain some key features of your  
> dataset, you should be able to modify solutions like this after  
> study of the FAQ.
>
> On the other hand, I don't understand where the -reshape wide- idea  
> comes from. Datasets like this are best kept long. Also, I don't  
> know what IPTW weights are.
>
> Nick
> n.j.cox@durham.ac.uk
>
> David Diego Torres, MA(Sociology) PhD Candidate in Sociology
>
> I have a longitudinal file on which I just completed multiple
> imputation.  It has been reshaped to long format.  I need to cycle
> through each case and drop all instances for which someone was missing
> in a round and was never interviewed again up to the most recent
> survey round.  Is there a quick and easy way to do this?
>
> For a case like this:
>
> id     interviewed?     ...      ...
>
> 1           y
> 1           n
> 1           y
> 1           y
> 1           y
> 1           n
> 1           n
> 1           n
> 1           n
>
> I would like to drop all information from round six on.
>
> The purpose is to drop the fully attrited cases, then reshape wide,
> then back to long.  Then I can calculate IPTW weights.
>
>
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