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Re: st: gllamm with pweights


From   Stas Kolenikov <skolenik@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: gllamm with pweights
Date   Wed, 15 Jul 2009 19:14:46 -0500

With just two values of the second level variable, you won't get any
sensible results.  I'd suggest modeling this with fixed effects of
urban/rural location and interaction with other variables, where
applicable.

Couple points on the data set up: if you don't have the second level
weights, you should assume they are equal to 1. Also, -collapse- with
a -merge- is an overkill, you could get the sum of weights by

egen sum_of_weights = sum( weight )

Of course the first comment is the more important one than these two :)).

On Wed, Jul 15, 2009 at 5:37 PM, Kanter, Rebecca<rkanter@jhsph.edu> wrote:
> Hi,
>
> I am running 2 level multi-level models using gllamm. Level one is individuals and Level two is either the urban or rural part of the country's state (i.e. urstate).
>
> I would like to use the survey pweights I have...I only have pweights for the individual level (adul_sr), but it seems that you need pweights for all levels specified in gllamm (?) so this is what I did to create pweights for urstate based on these weights:
>
> collapse (sum)  sadul_sr=adul_sr , by(urstate)
>
> then I merged them to the rest of my dataset
>
> and made this weight for the gllamm:
>
> *MLM-level pweights
> generate pwadulsr1=adul_sr
> *urstate summed adul_sr
> generate pwadulsr2=sadul_sr
>
> Then ran the most basic random-intercept only (around urstate) in gllamm and get the follow error below and am assuming it is a pweight problem but I do not know where the problem is coming from so if anyone has insight that would be much appreciated. Thanks so much!
>
> (note: diettag==1 & exwt==1 is the subpopulation i want to look at for this series of models)
>
> gllamm bmi2 if diettag==1 & exwt==1, i(urstate) pweight(pwadulsr) adapt nip(15)
>
> Running adaptive quadrature
>
> Convergence not achieved: try with more quadrature points
>
>
> ___________________________________________
> Rebecca M. Kanter
> PhD Candidate
> Johns Hopkins Bloomberg School of Public Health
> Department of International Health
> Center for Human Nutrition
>
> *
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>



-- 
Stas Kolenikov, also found at http://stas.kolenikov.name
Small print: I use this email account for mailing lists only.

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