Re: st: problem in ICE for multiple imputation

[Craig Anderson <clanders@uci.edu>]

a
In a complicated imputation, I found it helpful to check each  
regression separately before running ICE.  If it's not obvious from 2- 
way tabs where the problem is, you could even run ologit or mlogit  
with one independent variable and then add one variable at a time to  
see which one is preventing convergence.

Craig

On Jul 11, 2007, at 11:00 PM, Maarten buis wrote:


> --- tang5@purdue.edu wrote:
> > A survey dataset has four variables q098 q099_2, q100 and 130 with a
> > heavy amount of missing values for each of them.
> > I ran the ice command and get the following message:
> >
> > "I detected a problem with running uvis with command mlogit on
> > response q098 and covariates q099_2 q100 q130.
> >
> > The offending command resembled:
> > uvis mlogit q098 q099_2 q100 q130 ,
> >
> > With mlogit, try combining categories of q098, or if appropriate, use
> > ologit
> >
> > unrecognized command
> > r(199);"
> >
> > Then I use the option cmd(q098:ologit) since that variable could be
> > an ordinal variable. I got the following message:
> > "I detected a problem with running uvis with command ologit on
> > response q098 and covariates q099_2 q100 q130.
> >
> > The offending command resembled:
> > uvis ologit q098 q099_2 q100 q130 ,
> >
> > unrecognized command"
> Try combining some of the categories, like I virtualy always do when I
> use rep78 in my examples:
> http://home.fsw.vu.nl/m.buis/stata/exampleFAQ.html#recode .
>
> -mlogit- and -ologit- somtimes won't converge if one of categories is
> very small. More seriously, the algorithm underlying -ice- (a Gibbs
> sampler) won't converge if another variable or variables have all
> missings for one value of q098. This is serious as -ice- will not and
> cannot automatically check for convergance. I got the impression that
> Patrick now checks for these problems and issues this warning message.
>
> Hope this helps,
> Maarten
>
> -----------------------------------------
> Maarten L. Buis
> Department of Social Research Methodology
> Vrije Universiteit Amsterdam
> Boelelaan 1081
> 1081 HV Amsterdam
> The Netherlands
>
> visiting address:
> Buitenveldertselaan 3 (Metropolitan), room Z434
>
> +31 20 5986715
>
> http://home.fsw.vu.nl/m.buis/
> -----------------------------------------
>
>
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