Hi all,
I do not have a licence for stata to combine the imputations for amelia. I have thought about using an aggregate function in SPSS to generate means and standard deviations for cases across all the five files (My gut instinct is that this is way too simple). I have also thought about using NORM to combine the five file parameters (Again seems to simple). Any advice on how to combine the amelia data files without stata would be much appreciated.
Kind regards Paul
Hi,
would anyone be able to help with a longitudinal, cross national dataset?
My full model contains 90 countries observed on 18 variables for 10
years - but missing cases reduce the model to 71 countries. Is there a
way to make multiple imputation work? Amelia goes
through all the steps but the last one, returing an error message saying
that "columns don't match." Is the dataset simply too large? I have tried
the options for TSCS data without specifying country or time dummies, but
the procedure still stops. Any help would be truly appreciated!
Simone Polillo
On Sat, 15 Nov 2003, Paul Miller wrote:
> Dear Dr. King,
> I'm currently using multiple imputation to deal with missing
> observations in an analysis I'm conducting. I want to combine the
> f-tests associated with each of my imputations but it's not clear how I
> should do so. Is there any way that a non-statistician such as myself
> could go about combining these results?
>
> Paul
if the f-test is really your quantity of interest, you could use the same
rules as combining any other quantity (see our article for a description;
the point estimate is simply an average of the separate estimates).
However, most likely the f-test is actually being used as a test of some
kind and you have another quantity of interest, such as a first differnce,
or regression coefficient. In all likelihood, you have one of these, and
I'd suggest that you compute it, following the rules for combining
separate quantities of interest.
If you have a more complicated case with multiple quantities of interest,
i would consider combining the simulations from each of the analyses of
the imputed datasets.
Best of luck with your research,
Gary
: Gary King, King(a)Harvard.Edu http://GKing.Harvard.Edu :
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