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Re: st: Averages for missing values
These methods are frowned upon? Which method in particular is the object
of the frown? I guess I am puzzled, because mean substitution comes in a
few flavors. There is substituting the mean and leaving it at that. I
assume this is widely understood as problematic. And then there is
substituting the mean and adding a dummy variable to the model that
indicates whether the mean has been substituted. Is there any problem
with this second approach?
Thanks a bunch.
On Thu, 8 Sep 2005, Richard Williams wrote:
> At 03:45 PM 9/8/2005, TinnaLaufey Asgeirsdottir wrote:
> >Hello Statalist.
> >Before I give myself carpal tunnel syndrome I might ask:
> >Is there a command to replace missing values with averages?
> >What I am currently doing is:
> >generate varnameAVE=varname
> >summarize varnameAVE
> >replace varnameAVE=[here I use the mouse to copy from the results
> >window to the command window] if varnameAVE==.
> Adding to your list of suggestions: try the -impute- command, e.g.
> gen one = 1
> impute varname one, gen(varnameAVE)
> For other variations (e.g. subgroup means) see p. 10 and later of
> Let me add that this may be showing you how to do evil, however; most
> of these sorts of methods are now frowned upon. See Paul Allison's
> Sage book entitled "Missing Data". You may wish to check out Patrick
> Royston's -ice- package, which is also discussed in Stata Journal, V.
> 5 # 2, pp. 188-201.
> Richard Williams, Notre Dame Dept of Sociology
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