Kyle Hood <kyle.hood@yale.edu> has discovered a bug in -predict- after
-mlogit-. He writes:
> I am trying to do predictions of scores with mlogits, and I get some
> strange errors. Using Stata 10. Here is an example.
>
> . webuse sysdsn3
>
> . mlogit insure age male nonwhite site2 site3
> * results suppressed *
>
> . predict s1 s2 s3, scores
> too many variables specified
> the current estimation results for mlogit have 2 equations so you
> must
> specify 2 new variables, or you can use the
> equation() option and specify one variable at a time
> r(103);
>
> . predict s1 s2, scores
> too few variables specified
> insure has 3 outcomes and so you must specify 3 new variables, or
> you can use the outcome() option and specify variables one at a time
> r(102);
>
> How can 3 be too many but 2 too few? What am I missing, here?
There is a bug in the -mlogit- predictor regarding how it is matching the
number of explicitly-stated variables to the number of model equations. This
will be fixed in the next ado update. As a temporary workaround, Kyle can use
wildcards, as Maarten Buis <maartenbuis@yahoo.co.uk> has already suggested:
. predict s*, scores
will automatically generate the correct number of new variables.
--Bobby
rgutierrez@stata.com
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