Re: st: RE: endogeneous switching regression with movestay-ado: error after margins command

[Stephani Jens <Jens.Stephani@iab.de>]

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Thank you Nick,

you are probably right concerning the use of the term "bug".

Regarding your other suggestion, I already tried that before
posting to statalist (i.e. using -if- and making -margins-
conditional on the non-missing observations; it gave me
another error message, “prediction is a function of possibly
stochastic quantities other than e(b)”.

When using -mfx- instead of -margins-, Stata gives another
error message telling that it did not find the variable y0
(or y1, respectively).

So I was wondering if somebody else is working with -movestay-
and might be able to give me a hint.

Thanks
Jens

>Date: Wed, 18 Jan 2012 14:01:40 +0000
>From: Nick Cox <n.j.cox@durham.ac.uk>
>Subject: st: RE: endogeneous switching regression with movestay-ado:
>error after margins command
>
>I wouldn't cry "bug" before I was pretty certain, meaning I have
>looked at some code and I am convinced it is wrong. A program not
>behaving in the way you hope is not ipso facto evidence of a bug.
>
>- -margins- was introduced in Stata 11. -movestay- was written for
>Stata 8, which does not rule out it being compatible with -margins-,
>but certainly means that the authors could not be expected to be
>presciently aware of how it meshes with -margins-.
>
>At a wild guess, this may be soluble by making your -margins- call
>conditional on there being non-missing predictions, using -if-.
>
>Nick
>n.j.cox@durham.ac.uk
>
>
>
>
Date: Wed, 18 Jan 2012 09:46:17 +0000
From: Stephani Jens <Jens.Stephani@iab.de>
Subject: st: endogeneous switching regression with movestay-ado: error after margins command

>Dear Statalist members,>
>I am using the ado-file by Lokshin/Sajaia 2004 called movestay (Stata
>Journal 4, No. 3) to estimate an endogenous switching regression.
>After estimation, I want to use the margins command to calculate the
>marginal effects in the outcome equations (conditional on being
>observed in that equation) Unfortunately, I get an error message
>saying " missing predicted values encountered within the estimation
>sample r(322)". It seems to me that this is a bug.
>
>Here is my code:
>
>movestay (y $a), select(var1 $a $s) cluster(idnum)
>
>** output omitted **
>
>margins, dydx($a) atmeans predict(yc1_1)
>
>Warning: cannot perform check for estimable functions.
>missing predicted values encountered within the estimation sample
>r(322);
>
>Does anybody have an idea what the problem might be?
>Any help will be greatly appreciated.
>
>
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