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Re: st: -predict- in a system of equations


From   Ada Ma <pec187@abdn.ac.uk>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: -predict- in a system of equations
Date   Sat, 22 May 2004 17:52:04 +0100

Hi Rafa,

I'm going to make another rustic suggestion after reading your email to Michael Blasnik, again it might not be of much use. My suggestion is:

How about if you -append- data1.dta and data2.dta? (And plug in a dummy in data2.dta before you -append-.)

Hope it helps.
Ada



R.E. De Hoyos wrote:

Michael,

Thanks for your answer.

-predict- wont work because several equations are being estimated. Suppose I
estimate -heckman- using data1.dta, then a vector e(b) is created in
which -predict- is based on. Once a second equation is estimated,
e.g. -mlogit- a new vector is created, let's say to e(b') and the old one is
being lost. When I change to data2.dta I want to be able to predict (or
score) using both e(b) and e(b'), therefore I needed a way to save these
vectors, which your suggestion is doing very well.

It would be quite useful to have an option to save all the -predict-
properties (at least temporary) to use them in an alternative dataset.
With -matrix score- I can only form linear combinations of the previously
saved vectors e(b)s and the new Xs, while I might be more interested in the
fitted probabilities (as in the case of limited dependant variables eq.)

Thanks again,

Rafa


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