Dear Friends,
thank you very much. I have not tried what Stas
suggested yet because I still haven't defined my
panelid (I am still doing some data cleaning but I ask
my question ahead of time).
I mean variables not observations.
But now that you are talking about obs, I have another
question:
when I create the panel, I assign an id to each
individual, but as we move through years, the number
of obs decreases so I cannot assign the same panelid
so how do we treat the missing observation?
Thanks for your help
Feno
--- Rose Medeiros <[email protected]> wrote:
> To me at least, the author seems to mean "variables"
> rather than
> "observations." Since she states that questions were
> asked at one wave,
> but not at the others. Her example, religion, is
> often presumed to be
> time invariant (i.e. people don't change their
> religions often), so it
> would make sense that it would only be asked at one
> point. It might be
> useful to know whether the "problem" variables are
> all of this sort or not.
> Rose
>
> Nick Cox wrote:
>
> >This answer takes Nirina to mean "observations"
> >when she says "variables". I did wonder this
> >myself, but it is not what she said.
> >
> >Nick
> >[email protected]
> >
> >Stas Kolenikov
> >
> >
> >
> >>Depends on what you want to do with them. You can
> -drop- them, or you
> >>can fill them in by
> >>
> >>sort panelid time
> >>unab allvars : *
> >>foreach x in varlist `allvars' {
> >> bysort panelid (time): replace x=x[_n-1] if
> mi(x)
> >>}
> >>This may lead to some awkward results, and
> sometimes the missing value
> >>is a valid one (e.g. a wage of somebody who was
> employed in the first
> >>period, but not in the second one), so if you know
> the variables you
> >>want to fill in by the prior values, you should
> put them as the
> >>varlist in -foreach- above.
> >>
> >>
> >
> >Nirina M.
> >
> >
> >
> >>>my question should be very easy but forgive my
> >>>d..ness.
> >>>I am creating a panel data but the trouble now is
> that
> >>>there are variables that exist in the start of
> the
> >>>survey but does not exist in the following
> year:(or
> >>>sometimes new questions come up in the following
> year
> >>>but were not asked before): say the religion,
> they ask
> >>>it in 98 but not later.
> >>>
> >>>
> >
> >*
> >* For searches and help try:
> >*
> http://www.stata.com/support/faqs/res/findit.html
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> >
> >
> >
>
> *
> * For searches and help try:
> *
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>
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