Re: st: Again-Unique Case ID in Large Panel

[Suzy <scott_788@wowway.com>]

above the duplication option is a unique identifier option - that might 
help you.

Stephen V. Burks wrote:


> Hi, Suzy.
>
> OK, if you are correct then both version of -duplicates- agree that I 
> have no
> duplicates. But, this means they both still disagree with -xtdes-, right?
>
> My original starting point was that -xtdes- says I do not have unique 
> identifcation,
> but other approaches (now including both versions of -duplicates-) say 
> that this
> is incorrect, and I should (do) have unique identification.
>
> Is there another misinterpretation on my part buried somewhere here?
>
> Thanks,
> Steve
>
> P.S. just got Nick's post which seems to agree with me, once I accept 
> Suzy's
> interpretation on -duplicates-.
>
> At 12:24 PM 8/4/2004, you wrote:
>
>
> > I believe that your output is saying that you have one copy of  
> > 1322511 with no surpluses (no duplicates). I just ran this yesterday 
> > with my much smaller dataset and was able to verify this.
> > Suzy
> >
> > Stephen V. Burks wrote:
> >
> >
> > > Hi, Folks.
> > >
> > > Now I wonder if I am reporting a bug.  As per Nick's suggestion
> > > (thanks, Nick) I looked up -duplicates- and ran it.
> > >
> > > Results:
> > > (1) using -duplicates report-
> > >
> > > . duplicates report  DRVNUM  CDATE
> > >
> > > Duplicates in terms of DRVNUM CDATE
> > > --------------------------------------
> > >    copies | observations       surplus
> > > ----------+---------------------------
> > >         1 |      1322511             0
> > > --------------------------------------
> > >
> > > (2) using -duplicates list-
> > >
> > > . duplicates list  DRVNUM  CDATE
> > > Duplicates in terms of DRVNUM CDATE
> > > (0 observations are duplicates)
> > >
> > >
> > > If I read this correctly, one version of -duplicates- says I have
> > > a single duplicate (the last case in the file), while the other
> > > says I have none. Also, -xtdes- still says that DRVNUM and
> > > CDATE do not uniquely identify cases.
> > >
> > > I looked in the data browser, and the last case is NOT a duplicate.
> > > While DRVNUM is the same as the case before, CDATE is not.
> > >
> > > If my interpretation of the output is correct then my best guess is
> > > that -xtdes- is wrong to say I do not have unique identification,
> > > and whatever bug causes this might also be behind the apparently
> > > incorrect response from -duplicates report-.  In any event, it seems
> > > to be a problem that -duplicates list- and -xtdes- do not agree.
> > >
> > > Any better ideas?
> > >
> > > Thanks,
> > > Steve
> > >
> > > P.S. My version of Stata is 8.2 for WinXP, with current updates.
> > >
> > > --------------------------------------------------
> > > *Stephen V. Burks, Ph.D.
> > > *Assistant Professor of Economics and Management
> > > *University of Minnesota, Morris
> > > *
> > > *Division of Social Sciences
> > > *600 East 4th Street
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>
>
> --------------------------------------------------
> *Stephen V. Burks, Ph.D.
> *Assistant Professor of Economics and Management
> *University of Minnesota, Morris
> *
> *Division of Social Sciences
> *600 East 4th Street
> *Morris, MN 56267-2134
> *
> *Voice: (320) 589-6191
> *Division Staff: (320) 589-6200
> *FAX: (320) 589-6117
> *E-Mail:  svburks@mrs.umn.edu
> *
> * "Striving to be the Best National
> *  Public Liberal Arts College in the U.S."
> --------------------------------------------------- 
> *
> *   For searches and help try:
> *   http://www.stata.com/support/faqs/res/findit.html
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/