Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down at the end of May, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: RE: Spotting changes in identifier


From   "Pavlos C. Symeou" <p.symeou@lmu.de>
To   "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu>
Subject   Re: st: RE: Spotting changes in identifier
Date   Wed, 07 Jul 2010 14:05:50 +0200

thanks for the reply. As you suggest I omit the "" but what the new command returns is the last year-observation for all companies in my dataset.

Is there a possible explanation for that?

Best,

Pavlos



On 07/07/2010 13:12, Nick Cox wrote:
You tried

bysort name: l name ticker year if ticker[_n]!="ticker[_n+1]"

but you need to omit the " ". What you typed is legal, but the literal text

"ticker[_n+1]"

presumably never is an actual value of -ticker-, so this will list all the data, as every value of ticker is indeed not equal to that text.

As said, omit the "".

Nick
n.j.cox@durham.ac.uk

Pavlos C. Symeou

I have panel data on a number of companies over a series of years.
Two of my variables uniquely identify an observation (Name and
Ticker). For different reasons:
a) the Name may have changed over the years whilst the Ticker may
have remained the same;
year      name   ticker
1999    stata   ss
2000    strata ss

b) the Ticker may have changed over the years whilst Name may have
remained the same;
year      name   ticker
1999    stata   ss
2000    stata   sss

c) both may have changed

year      name   ticker
1999    stata   ss
2000    strata sss


I am interested in identifying cases a) and b) above (considering
that case c might require visual observation rather than an
automated process)

Do you have any suggestions?

I have tried

bysort name: l name ticker year if ticker[_n]!="ticker[_n+1]"

but it doesn't seem to work. Both Name and Ticker are string variables.


*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index