Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
st: RE: Unbalancing a panel data set with country pairs
From
Nick Cox <[email protected]>
To
"'[email protected]'" <[email protected]>
Subject
st: RE: Unbalancing a panel data set with country pairs
Date
Fri, 21 Jan 2011 13:39:48 +0000
I assume that "country pair" defines a panel identifier.
Look at the help for -egen-, which gives you one way to start.
In terms of missings,
egen missing_in_obs = rowmiss(varlist)
egen missing_in_panel = total(missing_in_obs), by(panelid)
drop if missing_in_panel
In terms of not enough years, you don't quite say what the time resolution of your data is. But assuming you have yearly observations then
bysort panelid : drop if _N < 17
drops the short panels. If it's half-years, quarters, months, etc. adjust as needed.
You need to plug in your own <varlist> and <panelid>.
The big concept you appear to be missing is that of working -by:-. There is a tutorial at
SJ-2-1 pr0004 . . . . . . . . . . Speaking Stata: How to move step by: step
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox
Q1/02 SJ 2(1):86--102 (no commands)
explains the use of the by varlist : construct to tackle
a variety of problems with group structure, ranging from
simple calculations for each of several groups to more
advanced manipulations that use the built-in _n and _N
Nick
[email protected]
Matei Frunzetti
I 'm working on a panel data set over 17 years. It's fairly unbalanced
und i need to drop all observations for country pairs that either lack
full length (as in years) or have missings in one of the independant
variables. The problem is that i have to delete all observations of
these country pairs for all years if only one or more variables have a
missing or if it is one or more years short. I ran into a dead end
trying to figure out how to imply the rest of the observations of a
"faulty" country pair into the drop command.
*
* 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/