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Re: st: Re: loop to fill in missing observations
Dear Chuntao,
Thank you very much for the suggestion. I do not think this will work.
First, I do not need four observations for each country-year: I just
need new observations for country-years that are not included in the
original dataset. Second, the fillin command creates all logical
combinations of variables, but does not create values that do not
exist in the original dataset, which is what I need.
If I understand your suggestion correctly, it will not solve my problem.
Thanks for your help,
Fabrizio
On 15 Jun 2007, at 16:48, Li Chuntao wrote:
Dear Fabrizio,
As you need four observations for each country and year, you can
turn the year and election to a quarter variable, that is, treat
the first obs for each year as spring and the second as summer.
then you have two variables to identify each election, that is,
country and season.
then you can use the fillin command in stata.
suppose you have the following data, where X is the variable to be
the same with the previous observation
country season x
1 1 1
1 2 4
2 1 5
2 2 8
2 3 10
3 1 4
4 1 3
4 2 5
fillin country season
then u got the following data
country season x _fillin
1 1 1 0
1 2 4 0
1 3 . 1
2 1 5 0
2 2 8 0
2 3 10 0
3 1 4 0
3 2 . 1
3 3 . 1
4 1 3 0
4 2 5 0
4 3 . 1
is this what you need?
Cheers
Chuntao
----- Original Message ----- From: "Fabrizio Gilardi"
<[email protected]>
To: <[email protected]>
Sent: Friday, June 15, 2007 10:25 PM
Subject: st: loop to fill in missing observations
Dear Statalist,
I have a dataset of national elections in 28 countries.
Observations are elections. This means that there can be several
elections in the same year, and on the other hand only years when
an election was held are included in the dataset.
I want to fill in missing years for each country. My idea was to
loop over countries and years to check for every country if a
given year is present, and if not fill it in. To do so, I have
created an appropriate number of missing observations to be
filled in, and a counter variable to identify them.
Concretely, the dataset looks like this:
countryn year elecn fillin
1 1990 1 .
1 1994 2 .
1 1994 3 .
1 1997 4 .
2 1989 1 .
2 1992 2 .
2 1995 3 .
2 1999 4 .
2 2000 5 .
. . . 1
. . . 2
. . . 3
And my code is the following:
g n=.
local z=1
qui forval x=1/28 {
forval y=1975/2002 {
sum year if year==`y' & countryn==`x'
replace n=r(N)
replace year=`y' if n==0 & fillin==`z'
replace countryn=`x' if n==0 & fillin==`z'
count if countryn==`x' & year==`y' & fillin==`z'
local w=r(N)
local z=`z'+`w'
}
}
Now, for some countries it works fine, but for most some missing
years are not filled in. It does not seem to depend on whether in
the country there was more than one election in some year, and I
cannot find any pattern that could help me identify the problem.
What am I doing wrong?
Many thanks in advance,
Fabrizio
------------------------------------------------------------
Fabrizio Gilardi, PhD
Institut d'Etudes Politiques et Internationales
Universit� de Lausanne
B�timent Anthropole
CH-1015 Lausanne
Switzerland
Phone +41 21 692 31 48
Fax + 41 21 692 31 45
[email protected]
http://wwwpeople.unil.ch/fabrizio.gilardi/
------------------------------------------------------------
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------------------------------------------------------------
Fabrizio Gilardi, PhD
Institut d'Etudes Politiques et Internationales
Universit� de Lausanne
B�timent Anthropole
CH-1015 Lausanne
Switzerland
Phone +41 21 692 31 48
Fax + 41 21 692 31 45
[email protected]
http://wwwpeople.unil.ch/fabrizio.gilardi/
------------------------------------------------------------
*
* 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/
