# Re: st: How to balance an unbalanced panel data set

 From "Martin Weiss" To Subject Re: st: How to balance an unbalanced panel data set Date Sat, 4 Apr 2009 21:40:55 +0200

```<>

HTH
Martin
_______________________
```
----- Original Message ----- From: "Christian Bustamante" <cdeb77@gmail.com>
```To: <statalist@hsphsun2.harvard.edu>
Sent: Saturday, April 04, 2009 9:37 PM
Subject: Re: st: How to balance an unbalanced panel data set

```
```Still appears  Obs per group: min = 1m. Why?

On Fri, Apr 3, 2009 at 2:18 AM, Martin Weiss <martin.weiss1@gmx.de> wrote:
```
```
<>

So the end result is that you end up with only panel 4? If you throw out
observations due to missingness beforehand, that is the inevitable
conclusion...

*************
clear*

inp year id var1
1998 1 .
1999 1 .
2000 1 34
2001 1 23
2002 1 25
1998 2 56
1999 2 45
2000 2 67
2001 2 47
2002 2 .
1998 3 11
1999 3 13
2000 3 .
2001 3 .
2002 3 23
1998 4 44
1999 4 24
2000 4 33
2001 4 36
2002 4 41
1999 5 24
2000 5 35
2002 5 45
end

drop if mi(var1)

tempvar length
bys id (year): gen `length'=_N
su `length', mean
bys id: drop if `length'!=r(max)
*************

HTH
Martin

-----Ursprüngliche Nachricht-----
Von: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Christian
Bustamante
Gesendet: Freitag, 3. April 2009 04:15
An: statalist@hsphsun2.harvard.edu
Betreff: Re: st: How to balance an unbalanced panel data set

Hi Martin
This is a better example:

---------------
| year id var1|
|---------------|
| 1998 01 . |
| 1999 01 . |
| 2000 01 34 |
| 2001 01 23 |
| 2002 01 25 |
|---------------|
| 1998 02 56 |
| 1999 02 45 |
| 2000 02 67 |
| 2001 02 47 |
| 2002 02 . |
|---------------|
| 1998 03 11 |
| 1999 03 13 |
| 2000 03 . |
| 2001 03 . |
| 2002 03 23 |
|---------------|
| 1998 04 44 |
| 1999 04 24 |
| 2000 04 33 |
| 2001 04 36 |
| 2002 04 41 |
|---------------|
| 1999 05 24 |
| 2000 05 35 |
| 2002 05 45 |
|---------------|

In this example I only want the panel with id 04 with data in all the
years, and drop the panels 01, 02 and 03 with a missing value in at
least one year for var1. I also want to drop the panel 05 with doesn't
have values in all years.

```
On Thu, Apr 2, 2009 at 4:37 PM, Martin Weiss <martin.weiss1@gmx.de> wrote:
```<>

You ought to give a much clearer excerpt of your data.

If it is really as simple as the one below, use -egen myrowmiss,
```
```rowmiss()-
```
```and you can easily drop depending on whether the row has any missings by
-drop if myrowmiss >0 & !mi(myrowmiss)-.

HTH
Martin
_______________________
----- Original Message ----- From: "Christian Bustamante"
```
```<cdeb77@gmail.com>
```
```To: <statalist@hsphsun2.harvard.edu>
Sent: Thursday, April 02, 2009 10:50 PM
Subject: Re: st: How to balance an unbalanced panel data set

```
```Hi and thanks for your response. That's not what I'm looking for. I
will be more explicit.
Supose the folliwing data set with each row represents a panel
observations for a variable:

1 2 3 4 5 6 7 8
. . 3 4 5 6 7 8
1 2 3 . 5 6 7 8
1 2 3 4 5 6 7 .
1 2 3 4 5 . . .

I want to keep only the observations like the first one and drop the
others.

Bests

```
On Thu, Apr 2, 2009 at 3:31 PM, Philipp Rehm <philipp.rehm@gmx.de> wrote:
```
.

http://www.stata.com/support/faqs/data/panel.html

HTH,
Philipp

Christian Bustamante wrote:
```
```
Hi Statalisters,

I have a very unbalanced panel data set, composed for a lot of panel
```
and 12 years. I'm interested in "balance" this panel, keeping only the
```panel tha have information for a set of variables in all the period.
How can I do that?

Thanks

```
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```
```

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