How do we extend an unbalanced panel to a balanced monthly panel?

[Zoey Zhang]

Hi~ I have a question about extending a unbalanced panel into a balanced monthly panel:

I have a panel data which have a structure looks like the following:

id	starting date	ending date	monthly wage
001	19990101	19990115	400
001	19990116	19990605	800
001	19990606	19991031	1000

Different individuals may have different numbers of records. Therefore it's an unbalanced panel.

I need to construct a balanced monthly panel out of the above information. More precisely, I need a data structure looks like the following:

id	year	month	monthly wage
001	1999	1	400+800
001	1999	2	800
001	1999	3	800
001	1999	4	800
001	1999	5	800
001	1999	6	800+1000
001	1999	7	1000
001	1999	8	1000
001	1999	9	1000
001	1999	10	1000
001	1999	11	0
001	1999	12	0

Note that: (1) in month 1 and 6, there are multiple wage records and I need to sum up the wages for these months. (2) For month 11 and 12, there is no records, so the wage is 0.


I have no idea how to create such a balanced panel with STATA. Could anyone give some advice? Your help is very much appreciated !

[Carlo Lazzaro]

Zoey:
welcome to the list.
The advice is: don't do it, for two reasons:
- attrition in your datset might be informative (and you should investigate it first);
- Stata (not STATA, please) can handle both balanced and unbalanced panel datasets with no problem.

[Zoey Zhang]

Zoey:
welcome to the list.
The advice is: don't do it, for two reasons:
- attrition in your datset might be informative (and you should investigate it first);
- Stata (not STATA, please) can handle both balanced and unbalanced panel datasets with no problem.

Dear Carlo,
Thank you very much for your timely response and kind reminder!~ It's very much appreciated!
I think I have to create such a panel because I need to create a plot of wages over months... Is there any Stata command or code to support that?


Best,

[Carlo Lazzaro]

Zoey:
the no-frills code might be:

. use "http://www.stata-press.com/data/r15/nlswork.dta"

. histogram ln_wage, by(year)

[Zoey Zhang]

Zoey:
the no-frills code might be:

. use "http://www.stata-press.com/data/r15/nlswork.dta"

. histogram ln_wage, by(year)

Dear Carlo,

Thank you for your reply~
Sorry that I did not make my question clear enough~ I mean is there any Stata command or code that might be helpful to extend panel?

Best,

[Carlo Lazzaro]

Zoey:
see -expand-.

[Zoey Zhang]

Zoey:
see -expand-.

Thank you a lot! That's what I'm looking for~

Best,