Generate variable from other individual's id

[Marta Oliveira]

Dear Stata users,
I am using the German Socio-economic panel data. I am using the following variables: persnr (which is the id of the individual), fatherpersnr (which is the father id of the individual, in this panel data some of the people surveyed in the household are parents and children) and birthcountry.
I would like to generate a new variable: fatherbirthcountry. I have been thinking on a strategy to solve this but nothing came to my mind. Could anyone please give me some help?
Thank you!

[Carlo Lazzaro]

Marta:
wouldn't -egen- with the -group- function be an option?

[Marta Oliveira]

Thank you, Carlo Lazzaro for your answer; but I am still not seeing how it can work.
I will give an example to make my situation clearer:

persnr	fatherpersnr	birthcountry
1 2 3	. 1 .	US UK Germany

and I want to obtain

persnr	fatherpersnr	birthcountry	fatherbirthcountry
1 2 3	. 1 .	US UK Germany	. US .

[Carole J. Wilson]

In the future, please post data using the -dataex- command (see FAQ 12.2--https://www.statalist.org/forums/help#stata)

Here's an example:

* Example generated by -dataex-. To install: ssc install dataex
clear
input float(persnr fatherpersnr) str7 birthcountry
1 . "US"     
2 1 "UK"     
3 . "Germany"
4 . "Mexico"
5 . "Brazil"
6 4 "France"
end

I think, the following code will give you what you want:

preserve
keep persnr birthcountry
rename persnr fatherpersnr
rename birthcountry fatherbirthcountry
save father_info.dta, replace
restore
merge m:1 fatherpersnr using father_info.dta
drop if _merge==2
sort persnr