How to create new variables combining strings from two other columns?

[Claudia Gerber]

Hi,

I am looking to create a new string variable that combines names from two different columns (also strings). This is what it looks like.

HH_Head1	HH_Head2	New Variable (combined name list)
Anna	.	Anna
John	.	John
.	Henry	Henry
.	Paul	Paul
Sam	.	Sam
.	Lucy	Lucy

Basically, I want to know how I can create the combined name list by using the names from HH_Head1 and HH_Head2.

Thanks so much in advance for your help!

Best, Claudia

[Carole J. Wilson]

sure:

gen new_var=HH_Head1 + HH_Head2

*or

gen new_var2=HH_Head1
replace new_var2=HH_Head2 if mi(HH_Head1)

[eric_a_booth]

If what you really want is a new variable that is HH_head1 if that is not missing and HH_head2 if that is not missing (and the conditions always mutually exclusive) then you can use:

gen newvar = cond(!mi(HH_Head1) & mi(HH_Head2), HH_Head1, HH_Head2)

or you can just combine strings with:

g newvar2 = HH_Head1 + HH_Head2

if the missing values you show (".") are actually just "" .

[Nick Cox]

The most general workhorse here is the concat() function of egen.

It allows, beyond the other commands in previous answers,

* numeric to string conversions on the fly, including using value labels and/or specified display formats

* different separators, such as spaces or commas.

[Claudia Gerber]

Thanks everyone! Very helpful!