How to make exclusion-group from several variables?

[Lars Andersson]

Hello!
I am new to STATA, so this is definitely a question regarding user error, and may seem trivial.
I want to group together several variables, and only include ID:s if the have a value in each of those variables. In other words I'm trying to make an exclusion of ID:s that are missing data in any of the variables.
I have tried to do this in several ways, for example:
gen group =1 if varname1 <. & varname2 <. & varname3 <.

Have a nice day!
//Lars

[Clyde Schechter]

Well if you want to eliminate all observations that have a missing value for varname1, varname2, or varname 3, the simplest way is just

keep if !missing(varname1, varname2, varname3)

If you don't want to eliminate the variables, but just mark them for exclusion from later calculations, you can do that with

gen byte exclude = missing(varname1, varname2, varname3)
...
whatever if !exclude

I should point out, however, that this may be unnecessary. Most Stata commands will automatically exclude any observations that has a missing value for any variable that is mentioned in the command.

[Lars Andersson]

Thank you!
This helped a lot. Have a great weekend!
//Lars