Using global for varlist

[Sergi Quintana]

Hey!

I am declaring a global macro with a list of variables to do a loop, and then keep only those variables. While the global option is working on the loop, it is not working with the keep command. Any ideas why?

 global variables risk_general risk_driving risk_finances 
foreach var of global variables {
gen `var' = `var'_2010 if `var'_2010 >= 0 
replace `var' = `var'_2011 if `var'_2011 >= 0
}

keep `variables'

The error I am getting is:

varlist, if exp, or in range required

Which I assume Stata is not understanding that my global `variables' is a varilist. What am I doing wrong?

Thanks!!

[Nick Cox]

I can't see a problem here with your code, but watch out: missing values count as greater than zero.

[Sergi Quintana]

Thanks Nick. This is wierd. I know, in my case missing values are coded as negative numbers. Thanks for the help!

[Nick Cox]

So, that is not an issue. Here's a different question: Are you running the code all at once, or line by line from a do-file editor window? If the second. then the definition of var will not be visible when you refer to it. The code could be

f

oreach var in general risk finances { 
     gen risk_`var' = risk_`var'_2010 if risk_`var'_2010 >= 0 
     replace risk_`var' = risk_`var'_2011 if risk_`var'_2011 >= 0 
}

but must be run as a whole, not line by line.

I find it hard to imagine that you should keep only these variables.

[Mike Lacy]

Regarding the original code fragment: Because -variables- is a global and not a local, shouldn't the last line be

keep $variables

[Nick Cox]

@Mlke Lacy is quite right. This would be an explanation of the error message. But do you really want to get rid of everything else?

[Sergi Quintana]

Thanks for the answers!