No variables defined

[Gudlaug Olafsdottir]

Hi!

I'm new to both Stata and forums - hoping to get some assistance here, would be very greatful. I'm trying to merge a dataset into a "master dataset". My problem is that although it works for other datasets, there is one that receives the error message "no variables defined". This is the only one for which I am trying to use the command "merge m:1 var1 var2 using "location.dta" , assert(match master)" since I only want to keep those observations that match my original dataset.

Why do I get this error message and what can I do to fix it?

Many thanks for the help!!

/G

[Gudlaug Olafsdottir]

Now I removed clear at the top of my do-file, instead I'm getting the error message "_merge already defined"

[Carlo Lazzaro]

Gudlaug:
you should remove -_merge- variable from the master file you're working on.

[Gudlaug Olafsdottir]

Thanks so much! That did work!