How to make a unique identifier when working with World Bank Living Standards Measurement Survey

[Maria Correa]

Hello!
I am trying to merge two sections of a household questionnaire together in stata, and these questionnaires come from the Uganda 2018-19 Living Standards Measurement Survey - ISA. I can't merge them together because I get an error code in stata saying "variable hhid does not uniquely identify observations in the master data". I used the merge 1:m code in my attempt to merge. How would I create a unique identifier so that I could merge these data sets together?
Thank you!

[George Ford]

Sounds like you have multiple people within a household. There's a variable pid that measures the person, so try the merge on both hhid and pid.

Also, use joinby and not merge.

[Maria Correa]

thank you! what is the difference between merge and join by?

[George Ford]

joinby is better, in my experience. you can control what type of match of you get using the "unmatched" option and you get a _merge variable that tells you how it sent. And Stata's merge has issues in the m:m case.