I have a pressing question:
let's say I have an amount of respondents (1000) with unique ID codes in small dataset A.
I want to merge variables at hand of these ID codes from dataset B. IN this dataset, there are approximately 50.000.000 cases (1000 of these ID's are equal to the respondents in dataset A).
How can I merge the relevant variables to the 1000 individuals without getting all the 50.000.000 cases?
It would be awesome if somebody could help me out!