In a previous place I worked we had "North Africa and Middle East" and "Sub-sahara Africa" as separate locations rather than as "Africa". There were also other sub regions listed rather than the usual 7 continents. This is because we wanted to group where people came from not only in terms of physical geography but cultural geography.

Of course even within a country there are different cultural and ethnic groups that people identify with, which change their perception of "home".

I guess it depends on why you are asking where people are, what are you hoping to do with that data, how is that going to affect what you write/do/talk about/whatever in the future.