Ethnicities are assigned by person (designated variable 'ID' in driver+ethnicity.csv, for instance).
But a numerical (trip) ID ('num_id') is also given for each person -- what does this variable mean exactly? Why is it a 1-to-1 relationship, as if one driver only ever did on trip? Can we actually use the num_id to merge people to trips?
Where, if anywhere in the existing tables, is the connection between a person ID of a driver made with the person ID of a passenger? It exists in the raw data, but I'm not sure if anywhere else.
Ethnicities are assigned by person (designated variable 'ID' in driver+ethnicity.csv, for instance). But a numerical (trip) ID ('num_id') is also given for each person -- what does this variable mean exactly? Why is it a 1-to-1 relationship, as if one driver only ever did on trip? Can we actually use the num_id to merge people to trips?
Where, if anywhere in the existing tables, is the connection between a person ID of a driver made with the person ID of a passenger? It exists in the raw data, but I'm not sure if anywhere else.