I need to predict tourist arrivals by country of origin, by segment (hotels, camping etc...), by purpouse of travel (leiser or business)... so by breakdown within breakdowns.
My question is; I do not know if it is better to start from the top and go down level by level or to forecast each segment and add up for the next level. So in the first case, I would first forecast the total tourist arrivals, then the part for each country, then for each segment for each country and so on... in the second case, I would forecast a specific segment (i.e. tourist arrivals from Germany in hotels for leisure purpose) and add up progressively.
How to know which of these methods would be more accurate?
Thank you very much!