How is migration derived? (cont.)
Place of last residence
On its own, a question about the place of last residence gives an estimate of lifetime migrants (all those who have lived somewhere other than where they currently reside) and an indication of migration flows by place of origin.
However, as with questions based on place of birth, there is no indication of when the migration occurred. This can be overcome by combining this question with a question about the duration of current residence. By asking about duration and place of last residence, migratory cohorts and the period of migration can be identified and studied.
Combined with a question on place of birth, a more complex picture of migration patterns can be built, giving an idea of intermediary migration and the extent of return migration. However the picture of migration will still be a simplified one, as these questions will only capture the previous migration.