Abstract
Describes migrations, which can (and must be) linked to Individual and Household Residency Start and End Events (IRStartEvent and IREndEvent, HRStartEvent and HREndEvent) Hence this dataset is only useful in conjunction with the Individual and Household Residency datasets It cannot be used 'standalone' An internal migration, i.e. from one Bounded Structure to another within the DSA, will identify the two BSIDs in OriginBSIntid and DestinationBSIntId. The individuals (or Households) involved should have a Residency episode at OriginBSIntId which has an EndEvent which is the migration MIntId. They should also have subsequent Residency episode at DestinationBSIntId which has a StartEvent which is again the Migration MIntId. Note that this implies that for all internal migrations the EndEvent of the origin Residency episode and the StartEvent of the subsequent, destination Residency episode will be the same event. For InMigrations i.e. moves into the DSA from outside, the OriginBSID should be blank, but the Destination should not be. The individuals or Households involved should have a Residency episode at the destination BSIntId which has a StartEvent matching the MIntId, and which will be of Type EII or EHI. For Outmigrations i.e. moves away from the DSA, the destination BSIntId will be blank, but the origin will not. The individuals or households moving out will have a Residency episode at the Origin BSIntid which has an EndEvent matching the MIntId and which will be of Type EIO or EHO. Note there is redundancy in the Migrations vs Residencies datasets insofar as the BSIntIds involved are always identified in both. It would be good to investigate the extent to which they are in fact consistent. It would also be useful to investigate how many 'orphan' Migrations there are (i.e. ones that are no referred to in any Residency. In a perfectly clean dataset there should be no inconsistent BSIntIds at all and no 'orphans'.
