Problems of inconsistency in geographical areas

• National: no migration data for Northern Ireland in 1990-91

• Regional: local government re- organisation during the 1990s

• Local: OAs introduced to England, Wales and Northern Ireland in 2001 (Scotland 1991)

Notes:

Problems of inconsistency in geographical area definition stem from

no migration data being available for Northern Ireland in 1990-91;

local government re-organisation during the 1990s