Time series migration in Britain: the context for 1991 census analysis.
"An administrative register, the National Health Service Central Register (NHSCR), is used by the Census Office (OPCS) to produce counts of NHS patients re-registering in different Family Health Service Authorities (FHSAs) in England and Wales. These movement data can be used to establish how unique or typical the migration occurring in the year prior to the Census was in relation to that for the whole decade. This paper examines national, regional and local examples of the information that can be extracted from a database system called TIMMIG that provides access to an NHSCR migration time series and a parallel series of mid-year population estimates. In advance of the publication of Special Migration Statistics, a preliminary comparison is made between the levels of in-migration to FHSA areas recorded in the NHSCR and in the 1991 Census."