Contains migration flows within and between wards (in England and Wales) and postcode sectors (in Scotland). The entire data set is extremely large because there are 9,930 wards, 1,003 postal sectors and an additional 97 foreign origins, giving a matrix of 11,030 origins and 10,933 destinations, although the majority of the cells (interaction flows) at this spatial scale are zero.

Users can choose from 10 counts of migrants by age and sex (Table 1) and 2 counts of wholly moving households (Table 2).

All the 1991 SMS data have been derived from the 100% sample and include imputed households. However, OPCS suppressed migrant data in the SMS Set 2 in order to ensure confidentiality. Consequently, the imposition of suppression thresholds means that many smaller flows are not available. Phil Rees and Oliver Duke-Williams have estimated data for suppressed flows in Tables 3-10 and users wishing to use this data should select the SMSGAPS data set.

References

Flowerdew, R. and Green, A. (1993) Migration, transport and workplace statistics from the 1991 Census, in Dale, A. and Marsh, C. (eds) The 1991 Census User's Guide, HMSO, London: 269-94.

Rees, P.H. and Duke-Williams, O. (1995) The story of the British Special Migration Statistics, Scottish Geographical Magazine, 11: 13-26.

Rees, P.H. and Duke-Williams, O. (1997) Methods for estimating missing data on migrants in the 1991 British Census, International Journal of Population Geography, 3: 323-368.