Flow Data Information System

1981 Census: Special Migration Statistics (using 1981 geography at county/region level)

The 1981 SMS refer to counts of individuals who were in existence 12 months before the Census and who were resident at a different usual residence on 5 April 1981 to that a year previously.

This version of the data set uses original 1981 geography, but is limited to county and region level. The 1981 SMS data are available at a more detailed (ward) level for 1991 based boundaries in other data sets. The structure of the original data makes it hard to work them at more detailed spatial scales; however users who may be interested in the original 1981 data should contact CIDS and ask for more information


1981 SMS Set 2 are separate counts of males and females migrating within and between each pair of wards defined in 1981. They have not been subject to data adjustment or thresholding. In an attempt to create a consistent comparison between 1981 and 1991, a recent Census Development Project has involved the re-estimation of 1981 SMS Set 2 data for wards whose boundaries were used in the 1991 Census. The estimation methodology is available in a paper published in Computers, Environment and Urban Systems (Feng and Boyle, 2001)

Users can choose between 2 counts (males and females) in the re-estimated SMS Set 2 data for which the geographical areas are identical to those used in 1991.


Ballard, B. and Norris, P. (1983) User needs - an overview, Chapter 3 in Rhind, D. (ed) A Census User's Handbook, Methuen, London: 89-113.

Cole, K. and Squires, S. (1987) The Special Migration Statistics from the 1981 Census: the data and their implications, Paper presented at the LAMSAC Workshop, County Hall, London.

Feng, Z. and Boyle, P. (2001) Integrating the 1981 and 1991 census interaction data, Computers, Environment and Urban Systems, forthcoming.

Citation information

The following statements should be attached to all output produced using this data set

Data from this set should be cited in a bibliography as:

Office for National Statistics, 1981 Census: Special Migration Statistics (using 1981 geography at county/region level) [computer file], UK Data Service

Further information

This data type is derived from:

The following pre-defined totals are available from this data set:

There are 1 tables defined for this data set:

The data are available for the following geographies:

Geographies of origin areasGeographies of destination areas
Supported directly
[i]1981 SMS foreign origins
[i]1981 SMS unstated origin
[i]1981 census county/region
[i]1981 census county/region
Supported via aggregation

Output for geographies that are only supported via aggregation will take longer than for those supported directly

Table frameworks

Table 1: Migrants usually resident/formerly resident in county/region by sex
Male Female
Count 1 2