The 1981 SWS derive from questions in the 1981 Census about place of usual residence and place of work. There are three sets of tables (SWS Sets A, B and C). Set A and Set B provide data on the employed and self-employed population by residential and workplace respectively. SWS Set C is the data set that involves interaction flow data..

SWS Set C are the journey-to-work flows within and between wards. For each origin-destination pair, 172 counts were produced in 5 separate tables, providing data on mode of transport to work, social class, socio-economic group, occupation, industrial division and age structure of males and females aged 16 and over in employment.

In an attempt to create a consistent comparison between 1981 and 1991, a recent Census Development Project has involved the re-estimation of 1981 SWS Set C 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 172 counts in 5 tables in the re-estimated SWS Set C data for which the geographical areas are identical to those used in 1991.

The SWS data are taken from a 10% sample and consequently have not been adjusted by OPCS for confidentiality. Users should also be aware that the commuting data on intra-ward flows includes those people who work at home as well as those who commute to work within the same ward.

Pro-rate distribution of workers with 'workplace unstated'

Workes who did not give a full workplace were coded as having 'workplace unstated'; in this version of the data those workers have been allocated workplaces in the same proportion as all other flows from each given residence.

References

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.