Employment and commuting

Appendix D: Technical Note: Adjustments to the Data

The issue

  1. In 1991 there were a substantial number of Calderdale residents in employment for whom no workplace could be identified. Equally, there was a large number of people working in Calderdale for whom no origin was available.
  2. The reasons for this are likely to include:
    • section not completed on Census form
    • indecipherable addresses on Census form
    • wrong postcodes
    • confusion about people working in different locations
    • confusion about working from no fixed location.
  3. In the 2001 Census, there are no missing records; routines have been undertaken to ensure all people in work have a work location.
  4. Therefore, to derive accurate figures on the changes in commuting, and changes in the origins and destinations, it is necessary to make an estimate of the 1991 figures that adjusts for the missing records.

Assumptions

The adjusted figures have been derived on the basis of the following assumptions:

  1. the unstated and unidentified records will apply in equal proportion to people working from home, working outside their home District, or working within their home District
  2. the rate of missing records affects all destinations in proportion to the published Census output

Calculations

  1. 1991 Special Workplace Statistics (SWS) showed that – excluding Unstated / Unidentified records - 23.76% of Calderdale residents in employment worked outside the District.
    Applying this rate to the total number of Calderdale residents in employment (85330) gives the following figure:

    residents working outside the District in 1991: 20270
    since this is an estimated figure, this is rounded to 20300

    This represents a grossing up of outflows of 8.99%
  2. The SWS also showed that – excluding Unstated / Unidentified records – 20.14% of the Calderdale workforce came from outside the District.
    Applying this rate to the total number of people employed within Calderdale (81,750) gives the following figure:

    employees working within Calderdale who live outside the District: 16459
    since this is an estimated figure, this is rounded to 16500

    This represents a grossing up of inflows of 9.71%
  3. In line with the assumption numbered 2 above, all Destination figures have consequently been grossed up by 8.99%
  4. In line with the assumption numbered 1 above, all Origin figures have been grossed up by 9.71%

Last Updated: 05/08/2015