This new table provides Census estimates that are consistent with the classifications used in 2001 (table KS015), e.g. if a person indicates their place of work is at their home address but said that they travel to work by driving a car or van, they will appear in the category “Work mainly at or from home”, as was the case in 2001. In contrast, the 2011 table QS701EW uses a person’s method of travel to work to classify them, even if they have ticked the “Work mainly at or from home” category.

(We have requested ONS add geography codes to this file as it currently only contains names).

- population centroid data for 2011 Census Output Areas, Lower Layer Super Output Areas and Middle Layer Super Ouptut Areas (the population weighted centroid is a single point that represent the median location of households). These may be extracted from the software using the header variables “Easting” and “Northing” which are stored on the updated System files.

- Quick Statistics tables: QS212EW (Passports Held (detailed)), QS214EW (National Identify (detailed)) and QS611EW (Approximate Social Grade).

This completes all the Key and Quick Statistics tables expected from the 2011 Census.

Next week (16/5) ONS will be releasing 42 Detailed Characteristic tables and will be the first detailed cross tabulations produced from the 2011 Census. This release represents Phase 1 of 3 in Release 3.0. 33 of these tables will be available for ward and Middle Layer Super Output Areas, 1 at Local Authority and 8 at regional level. The final table layouts can be found here (.xls).

Once the SASPAC team have loaded and quality assured this data, System files will be downloadable from the SASPAC website, along with a small software update. We’ll blog as soon as this data is available.

These datasets include 10% and 100% data for both Small Area Statistics and Local Based Statistics for all geographies in Great Britain and can be downloaded here (Be aware of file sizes when downloading).

Release 3.1 will commence on 16 May and will include tables covering the following topics at local authority level:

• Migration
• ethnicity
• identity
• country of birth
• language and religion
• health
• Welsh language skills

Release 3.2 and 3.3 are expected in June and July.

For more information on Release 3, see the ONS website. ONS are expecting to provide further layouts and updates to tables as information becomes available.

If you would like to attend, or have a colleague who would like to learn to use SASPAC, please contact Wil Tonkiss to book a place.

The introductory programme will provide users with all the tools they need to begin extracting and using census data. It is also an excellent opportunity for those who have used SASPAC before, but need a refresher, to brush up on their skills.

Full details of the course content can be found here: One-day Course.

To help support users we have recently added an FAQs page to our website – if you have any questions you’d like us to answer please send them through the helpdesk.

We’ve also added a number of software videos to support our training materials, which can be found here.

We will be updating these resources regularly and will notify you as and when new content goes live.

• AP1101EW Sex by five-year age group (non-UK born short-term residents)
• AP1102EW Sex by single year of age (non-UK born short-term residents)
•  AP1201EW Country of birth (non-UK born short-term residents)
• AP1202EW Passports held (detailed) (non-UK born short-term residents)
• AP1601EW Economic activity (non-UK born short-term residents)

A further four Quick Statistics tables were also released, detailing Passports held, Country of birth, National Identity, and Approximate social grade.

These tables can be downloaded from the ONS website and will be available in SASPAC shortly.

The Beyond 2011 programme is an ongoing programme within National Records of Scotland (NRS) to research suitable methods for producing population and socio-demographic information.

The questionnaire for user requirements can be completed on the NRS website or via www.surveymonkey.com. It can be responded to until Monday 10 June 2013.

More information on the Beyond 2011 programme and Stakeholder engagement sessions can be found on the NRS website or by contacting the Beyond2011 team.

The Issue

All 2011 Census ward estimates have been created using a method of best-fitting from the population weighted centroids of the underlying 2011 Census Output Area (OA). The population weighted centroid is a single point within the OA that represent the median location of households. The whole population of this OA is then assigned to the ward in which it falls. This means that where OA boundaries no longer match ward boundaries (i.e. they have changed since 2003 when the 2001 Census OAs were produced on an exact-fit to wards) the population/household estimates may not reflect all households physically located within the ward boundary. Conversely households outside the ward boundary may be included.

2011 best-fit of OAs to Wards: OA4 is allocated to WARD 2 because OA4′s population weighted centroid falls within the WARD 2 boundary (Source: ONS, An overview of best-fitting: Building 2011 Census Estimates from Output Areas)

Creating improved estimates

This is leading many organisations to look out how they can create improved best-fit estimates using alternative methods of redistributing the OA population more accurately. A number of methods can be used such as:

• using the proportion of each OA’s areal extent that falls within each ward (assumes the population is evenly distributed across the OA) or,
• using Census day address lists (e.g. Royal Mail Postcode Address File or the Local Land and Property Gazetteers maintained by local authorities) to distribute the population. Tees Valley Unlimited have very helpfully documented their approach here.  

Another approach will be possible when the 2011 Census Unit Postcode Headcount data (Postcode estimates tables are currently expected in May (p35 of the 2011 Census Prospectus (.pdf)) are published. These will provide details of the number of males, females and occupied households for each Census day postcode and will provide a very accurate method of redistributing the population to ward boundaries.

How SASPAC can help?

Once you have created the improved OA population distributions, SASPAC’s rezoning tool can then be used to easily recreate all the Census tables for these more accurate ward household or population distributions. For more information in how to rezone in SASPAC see Module 4 of our training manual.

Census estimates for other areas such as Parishes have also been best-fitted from whole OAs. This re-estimation method can be applied to any zones where best-fitted figures are insufficiently precise.

But remember…

Creating your own local ward estimates will produce alternative figures to those officially produced by ONS and should be documented and correctly labelled as such to avoid any confusion. Also, the best-fit methodology will be applied to create other ONS datasets, so care should be taken to use denominators created using the best-fit method.

Some useful resources:

ONS page on exact and best-fit estimates

ONS overview of the best-fitting methodology

Download median population weighted centroids for output areas, super output areas and workplace zones in shp and mid/mif format.

ONS National Postcode Directory

ONS 2001/2011 Census geography lookups products