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Output areas (2001) to output areas (2011) to local authority districts (2011) E+W Lookup

File Identifier: 675271ba-c9e0-44ae-b8f2-7ce9eb66836f
Metadata Language: English
Resource Type: Dataset
Responsible Party:
Organisation Name: Office for National Statistics
Role: Point Of Contact
Contact Info:
E-Mail Address:
Metadata Date: 2013-04-25
Metadata Standard Name: UK GEMINI
Metadata Standard Version: 2.1
Data Identification
Abstract: This is a best-fit lookup file between output areas as at December 2001 and output areas and local authority districts as at December 2011 in England and Wales. The original set of output areas created in 2003 from 2001 Census data, and constrained to 2003 administrative boundaries current at the time they were created, are referred to as 2001 output areas. Output areas (OA) are used across the United Kingdom as the base unit of 2001 Census output. In England and Wales OA are built from clusters of unit postcodes as at 2001 Census Day and fit within the boundaries of parishes and 2003 statistical wards. The minimum OA size is 40 resident households and 100 resident persons but the target size was rather larger at 125 households. These size thresholds meant that unusually small wards and parishes were merged into larger OA. The 175,434 OA in England (165,665) and Wales (9,769) were used as the building blocks for lower and middle layer super output areas (higher level statistical geographies). The 2001 output areas and super output areas were maintained using 2011 Census data and are referred to as 2011 output areas and super output areas. 2001 OA were modified where: - their 2011 population fell below 100 persons or 40 households: in which case it was merged with another OA. - their 2011 population rose above 625: in which case it was split into two or more OA. - they were aligned to local authority district boundaries that had changed between 2003 and 2011. - they were independently assessed as lacking social homogeneity when they were created for 2001. Local authority districts (LAD) is a generic term to describe the 'district' level of local government in England and Wales. It includes non-metropolitan districts, metropolitan districts, unitary authorities and London boroughs in England; and Welsh unitary authorities. The areas are made up of whole electoral wards/divisions. This product contains both the nine character codes as well as the old style ten character codes for the 2001 output areas. For further information, please see the Code History Database (CHD) link below. This product has been provided with a 'change indicator' field that defines the lookup between 2001 and 2011 output areas. This field indicates which output areas / super output areas have changed between 2001 and 2011. There are four designated categories to describe the changes, and these are as follows: - U - No Change from 2001 to 2011. This means that direct comparisons can be made between these 2001 and 2011 OA. - S - Split. This means that the 2001 OA has been split into two or more 2011 OA. There will be one record for each of the 2011 OA that the 2001 OA has been split into. This means direct comparisons can be made between estimates for the single 2001 OA and the estimates from the aggregated 2011 OA. - M - Merged. 2001 OA have been merged with another one or more 2001 OA to form a single 2011 OA. This means direct comparisons can be made between the aggregated 2001 OAs’ estimates and the single 2011 OA’s estimates. - X - The relationship between 2001 and 2011 OA is irregular and fragmented. This has occurred where 2001 OA have been redesigned because of local authority district boundary changes, or to improve their social homogeneity. These can’t be easily mapped to equivalent 2011 OA like the regular splits (S) and merges (M), and therefore like for like comparisons of estimates for 2001 OA and 2011 OA are not possible. Each 2001 OA with an ‘X’ code is best-fitted to a 2011 OA by plotting the 2001 OA’s centroid into a 2011 OA boundary. However, this does not imply an exclusive 1:1 relationship with a 2011 OA, as it will also have a relationship with fragments of other 2011 OA; the lookup is provided here so that all 2001 OA are included in the lookup. More information about the changes between 2001 and 2011 OA and SOA can be found in the document link below. In response to customer feedback, additional information to show the relationship between 2011 OA and local authority districts has been added to this product. Information on changes to local authority districts as part of the Local Government Reorganisation in 2009 has also been provided as a separate document. All 2011 output areas align exactly within the local authority district boundaries defined as at 31st December 2011. Please be aware that when exporting files out of the portal there is potential that certain Welsh characters could become corrupted. Please refer to attached spreadsheet for further information. In addition, if your downloaded file is imported into Access, the delimiter will need to be set to 'double quotes', so records are displayed correctly. Please be aware that if you download this lookup file in text or csv format and then import the file into ArcGIS 10.1, the ArcGIS software will make the assumption that the nine character geography codes contain information that relate to grid reference and attempt to create extra grid references fields based on these codes. If this happens please delete the extra grid reference information fields from your file as these grid references will not be valid or accurate.
Language: English
Title: Output areas (2001) to output areas (2011) to local authority districts (2011) E+W Lookup
Date: 2011-12-31
Date Type: Publication Date
Point Of Contact:
Individual Name: ONS Geography Customer Services
Organisation Name: Office for National Statistics
Role: Point Of Contact
Contact Info:
Voice: +44 (0)1329 444971
Delivery Point: Segensworth Road, Titchfield
City: Fareham
Administrative Area: Hampshire
Postal Code: PO15 5RR
Country: United Kingdom
E-Mail Address:
Online Resource:
Topic Category: Cultural, Society and Demography
Keyword Collection:
Keyword: Statistical units
Keyword: Geographical names
Associated Thesaurus: GEMET - INSPIRE themes, version 1.0
Keyword: Output area
Keyword: OA
Keyword: local authority district
Keyword: LAD
Keyword: England and Wales
Keyword: EW
Keyword: E+W
Associated Thesaurus: ONS
Spatial Extent:
West Bounding Longitude: -8.17167
East Bounding Longitude: 1.74944
North Bounding Latitude: 60.8433
South Bounding Latitude: 49.9553
Legal Constraints:
Access Constraints: Other Restrictions
Other Constraints: Other Restrictions
Distribution Format:
Format Name: ArcGIS
Format Version: 10.1
Transfer Options:
Function: Download
Transfer Options:
Function: Information
Transfer Options:
Function: Information
Transfer Options:
Function: Information
Transfer Options:
Function: Information
Scope: Dataset
Conformance Result:
Validation Performed: true
Title: COMMISSION REGULATION (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
Date: 2010-12-08
Date Type: Publication Date
Lineage: 97.4% of the 2001 OA are unchanged in the 2011 set of OA. Changes to the 2.6% of the 2001 OA that did change were where they were either split or merged as a result of significant population change, to align with local authority district boundaries changed since 2003, or where they were changed to improve their social homogeneity. The local authority district names were taken from the Statutory Instrument (SI) and the codes were created by ONS.
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