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Statistical bulletin: Parliamentary Constituencies Population Estimates, Mid-2011 (Census Based)

Released: 30 May 2013 Download PDF

Annual Mid-year Population Estimates for parliamentary constituencies, 2011

  • The 573 Westminster Parliamentary Constituencies in England and Wales have a mean population of 98,000 in mid-2011.
  • On average Westminster Parliamentary Constituencies in Wales have smaller populations than those in England, with a mean population size of 76,600 compared to 99,600 in England.
  • Predominantly urban ‘borough’ constituencies have a mean population size of 102,400; while the more rural ‘county’ constituencies have a mean population size of 94,400.
  • The population age distribution varies widely across the country with the parliamentary constituencies with the youngest median ages being located in central areas of large cities.
  • Mid-2011 parliamentary constituency population estimates are based on the results of the 2011 Census.
  • Parliamentary constituency population estimates are of particular interest to parliamentary organisations, researchers and MPs.

Summary

This bulletin presents the 2011 mid-year population estimates for the Westminster Parliamentary Constituencies in England and Wales. These estimates are based on the results of the 2011 Census and are available for the constituency boundaries that were introduced for the May 2010 General Election. Parliamentary constituency estimates are part of a wider suite of small area population estimates.

In general, small area population estimates are used by both central government departments and local authorities for a range of purposes including planning and monitoring of services; as denominators for the calculation of various rates and indicators and as a base for population projections and forecasts. Additionally, parliamentary constituency population estimates are of particular interest to parliamentary organisations, researchers and MPs.

Introduction

Mid-year population estimates for 2011 for England and Wales, regions within England and local authorities within England and Wales, based on the results of the 2011 Census, were published on 25 September 2012. The estimates refer to the usually resident population as at 30 June of the reference year and are published annually. In mid-2011 the population of England and Wales was 56,170,900, an increase of 7.3% over the ten years since mid-2001.

Small Area Population Estimates

Mid-year population estimates for parliamentary constituencies form part of the suite of small area population estimates for England and Wales, which are produced annually, usually approximately three to four months after the publication of the national, regional and local authority level estimates. However, these estimates for mid-2011 have been published approximately eight months after the national estimates due to the additional time required to incorporate the results of the 2011 Census.

There are two main types of small area population estimates:

  • Super Output Area (SOA) estimates – National Statistics including estimates for middle and lower layer SOAs.

          Mid-2011 estimates for SOAs were published on 11 April 2013.

  •  Estimates for other geographies – Experimental Statistics including estimates for National Parks, parliamentary constituencies and wards.

          Mid-2011 estimates for wards have been published alongside this release.

          Mid-2011 estimates for National Parks are provisionally due to be published in July/August 2013.

The mid-2011 parliamentary constituency population estimates, referred to in this bulletin, are based on the 2011 Census, updated to account for population change during the period between Census day (27 March 2011) and the mid-year point (30 June 2011). They are fully consistent with population estimates for SOAs and higher levels of geography including local authorities and the national total for England and Wales.

Methodology

Small area population estimates for other geographies, including the parliamentary constituency estimates, are produced using Census Output Areas (OAs) as building blocks. Therefore the population of each small area is the sum of the population of the OAs which provide the ‘best-fit’ to the actual geographic boundaries of the area. This approach is in accordance with the Geography Policy for National Statistics (55.9 Kb Pdf) published in July 2010.

Mid-2011 population estimates for OAs have been produced from the SOA estimates published in April 2013 using an apportionment method based on 2011 Census data. Full descriptions of the methods used to calculate mid-2011 small area population estimates, for both SOAs and other geographies, are available from the ONS website.

For further information on the quality and use of these statistics, please see the Quality and Methodology Information (129.3 Kb Pdf) for Small Area Population Estimates.

Mid-2011 Parliamentary Constituency Population Estimates

Westminster Parliamentary Constituencies are the areas used to elect Members of Parliament (MPs) to the House of Commons, the primary legislative chamber of the UK. The current boundaries were introduced for the May 2010 General Election and include 533 constituencies in England and 40 in Wales.

At mid-2011, the mean population of parliamentary constituencies in England and Wales was 98,000 with population sizes ranging from 56,500 in Aberconwy to 159,500 in West Ham. On average, English constituencies have larger populations than Welsh constituencies with mean populations of 99,600 and 76,600 respectively.

Parliamentary constituencies are classified into two broad types of area: borough constituencies, which are defined as predominantly urban areas; and county constituencies, which are partly or mostly rural areas. The designation of a constituency as either borough or county is made by the relevant Boundary Commission. Overall, 55% of constituencies are classified as county constituencies and 45% are classified as borough constituencies.

Figure 1: Distribution of borough and county parliamentary constituencies in England and Wales by total population estimate, mid-2011

Figure 1: Distribution of borough and county parliamentary constituencies in England and Wales by total population estimate, mid-2011
Source: Office for National Statistics

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Figure 1 above shows the different distributions of borough and county parliamentary constituencies by total population size. Most of the constituencies with populations over 110,000 are the predominantly urban borough areas whilst the majority of constituencies with a population size of less than 100,000 are the more rural county areas. The mean population size of borough constituencies is 102,400 compared to only 94,400 in county areas.

The majority of the 11 constituencies with population greater than 130,000 are in London (63.6%) whilst the majority of the 35 constituencies with a population size of less than 80,000 are in Wales (71.4%).


 

Age Distribution

The median age of the population of England and Wales in mid-2011 was 39.5, an increase of 1.6 years since mid-2001.

The median age of parliamentary constituencies within England and Wales varies widely between different areas. In mid-2011 the constituency with the youngest median age (26.3) was Sheffield Central. All of the top ten constituencies with the youngest median ages, shown in table 1 below, are in large cities which have large student populations. The top ten includes only one London constituency, Bethnal Green and Bow, and only one Welsh constituency, Cardiff Central. The next Welsh constituency in the ranking, Cardiff South and Penarth, is 99th with a median age of 35.1.

Table 1: Parliamentary constituencies in England and Wales with youngest median age, mid-2011

Rank Parliamentary Constituency Median Age
1 Sheffield Central 26.3
2 Birmingham, Ladywood 27.2
3 Cardiff Central 27.4
4 Manchester Central 27.6
5 Leeds Central 28.1
6 Manchester, Gorton 28.3
7 Nottingham South 28.3
8 Newcastle upon Tyne East 28.6
9 Birmingham, Hodge Hill 28.8
10 Bethnal Green and Bow 28.9

Table source: Office for National Statistics

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The highest median age in mid-2011 was 52.4 in Christchurch. Nine of the top ten parliamentary constituencies with the highest median ages, as shown in table 2 below, are located in coastal areas of southern and eastern England which are known for their large populations of people of retirement age. The exception is Westmorland and Lonsdale, which is in North West England and includes parts of both the Lake District and Yorkshire Dales National Parks as well as the towns of Kendal, Kirkby Lonsdale and Windermere.

Table 2: Parliamentary constituencies in England and Wales with oldest median age, mid-2011

Rank Parliamentary Constituency Median Age
1 Christchurch 52.4
2 North Norfolk 52.1
3 New Forest West 50.7
4 Clacton 50.7
5 Totnes 50.0
6 Louth and Horncastle 49.7
7 West Dorset 49.3
8 Bexhill and Battle 49.0
9 Suffolk Coastal 48.5
10 Westmorland and Lonsdale 48.3

Table source: Office for National Statistics

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The parliamentary constituency in Wales with the oldest median age at mid-2011 is Dwyfor Meirionnydd, ranked 13th with a median age of 48.0. This constituency includes a large part of the Snowdonia National Park.

Voting Age

In England and Wales in mid-2011 there were 44,197,700 persons aged 18 and over, making up 78.7% of the total usual resident population. This was an increase of 1.2 percentage points over the 10 year period since mid-2001. In mid-2011, at parliamentary constituency level, the percentage of the population aged 18 and over varied from 66.3% in Birmingham, Hodge Hill to 87.4% in Cities of London and Westminster.

The population of voting age in a parliamentary constituency is not the same as the population who are entitled to vote as it includes people who are not eligible to vote. For example, European Union citizens (excluding British citizens; and Irish, Cypriot and Maltese citizens who are qualifying Commonwealth citizens) are not entitled to vote in Westminster parliamentary elections but are included in the population estimates if they are resident in the UK for 12 months or more.

Electoral statistics, providing counts of the number of persons registered to vote in each parliamentary constituency, are available on the ONS website.

Comparison with 2011 Census estimates

The mid-2011 census-based population estimates are not directly comparable with the 2011 Census results at parliamentary constituency level for the following reasons:

  • The reference point of the two datasets is different. The mid-year estimates refer to 30 June 2011 and the census estimates to 27 March 2011. The mid-year estimates account for any population change that has occurred between these dates.

  • In order to ensure that the members of the armed forces were enumerated consistently, the 2011 Census was designed so that members of the armed forces were enumerated at their ‘permanent or family home’ (this is considered to be their usual residence for census purposes). The mid-year estimates definition of usual residence for armed forces is different as it may be either their ‘permanent or family home’ or the armed forces base, depending on individual circumstances. For the purposes of calculating mid-year population estimates, an adjustment has been applied to the 2011 Census data at Output Area (OA) level to reallocate members of the home armed forces from their ‘permanent or family home’ to their place of residence at the armed forces base, where these are different. The majority of this adjustment will also be present in the parliamentary constituency estimates, as they are created by aggregating OA estimates.

The 2011 Census estimates also provide data for a wider range of population characteristics such as economic activity, ethnicity or religion. Data for parliamentary constituencies can be obtained from either:

Small Area Population Estimates for other UK Countries

Small Area Population estimates for Scotland and Northern Ireland are produced by National Records of Scotland (NRS) and the Northern Ireland Statistics and Research Agency (NISRA) respectively. A paper, Small Area Population Estimates across the UK which provides a broad description of the different methodologies used to produce the wider set of small area population estimates in each constituent country of the UK, is available on the NISRA website.

Population estimates for Westminster Parliamentary Constituencies in Scotland are available from the NRS website. The latest estimates for mid-2011 based on 2001 Census data were published in August 2012.

Population estimates for Westminster Parliamentary Constituencies in Northern Ireland are available from the NISRA website. The latest estimates are for mid-2010 and are also based on 2001 Census data.

Publications in 2013

This list below shows the other small area population estimates products which are planned for publication in 2013. The majority of the dates given below are provisional. Final confirmed dates will be available on the UK National Statistics Publication Hub release calendar at least four weeks before publication.

  • Population estimates for wards, mid-2011: published alongside this release.

  • Population estimates for Clinical Commissioning Groups, mid-2011: July 2013

  • Population estimates for National Parks, mid-2011: July/August 2013

  • Super Output Area (SOA) population estimates, mid-2002 to mid-2010 revised: August/September 2013.

  • Super Output Area (SOA) population estimates, mid-2012: September/October 2013.

  • Small area population estimates for wards, parliamentary constituencies and National Parks, mid-2002 to mid-2010 revised: November/December 2013.

  • Small area population estimates for wards, parliamentary constituencies and National Parks, mid-2012: November/December 2013.

Further research work on small area population is planned to be completed following the publication of the products listed above. This is likely to include:

  • Detailed assessment of the difference between 2011 Census SOA population estimates and the estimates for mid-2011 based on the 2001 Census.

  • Review of the methods used to produce small area population estimates in the light of the results of the 2011 Census.

 

Background notes

  1. An Overview of Population Statistics is available on the ONS website.

  2. Published tables include population estimates for parliamentary constituencies by five year age/sex groups.

  3. A report describing the methodology used to create the parliamentary constituency population estimates is available on the ONS website.

  4. This is the first release of mid-2011 population estimates for parliamentary constituencies in England and Wales. No revisions of this dataset have been made.

  5. Mid-2011 population estimates for England and Wales and for local authorities are also available on the ONS website.

  6. Mid-2011 population estimates for Output Areas are provided as supporting information to this release.

  7. Next publication:
    November/December 2013
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Statistical contacts

Name Phone Department Email
Pete Large +44 (0)1329 444661 Population Estimates Unit sape@ons.gsi.gov.uk
Get all the tables for this publication in the data section of this publication .
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