City & Town Classification of Constituencies & Local Authorities

The House of Commons Library has developed a new classification of constituency and local authority areas according to the size of the settlements people live in. The classification is intended to assist in analysing data, and understanding differences, trends and inequalities across Great Britain. Each constituency and local authority is assigned to one of six categories, e.g. “Core City” or “Small Town”, which most closely matches its population distribution. This is intended to offer an alternative to rural/urban classifications in analysing variation.

Read our Insight article to see what this classification tells us about variation in house prices, population age and migration, and young people going to university.

(Classification summary; click for larger, or see downloads section for a a full-size pdf)

Why Cities and Towns?

Classifying areas according to whether they are urban or rural is a familiar concept. Recently, however, interest has grown in the varying fortunes of different-sized settlements – for example, whether cities have fared better than towns since the financial crisis. Rural/urban classifications don’t always provide a good way of dividing between towns and cities – for example, Cardiff (population 350,000) and North Walsham (population 12,500) are both classified as ‘urban city and town’. So the urban/rural classification wouldn’t be able to tell us about variation between settlements of different sizes, since it classifies both small towns and large cities with the same broad brush. 

Since there was no existing classification of constituencies & local authorities in terms of cities and towns, we set out to fill the gap. This classification provides an alternative way to analyse information for constituencies and local authorities. It is not intended as a replacement for other classifications: for many datasets, differences between urban and rural areas are the right thing to capture. But sometimes we can learn more by looking at variation between cities, towns, and villages. See our Insight article published today for some examples.

How does the classification work?

At its simplest, the classification categorises each constituency and local authority according to the type of settlement in which the largest proportion of its population lives. To achieve this, settlements are classified according to an adjusted version of the taxonomy recently developed by the Centre for Towns:

• 12 Core Cities: twelve major population and economic centres (e.g. London, Glasgow, Sheffield)
• 24 Other Cities: other settlements with a population of more than 175,000 (e.g. Leicester, Portsmouth, Aberdeen)
• 119 Large Towns: settlements with a population between 60,000 and 174,999 (e.g. Warrington, Hemel Hempstead, Farnborough)
• 270 Medium Towns: settlements with a population between 25,000 and 59,999 (e.g. Gravesend, Jarrow, Exmouth)
• 674 Small Towns: settlements with a population between 7,500 and 24,999 (e.g. Falmouth, New Romney, Holbeach)
• 6,116 Villages and small communities: settlements with a population of less than 7,500 (e.g. Chapel-en-le-Frith, Cottenham, Menai Bridge)

This classification isn’t intended to resolve long-standing disputes about which settlements deserve to be called ‘cities’, ‘towns’, or ‘villages’. In fact, it takes no account of the ceremonial definition of ‘city’, using the term only as a way to identify larger settlements. For instance, St Albans is identified as a ‘large town’ here because its population is 86,000 – even though it has city status. Luton, on the other hand, doesn’t have city status, but is classified here as an ‘Other City’ because its population is 225,000.

The precise division between ‘large’, ‘medium’ and ‘small’ towns is, to a large extent, subjective. The distinctions used here aim to provide a useful distribution of settlements across six categories for the purposes of analysis at constituency and local authority level.

Settlements classified in South Yorkshire

As noted above, we have made some changes to Centre for Towns’ settlement taxonomy in order to create a classification of constituencies and local authorities which best captures variation between different types of areas. Most notably, we have added a new ‘Other City’ category which captures the largest settlements that are not Core Cities. Because of this, we also altered the thresholds for the lower settlements categories in order to maintain a good distribution of settlements. In addition, we have used only a single category for villages and small communities, since distinctions between smaller settlements are less salient at the constituency and local authority level. Smaller differences and additions to Centre for Towns’ taxonomy are explained below.

How was the classification calculated?

The analysis matches almost 200,000 Census Output Areas to Built-up-areas and Built-up-area subdivisions* – geographies developed by the Office for National Statistics as part of the census. The set of output areas making up each Built-up-area and subdivision are the boundaries of the settlement for the purposes of this analysis. 2016 population estimates for output areas are then aggregated to estimate the population of each settlement.

The next step is to match each Output Area to a constituency and a local authority on a best-fit basis. Based on this, a population breakdown of each area is produced based on the settlements contained in the constituency.

An area’s City and Town Classification is the category that accounts for the largest percentage of the population. For example, 70% of Lancaster & Fleetwood constituency lives in a medium town, and 30% live in villages (or smaller settlements), so the constituency is classed as a ‘Medium Town’ constituency. 

Constituencies classified in South Yorkshire

Some constituencies and local authorities contain a range of different settlement types, meaning that it’s difficult to assign them to a main City and Town Classification. For instance, Redcar and Cleveland local authority is an even split between Medium Town, Other City, Village, and Small Town. To aid with cases like this, a column is provided showing the percentage of the population in each constituency and local authority that lives in the primary classification. For many analyses using the classification it may be appropriate to exclude areas where a relatively small percentage of the population lives in the primary classification, as these may not be representative of the category. The main classification spreadsheets highlight each case where a summary classification does not account for the majority of the population. Alternatively, it may be appropriate to divide an area’s data between multiple categories using the flat data sheets in the spreadsheet download.

Some towns form part of a larger conurbation with a core city. For example, the large town of Sutton Coldfield is ‘attached’ to Birmingham, the medium town of West Bridgford forms part of the Nottingham area, and the small town of Caterham is contiguous with London. Constituencies and local authorities in these areas are noted as being ‘in Conurbation’. This allows analysis of whether (for example) towns which are near to core cities have different experiences to towns which are not.

The ‘in conurbation’ flag is only used for towns near core cities – towns that are associated with non-core cities are not listed as conurbations. Also, the flag is used only in cases where towns are roughly contiguous with a core city – for example, while Morley is listed as being ‘in conurbation’ due to its proximity to Leeds, Halifax is not. Much like the decision about where to place the distinction between small/medium/large towns, the decision around whether to count areas as being ‘in conurbation’ is sometimes subjective.

Finally, for core cities only, a distinction is made between London and core cities outside of London. Since London’s population is greater than all other core cities combined, this allows analyses to correct for the fact that London is, on some indicators, unlike other core cities.

The boundaries of core cities include only their main administrative areas and not their broader built-up areas – e.g. the core city of Manchester includes only Manchester built up area subdivision and not Stockport, Salford, Trafford, etc. If you wish to look at trends for broader core cities, then you should include ‘in conurbation’ areas.

* Some of these details apply to England and Wales only: in Scotland, Datazones are used instead of Output Areas, and Localities instead of Built-up-Areas. Note that because built up areas are used as the basis for calculating populations, the populations used for each settlement won’t necessarily match other measures like parish boundaries.

How to use the classification

The spreadsheet in the downloads section (below) contains the information needed to undertake your own research using the city & town classification of constituencies and local authorities. It includes:

• 1. Constituencies: full data on the classification of each constituency and the distribution of its population between city/town categories
• 2. Local authorities: full data on the classification of each local authority and the distribution of its population between city/town categories
• 3. Constituencies: flat data showing the number and percentage of each constituency’s population in each city/town category
• 4. Local authorities: flat data showing the number and percentage of each local authority’s population in each city/town category
• 5. Output areas: source data showing the matching of each output area to a built-up area, and the city/town classification of each output area. This also includes a match to LSOA and MSOA geographies to allow for analysis at different levels.

The output area data is also available as a CSV download.

You can use spreadsheet software to match the geography codes provided with those used in published data, and then aggregate the data using city/town classifications. In Microsoft Excel, for instance, this may involve using the vlookup and pivot table functions.

Constituency and local authority data to use in analysis can be sourced from a range of publishers. We have aggregated a range of data on our website.

Data sources

ONS Geography, boundary data and lookups

ONS, Population estimates for small areas, 2016

National Records of Scotland, Mid-2016 population estimates

Scottish Government, Settlement and Locality datasets

Centre for Towns Classification