Keeping up with changes in local government geographies

In April 2019, five new English councils will come into existence, replacing fifteen current ones. More changes will follow in future years, as local government tries to be more effective within ever tighter budgets. Within new and existing local authority areas, the Electoral Commission continually redraws ward boundaries. Such changes make it hard to analyse data showing changes in places over time.

Forthcoming coming council of Bournemouth, Christchurch and Poole broken down by councils of 2018/9.

This short article shows how the Natural Neighbourhoods open data tool can help and how the Local Government Association’s LG Inform Plus reporting tool has applied it.

What Natural Neighbourhoods was designed for

As the name suggests, Natural Neighbourhoods was designed to let anyone define the areas around which communities naturally form. Ward boundaries may run down the middle of a high street or local authority boundaries (particularly in London) bisect or trisect town centres. Statistics that describe such areas can be hard to find and those which are published can be imprecise about that geography they describe.

I described this issue in an Open Data Institute guest blog in 2016. Since then, councils and individuals have added a diverse range of areas with persistent identifiers and precise machine-readable boundaries. These include: Business Improvement Districts, Children’s Centre Outreach Areas, Conservation areas, Family Hub areas, Fire station administration areas, Gang territories, Hospice boundaries, Housing estates, Pupil planning areas, Villages, and Water company boundaries.

Identifiers are consistent with the government’s standard for persistent resolvable identifiers. They lead to online descriptions and machine-readable data that can be used by anyone.

The LGA’s own LG Inform Plus is a major consumer of natural neighbourhood definitions. It uses the open relationships between areas defined and their component smaller geographies to generate metrics describing these user-defined areas.

Data tool showing population metrics with their derivation for a user-defined area

How Natural Neighbourhoods helps with official geographies

A side benefit of Natural Neighbourhoods is that it lets you see an overlay of one type of geography on another, such as the output areas making up a children’s service neighbourhood or the local authorities in and around a Clinical Commissioning Group area.

This can help when taking data for one domain, e.g. local authority social care metrics, and comparing it with data for another, e.g. health data for CCGs. Most CCGs manage areas covered wholly by one or more geographies, so precise CCG metrics can be calculated from local government data. Where there isn’t an exact fit, a “degree of fit” can be given.

So LG Inform Plus can repurpose the data it gathers for local government and apply it to such sectors as health, policing and parliamentary democracy.

Dealing with suggested and approved local authority changes

Changes to local government geographies over time present new challenges. Ward boundaries were redrawn for Birmingham, Manchester, Leeds and Newcastle and many other local authorities at the last local elections. These new wards don’t become official until the day of the elections, but councils need to prepare for them in advance and apply old data to these new areas, e.g. to understand trends over time.

Using the new boundary definitions from Natural Neighbourhoods, LG Inform Plus can show historic population trends for wards that only came into being in 2018.

Historic population metrics for new wards

Many councils share delivery of services, as shown by this LGA map, and combined authorities perform functions delegated from central government.

There are now also formal mergers of councils to cover bigger areas with just one organisational overhead. You can see which councils are starting and the ones they replace from the start and end dates in the Government Data Service Register of English Local Authorities.

Councils use the Proposed authority area type in Natural Neighbourhoods to test out new areas.

Looking forward and looking back at local authorities

Publishing new areas in advance of them becoming official and replacing old ones as they expire is not sufficient for a full analysis of available data. Two main problems remain.

Firstly, to combine and compare local authorities’ data, we need a full picture of the authorities (new and long-standing) that will exist. The same applies with wards. To solve this problem, we’ve added the Future local authority area type, giving all authorities approved to come into existence in future, plus all the others that remain unchanged. This allows LG Inform Plus to provide a comparison of all authorities that will exist in the year 2019/20. The same issue applies to wards, so we’ve added the Future ward area type, giving all pre-operative wards that have been approved, plus wards that will persist in future as far as we know.

Secondly, we need to accept that not all historic metrics can be reworked for new areas. Metric values may not be available for small areas that can be aggregated into new local authorities or wards. Even where they do exist for small areas, arithmetic aggregation must be statistically correct. Percentages and other rates cannot simply be added or averaged across the old authorities that come together to form new authorities. LG Inform Plus breaks down rates into their component numerators and denominators where possible, but sometimes these component parts are not published.

Hence we have introduced the area types of Local authority of 2018/9 and Ward of 2018/9. So, for example, a breakdown of Bournemouth, Christchurch and Poole by local authorities of 2018/19 will be possible long after those authorities have ceased to exist.

Some links for new local authorities

If you have an interest in the new authorities that start on 1 April 2019, these links may be of use to you:

These reports for authorities that start on 1 April 2019:

• Basic facts about Bournemouth, Christchurch and Poole Future local authority
• Basic facts about Dorset Future local authority
• Basic facts about East Suffolk Future local authority
• Basic facts about Somerset West and Taunton Future local authority
• Basic facts about West Suffolk Future local authority

These reports for authorities that start on 1 April 2019 broken down by wards that become operative on 2 May 2019:

• Basic facts about Bournemouth, Christchurch and Poole broken down by future ward
• Basic facts about Dorset broken down by future ward
• Basic facts about East Suffolk broken down by future ward
• Basic facts about Somerset West and Taunton broken down by future ward
• Basic facts about West Suffolk broken down by future ward