A definition of geodemographics (GDI) is the 'analysis of people by where they live'1. The term describes classification of small areas using a range of socio-economic data, such as deprivation, lifestyle and consumer behaviour.
Analysis using GDI provides a useful method for predicting household concerns or the risk of an event, for example being a victim of crime. GDI segments the population by household group and geographical unit, for example, electoral ward, or postcode. A range of data that comprises the following determines placement in a household group:
- demographic information, provided by the census and national surveys; and
- lifestyle information, provided by consumer, retail and commercial activity.
Geodemographics can help the interpretation of characteristics that people ascribe to a neighbourhood. Using a geodemographic based approach should help local agencies to understand why households living in one neighbourhood feel more similar to one another and less similar to people from other places. In aiming to reduce and prevent crime and anti-social behaviour, local agencies need a good understanding of how types of household are distributed in and between neighbourhoods.
Geodemographic information became commercially available in the UK in the late 1970s with CACI Ltd's release of ACORN (a classification of residential neighbourhoods). ACORN classified population data from the Office of National Statistics (ONS) census by electoral ward and postcode. Substantial developments since the 1980s mean GDI now incorporate a wide variety of census, lifestyle and consumer data.
The Home Office first used ACORN to classify responses to the British Crime Survey in the 1980s, in order to produce an analysis of fear of crime in different types of neighbourhood. ONS has also used ACORN and another GDI, Mosaic, to classify expenditure and food survey data by household group. More recently, local agencies have expressed an increasing interest in classifying data by household group. For example, educational attainment by school, social care need by area, crime and anti-social behaviour by victim and incident location, risk of fire by property type. A GDI based analysis during the desk research stage of neighbourhood profile compilation will provide information that is useful to every local agency.
The GDI analysis of the main household types within each electoral ward comprises the first section of each profile. The 11 main household groups described in the example profiles are defined by Mosaic UK.
- Group A. Career professionals living in sought after locations
- Group B. Young families living in newer homes
- Group C. Older families living in suburbs.
- Group D. Close knit, inner city and manufacturing town communities.
- Group E. Educated, young, single people living in areas of transient populations.
- Group F. People living in social housing with uncertain employment in deprived areas.
- Group G. Low-income families living in estate based social housing.
- Group H. Upwardly mobile families living in homes bought from social landlords.
- Group I. Older people living in social housing with high care needs.
- Group J. Independent older people with relatively active lifestyles.
- Group K. People living in rural areas far from urbanisation.
Data collection took place between April and September 2004. A longer analysis of the data for Section 1 and Section 2 of the example profiles is available in a report compiled for the Audit Commission by the Spatial Literacy in Teaching (Splint) Centre of Excellence in Teaching and Learning (CETL) (external link) at University College London (UCL).
1 Harris R, Sleight P, Webber R, Geodemographics, GIS and Neighbourhood Targeting, Wiley, 2005.