Deprivation index


A deprivation index or poverty index is a data set used to measure relative deprivation of small areas. Such indices are used in spatial epidemiology to identify socio-economic confounding.

History

In 1983, Brian Jarman published the Jarman Index, also known as the Underprivileged Area Score, to identify underprivileged areas. Since then, many other indices have been developed.

Australia

Canada

publishes the Canadian Index of Multiple Deprivation.

China

China's county-level area deprivation index

Europe

European Deprivation Index

The European Deprivation Index was published by Launoy et al in 2018 with a goal of addressing social inequalities in health.

Laeken indicators

The Laeken indicators is a set of common European statistical indicators on poverty and social exclusion, established at the European Council of December 2001 in the Brussels quarter of Laeken, Belgium. They were developed as part of the Lisbon Strategy, of the previous year, which envisioned the coordination of European social policies at country level based on a set of common goals.
Laeken indicators include the following.
  • At-risk-of-poverty rate
  • At-risk-of-poverty threshold
  • S80/S20 income quintile share ratio
  • Persistent at-risk-of-poverty rate
  • Persistent at-risk-of-poverty rate
  • Relative median at-risk-of-poverty gap
  • Regional cohesion
  • Long-term unemployment rate
  • Persons living in jobless households
  • Early school leavers not in education or training
  • Life expectancy at birth
  • Self defined health status
  • Dispersion around the at-risk-of-poverty threshold
  • At-risk-of-poverty rate anchored at one moment in time
  • At-risk-of-poverty rate before cash social transfers
  • Gini coefficient
  • In-work at risk of poverty rate
  • Long term unemployment share
  • Very long term unemployment rate
Most of these indicators are discriminated by various criteria.

France

Germany

The German Index of Multiple Deprivation

Italy

The Italian deprivation index

Switzerland

The Swiss neighbourhood index of SEP.

United Kingdom

Indices of Multiple Deprivation

Indices of multiple deprivation are datasets used within the UK to classify the relative deprivation of small areas. Multiple components of deprivation are weighted with different strengths and compiled into a single score of deprivation. Small areas are then ranked by deprivation score. As such, deprivation scores must be treated as an ordinal variable.
They are created by the British Department for Communities and Local Government. The principle behind the index is to target government action in the areas which need it most.
The calculation and publication of the indices is devolved and indices of multiple deprivation for Wales, Scotland, England, and Northern Ireland are calculated separately. While the components of deprivation that make up the overall deprivation score are similar in all four nations of the UK the weights assigned to each component, the size of the geographies for which deprivation scores are calculated, and the years of calculation are different. As a result levels of deprivation cannot be easily compared between nations.
The geography at which IMDs are produced varies across the nations of the UK and has varied over time. Currently the smallest geography for which IMDs are published is LSOA level in both England and Wales, data zone level for Scotland, and Super Output Area for Northern Ireland. Early versions of the English IMDs were published at electoral ward and English local authority level.
The use of IMDs in social analysis aims to balance the desire for a single number describing the concept of deprivation in a place and the recognition that deprivation has many interacting components. IMDs may be an improvement over simpler measures of deprivation such as low average household disposable income because they capture variables such as the advantage of access to a good school and the disadvantage of exposure to high levels of air pollution. A potential disadvantage is that the choice of components and the weighting of those components in the construction of the overall multiple deprivation score is unavoidably subjective.
Using an IMD to assess outcomes with a deprivation gradient may introduce circularity or endogeneity bias if the outcome overlaps with an IMD indicator. For instance, standardised mortality rates, which show a deprivation gradient, contribute to the health domain of the Scottish IMD. While evidence suggests minimal impact on inequalities research, researchers often use only the income domain to avoid this bias.

Cases for indexes of multiple deprivation at larger and smaller geographies

IMDs are calculated separately for England, Wales, Scotland, and Northern Ireland and are not comparable across them. While the geographies, the input measures, and the weights assigned to each input measure are different in all four countries, they are similar enough to calculate a combined UK IMD with only small sacrifices in data quality. Decisions within the UK that are taken nationally would be usefully informed by a UK index of multiple deprivation and this work has been proven possible and performed. The most recent whole-UK index of multiple deprivation was compiled by MySociety in 2021.
There are also examples of IMDs being created for smaller geographies within nations. This is particularly important in places with very high deprivation in almost all areas. For example, using English IMDs in Manchester is not useful for targeting local interventions since over half of the city is classed as being in England's most deprived decile. By using raw deprivation scores for small areas within the area of interest before they are ranked at the national level, a local IMD can be calculated showing relative deprivation within a place instead of its relative deprivation within England.

Applicability of IMDs to the analysis of very diverse areas

IMDs are the property of a small area and represent the average characteristics of the people living in that area. They are not the property of any single person living within the area. Research has demonstrated IMDs have low sensitivity and specificity for detecting income- and employment-deprived individuals. Failure by researchers to consider this can lead to misleading features in analysis based on IMDs. This is a particularly large risk in areas which are very diverse due to social housing and mixed community policies such as central London. In these settings, a mixed community with a mix of very low income families in poor health and very high income families in good health can return a middling IMD score that represents neither group well and fails to provide useful insight to users of analysis based on IMD data. Other groups not well represented by IMDs are mobile communities and people experiencing homelessness, some of the most deprived members of society.

National indices

Responsibility for the production of publication of IMDs varies by the nation that they cover. Northern Ireland Statistics and Research Agency publishes IMDs for Northern Ireland. StatsWales publishes IMDs for Wales. The Scottish Government publishes IMDs for Scotland. The UK Department for Levelling Up, Housing and Communities publishes IMDs for England.
Early version of English IMDs were produced by the Social Disadvantage Research Group at the University of Oxford.
The most recent IMDs for the four nations of the UK are,
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    Scottish Index of Multiple Deprivation
The Scottish index of multiple deprivation is used by local authorities, the Scottish government, the NHS and other government bodies in Scotland to support policy and decision making. It won the Royal Statistical Society's Excellence in Official Statistics Awards in 2017.
The SIMD 2020 is composed of 43 indicators grouped into seven domains of varying weight: income, employment, health, education, skills and training, housing, geographic access and crime. These seven domains are calculated and weighted for 6,976 small areas, called 'data zones', with roughly equal population. With the population total at 5.3 million that comes to an average population of 760 people per data zone.

1983: Jarman Index, Underprivileged Area Score

In 1983, Brian Jarman published the Underprivileged Area Score, which became known as the Jarman Index.
This measured socio-economic variation across small geographical areas. The score is an outcome of the need identified in the Acheson Committee Report to create an index to identify 'underprivileged areas' where there were high numbers of patients and hence pressure on general practitioner services.
Its creation involved the random distribution of a questionnaire among general practitioners throughout the UK. This was then used to obtain statistical weights for a calculation of a composite index of underprivileged areas based on GPs' perceptions of workload and patient need.

1988: Townsend Deprivation Index

The Townsend index is a measure of material deprivation within a population. It was first described by sociologist Peter Townsend in 1988.
The measure incorporates four variables:
  • Unemployment ;
  • Non-car ownership ;
  • Non-home ownership ; and
  • Household overcrowding.
These variables can be measured for the population of a given area and combined to give a "Townsend score" for that area.
A greater Townsend index score implies a greater degree of deprivation. Areas may be "ranked" according to their Townsend score as a means of expressing relative deprivation.
A Townsend score can be calculated for any area where information is available for the four index variables. Commonly, census data are used and scores are calculated at the level of census output areas. Scores for these areas may be linked or mapped to other geographical areas, such as postcodes, to make the scores more applicable in practice. The Townsend index has been the favoured deprivation measure among UK health authorities.
Researchers at the University of Bristol's eponymous "Townsend Centre for International Poverty Research" continue to work on "meaningful measures of poverty".