Scottish Index of Multiple Deprivation: 2009 General Report

2. Introduction.

The purpose of this report is to provide an overview of the background to and the results and analysis of the 2009 update to the Scottish Index of Multiple Deprivation ( SIMD) and its constituent domains.

What is the SIMD?

2.1. The SIMD is the Scottish Government's official tool for identifying small area concentrations of multiple deprivation across Scotland. It is relevant for the targeting of policies and resources aimed at tackling areas where there are concentrations of multiple deprivation. The SIMD provides a relative ranking for each of 6,505 small areas, or datazones, across Scotland. It ranks these areas from one, being the most deprived, to 6,505, being the least deprived.

Multiple Deprivation

2.2. The terms deprivation and poverty are sometimes used interchangeably. In this context, deprivation is about the range of problems that arise due to lack of resources or opportunities, not just financial. The income domain picks up the lack of money issue that could be perceived as actual poverty. That said there are different definitions of both poverty and deprivation. The SIMD is one measure of deprivation and takes the approach that deprivation is multi-dimensional. As a result, it is necessary to use data relating to multiple aspects of life in order to gain the fullest picture possible of deprivation across Scotland. As a result of this, the SIMD consists of data from seven different subject areas or domains. The data from these domains are combined to produce an index that shows how deprived an area is in relation to all the other areas in Scotland.

Datazones

2.3. As previously mentioned, the SIMD is based on small areas called datazones. Datazones are a statistical geography that were developed in 2004. Datazones are population based with approximately 750 people living in each one. Because they are population based, datazones can vary hugely in size. In urban areas where people live very closely together, they can contain a few streets, while in more rural areas that are sparsely populated, they can cover miles. The datazone boundaries have remained stable since their creation in 2004, but the populations living within each datazone may have changed. For an analysis of the population drift please refer to the Scottish Neighbourhood Statistics User Forum (web link in Annex A).

Methodology

2.4. The methodology that is used to construct the SIMD 2009 is based on the approach developed by Oxford University for the Scottish Indices of Deprivation in 2003. This approach is widely accepted, with similar methodologies being used by England, Wales, and Northern Ireland. While similar methodologies are used across Great Britain and Northern Ireland, there are fundamental differences in the geographies and data used that mean that the indices are not comparable. A link to further information on this is available in Annex A. A general description is given here but full details of the methodology to create the 2009 SIMD are available in SIMD 2009 Technical Report.

Domains and Indicators

2.5. The domains used in the 2009 SIMD have remained the same as in the 2006 update (Income, Employment, Health, Education, Access to Services, Housing and Crime). Within each of these domains there are between two and eight indicators which were chosen for a number of reasons: (1) because of their ability to explain an aspect of deprivation, (2) because they are statistically robust, and (3) because of their availability at datazone level for the whole of Scotland.

Changes to the SIMD

2.6. The SIMD has National Statistics accreditation and as such, there is no political involvement in the choice of indicators or methodology used to construct the SIMD. Any changes that have been made have been done in conjunction with the SCOTSTAT Measuring Deprivation Advisory Group ( MDAG). The MDAG consists of users and analysts in Local Authority areas, police forces, experts in particular issues and analysts from within the Scottish Government. The MDAG provides the Scottish Government with advice on a number of aspects relating to measuring deprivation. The advice covers the needs of users, development priorities, methodological options, quality and range of outputs and guidance. All minutes and papers from meetings of the MDAG are published on the Scottish Government website.

2.7. There have been some changes to the data used between 2006 and 2009. In the Income Domain for example, Tax Credit data has been included. These changes have been kept to a minimum. However, care should be taken when interpreting results where these changes have occurred. There is a summary of any changes at the beginning of each domain chapter and full details of the indicators and any changes are available in the Technical Report.

2.8. In total, there are 38 indicators in SIMD 2009. This is one more than in 2006. As well as providing an overall rank for each datazone, the SIMD also provides a rank for each datazone for each domain. Therefore, it is possible to look at the Health Domain in isolation for example and to see how each datazone ranks. A list of the indicators used in the SIMD is included in Annex B with full details available in the SIMD 2009 Technical Report on the Scottish Government website, (see Annex A for links).

Constructing the index

2.9. The domains included in the SIMD 2009 are:

Income
Employment
Health
Education, Skills and Training
Access to Services
Housing
Crime

Each domain is made up of individual indicators which are listed in Annex B. The domains are calculated differently depending on the type of data used in each one.

2.10. The income, employment, housing and crime domains are created by summing counts of people and dividing by the appropriate population denominator taken from the Census or Small Area Population Estimates ( SAPEs). For the 2009 SIMD, the income and employment domains are constructed by counting the number of people claiming relevant benefits, and dividing by the total and working age population respectively. The populations are taken from the 2007 SAPE. Thus, the domain scores are a simple percentage.

2.11. The housing domain is the sum of people in households that are overcrowded or have no central heating, divided by the total household population from the 2001 Census. The crime domain is a count of selected recorded crimes, called SIMD crimes, divided by the 2007 SAPE total population, but is shown as a rate of SIMD crime per 10,000 population rather than a percentage of the population.

2.12. The health, education and access domains are constructed using factor analysis, which is a statistical technique that calculates weights for each indicator before they are added together to create the domain score. The indicators in these domains cannot simply be summed as they are not all counts and use different denominators. This means that the scores for these three domains are relative rather than absolute values and, as such, can not be used to measure absolute differences or absolute change.

2.13. The overall index is a weighted sum of the seven domain scores. Prior to weighting, the domains are standardised by ranking the scores. The ranks then undergo exponential transformation to avoid high ranks in one domain 'cancelling out' low ranks in another. The weights are applied to each of the domains, which are then combined to create the overall index. The weights are provided in Annex B. The resulting SIMD scores for each datazone are then ranked from one (most deprived) to 6,505 (least deprived).

2.14. A flow diagram summarising the SIMD 2009 methodology is available inside the back cover of this report.

Change over time

2.15. Due to the stable nature of datazones, it is possible to look at change over time from the 2004 SIMD to the 2006 update, through to the 2009 SIMD. As a result, this report contains not only the results and analysis of the 2009 SIMD, but also includes some analysis on the changes that have occurred since the SIMD was first published in 2004. It is important to bear in mind that not all change that has occurred will be considered real change, some of the change will be due to methodological change and some due to changes in the data. Also because of the relative nature of the SIMD some of the change seen will simply be to due to change in some datazones pushing others up or down the rankings. The report also contains guidance on how individuals can carry out their own analysis on change over time.

What is the SIMD for?

2.16. It is important to note that while the SIMD is the Scottish Government's official tool for measuring small area concentrations of multiple deprivation, it is not the only method of measuring deprivation. The SIMD has been developed for a specific purpose which is to identify small area concentrations of multiple deprivation. In attempting to use the SIMD, it is necessary to be clear about what exactly it is that is trying to be achieved. If the focus is on areas with high levels of multiple deprivation, then the SIMD can be used. If however, the focus is on all deprived people, then a different approach needs to be taken. In this case, it may be possible to use the underlying data from one of the domains rather than the overall index. However, as can be seen from Table 2.1 below of the Income Domain, not everyone living in a deprived area is deprived and not all deprived people live in deprived areas even when looking at individual domains.

Table 2.1: Levels of income deprivation in the most income deprived areas

	No. of Income Deprived People	Total Population	% Income Deprived
15% most income deprived	270,580	747,009	36%
Rest of Scotland	508,670	4,397,191	12%

2.17. Of the 724,300 people living in the 15% most income deprived areas in Scotland 36% of them are income deprived while in the rest of Scotland only 12% of the population are income deprived. This suggests that income deprivation is concentrated in certain areas but also shows that not all people living in deprived areas are deprived and not all deprived people live in deprived areas. The is further borne out by looking at the column titled 'No of Income Deprived People'. Here it can be seen that more income deprived people live outside the 15% most income deprived areas than live in them.

Uses of the SIMD

2.18. The SIMD can be used for :

• Identifying areas with high levels of deprivation.
• Identifying areas with specific issues e.g. health, that may not be considered deprived on the overall index.
• Comparing all the datazones in Scotland so the most/least deprived can be identified.
• Comparing Local Authorities or other larger geographical areas by looking at the proportion of the 15% most deprived datazones contained within each of the areas. Cut offs other than the 15% most deprived may also be appropriate.

Limitations of the SIMD

2.19. The SIMD cannot:

• Say how much more deprived one area is than another. The datazone ranked 50 is not twice as deprived as the one ranked 100 - in the same way as you cannot tell how much better the winner in a race performed than the person who came second. You need to look at the race times i.e. the underlying data to get an idea of the size of the difference between the two.
• Tell you if an area is affluent. The SIMD measures deprivation so at the lower end of the rankings (i.e. closer to 6505) all that can be said is that there is less deprivation. As mentioned earlier not all deprived people live in deprived areas and all people living in deprived areas are deprived. The SIMD only counts those classed as deprived.
• As the SIMD does not measure affluence it is also not possible to say that one area is more affluent than another or even relatively so.
• Be used to compare areas across the United Kingdom. While it is true that the indices for all the countries are based on the same methodology they all have a different base geography and use different indicators within the domains. The different indicators reflect things like different education systems and different availability of data.