Data sources and suitability - introduction
This page lists and describes some of the main official data sources available to statistical users interested in income and poverty in Scotland. The reliability, accuracy and suitability of each source is discussed. The sources are organised into three groups according to the smallest geographical area for which data are available: 'National and International', 'Sub Scotland (including local authority level data)' and 'datazone level'. Future developments in official income and poverty statistics are also discussed.
Data sources and suitability - contents
National and International data
Sub Scotland level data
Datazone level data
DWP Family Resources Survey ( FRS) and Households Below Average Income dataset ( HBAI)
The Family Resources Survey ( FRS) is the official source of UK and Scottish Government information about income and poverty. It is a face-to-face survey interviewing approximately 4,500 households in Scotland and 26 ,000 households across the UK as a whole. The FRS is run by DWP and aims to collect detailed information about respondents' incomes from employment and other sources. The Households Below Average Income dataset ( HBAI) is derived from the FRS and is the source of UK and Scottish Government official income and poverty estimates.
Household responses are weighted and grossed up to be representative of all private households in Scotland. Incomes are equivalised (to take into account household composition) using the OECD equivalisation scale. Once equivalised, weighted and grossed, the total income of every individual is summed to arrive at the total income figure.
The FRS is one of the best sources for understanding changes to the distribution of income over time and the 'risk' of poverty for various groups insociety. At Scottish and UK level HBAI income and poverty figures are considered to be among the most robust available from any source. These estimates however, are not available at Local Authority level or smaller geographies.
Annual Survey of Hours and Earnings
The Annual Survey of Survey of Hours and Earnings is a survey of employers which provides information about levels, distribution and make-up of earnings and working patterns across the UK. The survey is run by the Office for National Statistics and provides local authority level estimates of earnings which can be broken down by industry, occupation and full time/part timework.
The survey only concerns earnings from work and so these figures cannot be used to produce comparable poverty estimates to those from the Family Resources Survey which includes income from other sources. Self employed, and unemployed people are also excluded from the earnings figures. Nonetheless, the local authority level earnings figures produced from ASHE may be useful to researchers interested in understanding the broader picture of income at a local authority level.
Scottish Household Survey ( SHS)
The Scottish Household Survey ( SHS) is designed to provide accurate, up-to-date information about the characteristics, attitudes and behaviour of Scottish households and individuals on a range of issues. This includes information on household income, which is defined in the SHS as that of the households highest income householder and their spouse or partner.
Organised in two-year cycles, it interviews around 15,000 households per annum and can provide data disaggregated at local authority level at the end of each cycle. The SHS is designed to be nationally representative every quarter, representative for larger Local Authorities ( LA) every year, and all LAs (regardless of size) over a two-year period. The SHS is a valuable source for LA level figures on a variety of topics including family income. As well as questions about income it collects information about several related areas such as 'use of credit' and sense of 'coping financially'. For more information see:
There are some definitional differences in the income questions asked in the SHS and FRS. Also, as the SHS asks questions about a variety of topics it inevitably asks less detailed income questions than the solely income-focussed FRS. Research looking at the differences between the two sources can be seen here: http://www.scotland.gov.uk/Topics/Statistics/16002/SHSIncPaper
It should be noted that the SHS only collects income information for the main householder, his/her partner and one random adult in the household. For many multi-adult households the SHS doesn't record income for some adults and therefore underestimates total household income. This means that SHS household income cannot be equivalised, and meaningful comparisons between households of different household types are difficult to make. In autumn 2008 the Scottish Government comissioned a feasibility study into the possibility of improving the quality of income estimates from the SHS by combining SHS and FRS data. The final report to this study can be found at the following link: SHS/FRS income study.
Local authority level estimates of the proportion of households with a net annual income of less than £10,000 are calculated from the SHS and published bi-annually (here: http://www.scotland.gov.uk/Topics/Statistics/Browse/Social-Welfare/IncomePoverty/LAdata). For the reason described above these figures are only presented for different household types and are not aggregated to complete local authority averages.
Annual Population Survey and Labour Force Survey
The Labour Force Survey is the official source of UK/Scottish labour market statistics such as employment, economic activity and unemployment. It is a face-to-face survey with a Scottish sample of around 8,000 households per annum. Official figures at a UK and Scottish Level are published monthly.
The Annual Population Survey is sourced from the annual Labour Force Survey data. The APS sample also includes a boost to the LFS sample which raises the Scottish sample size to around 23,000. Although the LFS is the official source of Scotland-level figures, the larger sample for the APS means that more robust labour market figures can be produced at a local authority level.
The APS does collect some information about income and earnings however this is self-assessed and is not recommended over that collected in other sources such as ASHE or the FRS. The robust local authority level estimates of employment and economic activity may be of interest to statistical users working in this area.
Scottish Index of Multiple Deprivation ( SIMD) Income Domain
The SIMD income domain use data from the Department for Work and Pensions to give the count or proportion of people defined as income deprived at a datazone level. 'Income deprived' people are those in the following categories:
- Adults and Children in Income Support ( IS) households
- Adults and Children in Job Seekers Allowance ( JSA) households
- Adults in Guaranteed Pension Credit households
SIMD is the official Scottish Government tool for highlighting areas of concentrated deprivation in Scotland and the income domain is used to highlight areas of income deprivation. This is a useful source for understanding the spread of income deprivation at a local level and data are availble at geographies down to datazone level. Users should note that some people highlighted as income deprived may not be in relative poverty according to the UK and Scottish Government definition (and vice versa). It is also worth noting that not all those living in an income deprived data zone will themselves be income deprived and likewise not all individuals who are income deprived will be living in areas with high concentrations of income deprivation.
There are some limitations to the SIMD income domain as it is a proxy indicator and, because the definition of 'income deprived' changes over time due to changes in the benefits system, it cannot be used to track changes over time. It is therefore of use as a proxy for a point in time but not for time series analysis. The SG is currently working with DWP to assess the possibility of producing annual updates to this domain to enable time series analysis.
SIMD data are available from www.sns.gov.uk and http://www.scotland.gov.uk/Topics/Statistics/SIMD/.
Working tax credit ( WTC) and child tax credit ( CTC) data from HM Revenue and Customs ( HMRC)
HMRC publish datazone level figures for
- Number of families benefiting from WTC, CTC and families with children receiving out of work benefits and
- Number of children in families benefiting from Tax Credits
These are available on the HMRC website at the following link: http://www.hmrc.gov.uk/stats/personal-tax-credits/ctc-small-areas.htm. At a local authority level the Scottish Government publish the 'Number and proportion of children living in households that are dependent on out of work benefits OR where Child Tax Credit is more than the family element' as a proxy for the number of children living in low income households. These figures can be calculated at a datazone level from these data. Proportions can be calculated by combining these figures with datazone level population figures from www.sns.gov.uk or the General Register Office for Scotland website.
Like the SIMD figures, these are used as a proxy for low income in small areas. They are released annually and, subject to changes to the tax credit system, can be used to track change over time. One limitation of using these figures as a proxy for low income households is that they only include people in full- or part-time employment or with children. Depending on their intended purpose, users may want to use these figures in combination with the SIMD income domain figures to get a more complete picture of the spread of tax credit and benefit claimants.
Commercial datasets - Caci Paycheck and Experian
Several commercial datasets are available, such as Caci Paycheck or Experian, which model household income at a postcode level. It is difficult to assess the robustness of commercial data as the coverage of the underlying datasets is unknown and details of these collection methodologies, being commercially sensitive, are often not available. Commercial datasets are not used in the calculation of SG income and poverty figures and users should satisfy themselves that they are suitable for a particular purpose before using them.