QUALITY DECLARATION - SUMMARY


INSTITUTIONAL ENVIRONMENT

For information on the institutional environment of the Australian Bureau of Statistics (ABS), including the legislative obligations of the ABS, financing and governance arrangements, and mechanisms for scrutiny of ABS operations, please see ABS Institutional Environment.


RELEVANCE

The Survey of Income and Housing (SIH) collects detailed information on income, wealth, housing, characteristics of individuals, income units and households from a sample of private dwellings throughout Australia. 

The survey collects information by personal interview from usual residents of private dwellings in urban and rural areas of not Very Remote Australia, covering approximately 97% of the people living in private dwellings in Australia. 

The survey facilitates the analysis and monitoring of the social and economic welfare of Australians in private dwellings. The main users are government and other social and economic analysts involved in the development, implementation and evaluation of social and economic policies.

Income and wealth data are used by economic and social analysts and policy makers to:

• understand the distribution of economic resources among private households in Australia;
• identify households most at risk of experiencing economic hardship; and
• understand the effects of taxation and welfare payments on people and families.

Housing data are used for:

• housing affordability studies;
• analysis of housing conditions and occupancy, including levels of home ownership and housing utilisation; and
• tracking changes in housing costs by tenure type over time.

TIMELINESS

The SIH is conducted every two years. The 2015–16 SIH collected information over the period July 2015 to June 2016.

The first results from the 2015–16 survey were released on 13^th September 2017, just over one year from the end of data collection. Subsequent outputs, including feature articles, other publications and Confidentialised Unit Record Files (CURF) will be released in late 2017.


ACCURACY

Final sample

In 2015–16, the SIH sample size was 17,768 households. The expansion of the sample (beginning in 2009–10 SIH) to include an extra 4,200 households located outside capital cities to better support COAG performance reporting was maintained. The SIH 2015–16 was run in conjunction with the Household Expenditure Survey (HES), including an additional pensioner sample, similar to the 2009-10 cycle.

Due to field performance not meeting design expectations, the sample in the first half of the financial year was smaller than expected. An additional sample was implemented in the second half of the 2015-16 financial year to bring the total sample in line with the design. Consequently, the survey sample is concentrated in the second half of the year. Weighting benchmarks for each quarter re-balance the sample.

See the User Guide and Explanatory Notes for more information about sampling and weighting.

To address partial non-response, data were imputed for missing fields. The final SIH sample includes 5,117 households (29% of households) and 8,079 person records (24% of persons aged 15 years or over) which had at least one imputed value. Imputation flags are provided at the module level in the CURF to allow users to identify and remove records with imputed data. Full record imputation is also used for households to impute data for some partially responding persons to minimise sample loss. Full record imputation is only undertaken for households where the main income earners in the household (e.g. both parents in a 'couple with children' household) have adequately completed the HES but others in the household (for example, children of those parents aged 15 years or over) have not. In 2015-16, 244 person level records were fully imputed, representing less than 1% of person records.

Reliability of the estimates

Estimates produced from the SIH are subject to two types of error: non-sampling error; and sampling error.

Non-sampling error

Non-sampling error can occur in any collection, whether the estimates are derived from a sample or from a complete collection such as a census. Sources of non-sampling error include non-response, errors in reporting by respondents or recording of answers by interviewers and errors in coding and processing the data.

Sampling error

The estimates are based on a sample of possible observations and are subject to sampling variability. The estimates may therefore differ from the figures that would have been produced if information had been collected for all households. A measure of the sampling error for a given estimate is provided by the standard error, which may be expressed as a percentage of the estimate (relative standard error).

The sample was designed to facilitate analysis at the part of state level with a high level of accuracy for the indicators from the SIH, including: Equivalised Disposable Household Income; Net Worth; and housing indicators. 


COHERENCE

The SIH provides baseline income and wealth information which provides a comparison point for the Census, and other ABS and external surveys. Selected comparisons with other ABS sources are provided in Datacube 25 'Data comparability between SIH and other ABS sources' available from the ‘Downloads’ tab of this publication. A comparison between items collected in the SIH and the Australian System of National Accounts will be provided on the Downloads tab of the User Guide. There are some differences between the SIH and these other sources for various reasons, including scope, coverage, period and definitional differences (standardised where possible), non-response, and potential under- and over-estimates of some items in the SIH.

Each cycle of the SIH collects comparable information to allow for analysis of changes over time.

Various statistics can be utilised to make comparisons between 2015–16 SIH data and data from previous SIH cycles. These include the Gini coefficient (a summary measure of income and wealth distribution and inequality), proportions (e.g. proportional share of income and wealth), means and medians. Wherever comparisons of prior cycles are made in the data cubes, CPI adjusted data has been provided to allow for analysis of real change after inflation is taken into account.

The ABS seeks to maximise consistency and comparability over time by minimising changes to the survey. Sound survey practice, however, requires ongoing development and maintenance to maintain the integrity of the data and the efficiency of the collection. Current income and wealth standards are available on the ABS website and more information is available in the Explanatory Notes of this publication and the User Guide publication.


INTERPRETABILITY

Detailed information on the terminology, classifications and other technical aspects associated with the SIH can be found in the Explanatory Notes and Glossary included with this publication. The User Guide (cat. no. 6503.0) will be released in October 2017.


ACCESSIBILITY

Tabulated data and associated relative standard errors are freely available in Excel spreadsheets which can be accessed from the 'Downloads' tab. 

A CURF product will be produced from the SIH, subject to the approval of the Australian Statistician. For further details, refer to the Microdata Entry Page on the ABS website. It is expected that the CURF products will be available in late 2017. A Survey TableBuilder product is also planned to be available in late 2017.

Customised data are also available on request. Note that detailed data can be subject to high relative standard errors which in some cases may result in data being regarded as unfit for release. A data item list is available from the 'Downloads' tab of the User Guide for 2015–16 (cat. no. 6503.0).

For further information about these or related statistics, contact the National Information and Referral Service on 1300 135 070, or email client.services@abs.gov.au. The ABS Privacy Policy outlines how the ABS will handle any personal information that you provide to us.