Data Collection and Processing
Trained ABS interviewers were used to collect Survey of Income and Housing (SIH) from July 2019 to March 2020. They were given comprehensive training and were provided with detailed written instructions to complement the survey documents. Face-to-face interviewing was ceased early from March 2020 to June 2020 during the COVID-19 pandemic, the survey was collected online or via telephone interviewing only. There was no face-to-face interviewing conducted from late March 2020 due to COVID-19 restrictions
Information for each household was collected using:
- a household level computer assisted personal interview questionnaire or computer assisted web interview which collected information on household characteristics, housing costs, expenditure common to all household members (e.g. utility bills), and irregular or infrequent expenditure (e.g. household appliances and holidays overseas) and certain assets and liabilities for all households;
- an individual level computer assisted personal interview questionnaire or computer assisted web interview which collected information on income, certain assets and liabilities, and personal characteristics from each usual resident aged 15 years and over in all households.
For SIH interviews, the interviewer:
- made an initial contact visit, in which they obtained information on the numbers and characteristics of people usually resident in the dwelling. If a responsible adult was not available, the interviewer called back at another time. The interviewer also arranged a convenient time to call back to conduct the interviews;
- completed one household questionnaire for each household (information was provided by a household spokesperson who was nominated as the best person to provide information on the financial situation of the household);
- completed an individual questionnaire for each usual resident aged 15 years and over; and
- completed a proxy interview when the parent/guardian of children in the household aged 15–17 years, did not give permission for them to be personally interviewed, or when a person was incapable of answering on their own behalf.
- From 1 July 2019 to March 2020, respondents had an option of completing the survey via computer assisted web interview, face to face interview or telephone interview. During the COVID-19 pandemic, households had the option of either completing the survey online, or via a telephone interview. An invitation was made for selected households to participate online which included a letter in the post with instructions for completing the survey online. A few weeks were allowed for a household to respond online. Households that were unable to complete the survey online were able to complete the survey with an interviewer over the telephone. There was no face-to-face follow up for households that did not complete the survey.
For details of the data items available from the 2019–20 SIH see the Excel spreadsheet available as a data cube from the 'Data Downloads' section of this publication.
Data processing and derivations
Data processing methods
Computer based systems were used to collect and process the data from the 2019-20 SIH with a software program known as ConfirmIT. A variety of methods were employed to process and edit the data, reflecting the different questionnaires used to collect data from the household and individual components of the surveys. These processes are outlined below:
Coding and input editing of household and individual questionnaires
Internal system edits were applied in the CAI and CAWI questionnaires to ensure the completeness and consistency of the responses being provided. The interviewer/selected person could not proceed from one section of the interview to the next until responses had been appropriately completed.
A number of range and consistency edits were programmed into the CAI and CAWI questionnaire. Edit messages automatically appeared on the screen if the information entered was either outside the permitted range for a particular question, or contradicted information already recorded. These edit queries were resolved on the spot with respondents.
Data from the CAI questionnaires were electronically loaded to the processing database on receipt in the ABS office. Office checks were made to ensure data for all relevant questions were fully accounted for and that returns for each household and respondent were obtained. Problems identified by interviewers were resolved by office staff, where possible, based on other information contained in the schedule, or on the comments provided by interviewers.
Computer-assisted coding was performed on responses to questions on country of birth, occupation and industry of employment and language to ensure completeness. Data on relationships between household members were used to delineate families and income units within the household, and to classify households and income units by type.
A range of edits was also applied to the household and individual information to double check that logical sequences had been followed in the questionnaires; that specific values lay within expected ranges; and that relationships between items were consistent. Unusually high values (termed statistical outliers) were investigated to determine whether there had been errors in entering the data and corrections were made where necessary.
Imputation for missing records and values
Some households did not supply all the required information but supplied sufficient principal information to be retained in the sample. Such partial responses occur when:
- income or other data in a questionnaire are missing from one or more non-significant person's records because they are unable or unwilling to provide the data,
- all key questions are answered by the significant person(s) but other questions are not answered. Significant person(s) are the main income earners for the household (e.g. both parents in a couple family with children household, half of all persons in a group household, see glossary for further information)
In the two cases of partial response above, the data provided are retained and the missing data are imputed by replacing each missing value with a value reported by another person with similar characteristics, referred to as the 'donor'.
Donor records are randomly selected by finding fully responding persons with matching information on multiple characteristics, such as state, sex, age, labour force status and income, as the person with missing information. As far as possible, the imputed information is an appropriate proxy for the information that is missing. Depending on which values are to be imputed, donors are randomly chosen from the pool of individual records with complete information for the block of questions where the missing information occurs.
The final SIH sample includes 2,178 households (15% of households) and 11,421 person records (39% of persons aged 15 years or over) which had at least one imputed value.
Modelled data items
Some data items of interest cannot reliably be collected from respondents, and some cannot be collected at all. However, it is sometimes possible to utilise other information provided by respondents as a basis for estimating the data items of interest. This process is referred to as modelling.
The Child Care Subsidy (CCS) is the main way in which the Australian Government helps families with child care fees. The CCS replaced two previous payments: the Child Care Benefit and the Child Care Rebate.
The level of CCS a family receives depends on three factors: family income, activity and the service type used. It is generally paid directly to care providers who pass the subsidy on to families through a fee reduction. Families therefore pay the difference between the provider’s fee and the subsidy amount. Families can receive CCS for a maximum of 50 hours per week.
Additional Child Care Subsidy
A supplementary payment was introduced at the same time as the CCS, the Additional Child Care Subsidy (ACCS). The ACCS provides top up assistance in addition to the CCS for children at risk of abuse or neglect, families experiencing financial hardship, families transitioning to work from income support, grandparent carers on income support. The ACCS is equal to 100 percent of the actual fee charged or up to 120 percent of the hourly rate cap, for up to 100 hours of assistance per fortnight. The ACCS replaced a number of previous payments including the Special Child Care Benefit, Grandparent Child Care Benefit and the Jobs, Education and Training Child Care Fee Assistance payment.
Estimates of Child Care Subsidy (CCS) are collected from the child care questions, historically there has been a substantial gap between the reported number of households receiving child care subsidies and the total value of that assistance, compared to administrative records. CCS has been modelled to improve the accuracy of estimates of these payments. The output data is made up of both reported and modelled data.
The modelled amounts of CCS is available at both the household and income unit level.
Income tax and the Medicare levy and levy surcharge
Disposable income is calculated by deducting income tax, including the Medicare levy, from gross income.
The model is based on the liability rules described in the Tax Pack from the Australian Tax Office for the year concerned, the income reported by respondents, and other characteristics of household members reported in the survey.
Estimates of income tax are modelled, rather than collected from respondents, for a number of reasons including:
- An accruals approach is taken to estimating these items. The estimates relate to the tax liability being incurred with respect to the income being reported by the respondent in the survey. For estimates of current income, the current income tax liability is calculated as though the current income is the average income for the whole year. If actual income fluctuates during the year, respondents are unlikely to have an actual income tax assessment that is relevant to the required estimate.
- In addition to income changes during the course of the year, full year income tax assessments may be affected by changes in family or other circumstances of the respondent which are not described in the survey, and are best ignored when deriving an income tax estimate to use with the other survey data.
- Income tax assessments are only made after the end of the financial year, and therefore are not yet available at the time that current income is collected from respondents.
- The income tax assessment of respondents may be affected by certain expenditures which they make, such as donations to charities or other particular circumstances which are not captured in the survey. For many purposes it is desirable to exclude the impact on tax liabilities of specific influences which are not captured in the survey.
- The SIH provides sufficient relevant information to allow a relatively comprehensive tax model to be constructed.
The Medicare levy surcharge were also modelled and deducted from gross income in the calculation of disposable income.
For more information see the 'Income' section of this publication.
Governments payment modelling
The eligibility-based modelling designed by the Department of Social Services (DSS) was introduced by the ABS in the 2015–16 SIH cycle. For the 2019–20 SIH, there were minor changes made to reflect policy and rate changes, and the types of payments available from DSS. Improvements to the accuracy of Family Tax Benefit were also included utilising the new (experimental) questions about children's living arrangement. Information about pension supplements was not asked of households, this information is entirely modelled.
Information about the model is available in Household Expenditure Survey and Survey of Income and Housing, User Guide, Australia - 2015-16.
Receipts of Family Tax Benefit are treated as income, regardless of whether they are received fortnightly or as a lump sum. The Newborn Supplement and Newborn Upfront Payment for those eligible receive it as part of their Family Tax Benefit Part A payments for a period of 13 weeks or with their lump sum. The Paid Parental Leave payment has also been included as income.
The Energy Supplement is included in income from government pensions or allowances. This tax-exempt, indexed payment is paid to pensioners, other income support recipients, families receiving Family Tax Benefit payments and Commonwealth Seniors Health Card holders, provided they meet eligibility requirements.
Government payments such as the $550 fortnightly, Coronavirus Supplement and the annual $750, Economic Support Payment were introduced to provide social assistance during the COVID-19 pandemic. Separate to this model, eligible Coronavirus Supplement recipients were allocated $275 per week to their total government payments from April 27 2020 onwards. Eligible Economic Support Payment recipients were allocated an annualised amount of approximately $14 per week to their total government payments. The JobKeeper payment is not considered a government payment nor allowance as it was paid to employers via the Australian Tax Office.