Microdata and TableBuilder: Australian Census Longitudinal Dataset

The Australian Census Longitudinal Dataset (ACLD) uses Census of Population and Housing data to build a rich longitudinal view of Australian society

Introduction

The Census of Population and Housing is conducted every five years to measure the number of people and dwellings in Australia on Census Night. The Census also provides information on the key characteristics of people and dwellings for small geographic areas and small population groups.

The Australian Census Longitudinal Dataset (ACLD) uses data from the Census of Population and Housing to build a rich longitudinal picture of Australian society. The ACLD can uncover new insights into the dynamics and transitions that drive social and economic change over time, and how these vary for diverse population groups and geographies.

Three waves of data have so far contributed to the ACLD from the 2006 Census (Wave 1), 2011 Census (Wave 2) and 2016 Census (Wave 3).

There are two ACLD panels, representing a 5% sample of records from the 2006 Census and the 2011 Census respectively. The 2006 Panel comprises records from the original 2006 ACLD sample linked to records from the 2011 Census and the 2016 Census. The 2011 Panel is linked to records from the 2016 Census.

There are three ACLD datasets: 

  • the original 2006-11 linkage released in 2013, and updated in 2016 with three Visa data items from the Department of Social Services’ Settlement Database
  • the 2011-16 linkage which includes an updated 2011 Panel to account for births and migrants since the 2006 Census
  • the 2006-11-16 linkage which includes a relink of the 2006 Panel to the 2011 Census to take advantage of improved linking methodology since the initial release, and has then been linked to records from the 2016 Census.

Microdata products are the most detailed information available from a Census or survey and are generally the responses to individual questions on the questionnaire. They also include derived data from answers to two or more questions and are released with the approval of the Australian Statistician.

Available products

DataLab - for in-depth analysis using a range of statistical software packages

  • Australian Census Longitudinal Dataset, 2006-11-16
  • Australian Census Longitudinal Dataset, 2011-2016
  • Australian Census Longitudinal Dataset, 2006-2011

TableBuilder - an online tool for creating tables and graphs

  • Australian Census Longitudinal Dataset, 2006-11-16
  • Australian Census Longitudinal Dataset, 2011-2016
  • Australian Census Longitudinal Dataset, 2006-2011

Further information about TableBuilder and DataLab, and other information to assist users in understanding and accessing microdata in general, is available from the Microdata Entry Page.

Applying for access

Before applying for access to TableBuilder, users should read and familiarise themselves with the information contained in the TableBuilder User Guide (cat. no. 1406.0.55.005).

To apply for access to TableBuilder, please register and apply from the How to Apply for Microdata page on the ABS website.

Information about TableBuilder can be found on the Microdata Entry Page.

If you already are a registered TableBuilder user Login in here.

To apply for access to the ACLD in DataLab, please contact Microdata Access Strategies via microdata.access@abs.gov.au.

Information about the DataLab can be found on the About the DataLab page.

Support

For support in the use of this product, please contact Microdata Access Strategies on 02 6252 7714 or via microdata.access@abs.gov.au.

Data available on request

Customised tables are available on a fee-for-service basis. A consultancy service is available for complex analysis and modelling. For further information, contact the National Information and Referral Service on 1300 135 070 or email client.services@abs.gov.au.

Further information

Further information about the Australian Census Longitudinal Dataset can be found on the ACLD page.

Further information about ABS statistical data integration is available on the ABS Data Integration page.

Inquiries

For further information about these and 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.

Methodology

Scope and coverage

The ACLD is a random 5% sample of persons enumerated in Australia on each Census Night, and linked together using statistical techniques. Three waves of data have contributed to the ACLD so far, from the 2006, 2011 and 2016 Censuses.

The Census covers all areas in Australia and includes persons living in both private and non-private dwellings but excludes: 

  • diplomatic personnel of overseas governments and their families
  • Australian residents overseas on Census Night

Overseas visitors are excluded from the 2011 ACLD sample. Visitors within Australia to private and non-private dwellings on Census Night are included.

For more information on the scope and coverage of the Census:

Sample design

In preparation for adding 2016 Census data to the ACLD, a new panel of 2011 Census records was selected as a representative sample of the 2011 population. The 2011 Panel was designed to include most of the 2011 Census records that were linked in the 2006 Panel, with new records added to account for missed links in the 2006 Panel, and new births and migrants since the 2006 Census.

Sample maintenance

Without sample maintenance, the ACLD would decline in its ability to accurately reflect the Australian population over time, due to:

  • people newly in scope of the ACLD (i.e. children born and immigrants who arrived in Australia since the previous Census) not being represented in the sample,
  • people no longer being in scope due to death or overseas migration, and
  • missing and/or incorrect links.

The 2011 Panel sample was increased slightly to 5.7%, to achieve a linked sample size of no greater than 5% of the population, after allowing for missed links and people no longer being in scope due to death or overseas migration. The 2011 panel sample of over one million records (1,221,057) from the 2011 Census was linked to the 2016 Census, resulting in a linked sample size of 927,520 records at a linkage rate of 76%. This achieved a linked sample size of 4.3%.

Multi panel sample method

The ACLD sample is maintained through the application of the Multi-Panel framework, which provides an approach for selecting records in the ACLD to create panels that maintain the longitudinal and cross-sectional representativeness of the dataset over time, while minimising the impact of accumulated linkage bias on longitudinal analysis.

The Multi-Panel framework is comprised of multiple overlapping panels, with each panel representing a single Census population (2006, 2011, 2016, etc.). Each Census year a panel is selected and linked to subsequent Censuses. The sample selection strategy for each panel is designed to maintain a linked sample size of 5%, maximise sample overlap between the panels, and introduce new records to the dataset in each panel to account for new births, migrants and missed links in previous panels.

This allows flexibility for users, who can draw on the most appropriate panel for their research question.

For further information on the Multi-Panel framework refer to Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016 (cat. no. 2080.5).

Linking methodology

Linking strategy

Data from the ACLD Panel samples and the Census files were brought together using data linkage techniques.

Data linkage is typically undertaken using deterministic and/or probabilistic methods:

  • Deterministic linkage: involves assigning record pairs across two datasets that match exactly or closely on common variables. This type of linkage is most applicable where the records from different sources consistently report sufficient information and can be an efficient process for conducting linkage.
  • Probabilistic linkage: is based on the level of overall agreement on a set of variables common to the two datasets. This approach allows links to be assigned in spite of some missing or inconsistent information, providing there is enough agreement on other variables.

Linking variables

The variables on Census files that were used for linking include:

  • First name hash code
  • Surname hash code
  • Age
  • Sex
  • Date of birth
  • Indigenous status
  • Country of birth
  • Year of arrival
  • Marital status
  • Religion
  • Language spoken
  • Mother's age
  • Mother's day and month of birth
  • Mother's country of birth
  • Father's age
  • Father's day and month of birth
  • Father's country of birth
  • Mesh block
  • Statistical Areas 1, 2 and 4.

A number of linkage passes were conducted based on different combinations of these variables to ensure each record had the highest possible chance of being linked.

For more information about the linking variables used, see:

There were two main reasons why some records were not linked across Census files:

I. Records belonging to the same individual were present at both time points but these records failed to be linked because they contained missing or inconsistent information.
II. The person had no record in the later Census.

For detailed information on the linking methodology and an assessment of its quality see Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016 (cat. no. 2080.5).

To protect the privacy of Census respondents, we used an ABS encoded Census name for linking 2011 and 2016 Census records in the ACLD. Encoding was undertaken in 2011 for the purpose of protecting privacy by anonymising name and improving the future quality and efficiency of the linking process.

The codes are created by grouping people with a combination of letters from their first and last names using a secure one-way process, meaning that a code cannot be reversed to deduce the original name information. Each code represents approximately 2,000 people drawn from many different letter combinations, and therefore is not unique to an individual. Actual name information from the 2016 Census was not used to link to 2011 Census records.

For further information, see Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016 (cat. no. 2080.5).

At the end of the linkage processes:

  • 800,759 (82%) of the 979,661 sample records from the 2006 Panel were linked to a 2011 Census record on the original 2006-11 linkage dataset
  • 927,520 (76%) of the 1,221,057 sample records from the 2011 Panel were linked to a 2016 Census record
  • 756,945 (77%) of the 979,662 sample records from the 2006 Panel were linked to a 2011 Census record, to form the relinked 2006-11 portion of the 2006-11-16 file. These record pairs were then linked to the 2016 Census via the 2011 Census record in each pair, which achieved 605,618 links (80% of the 2011 records in the 2006 Panel). Of links from the 2006 Panel sample, 62% linked to both the 2011 and 2016 Censuses.

Weighting, benchmarking and estimation

Weighting

Weighting is the process of adjusting a sample to infer results for the relevant population. To do this, a 'weight' is allocated to each sample unit - in this case, persons. The weight can be considered an indication of how many people in the relevant population are represented by each person in the sample. Weights were created for linked records in the ACLD to enable longitudinal population estimates to be produced.

Each Panel of the ACLD is a random 5% sample of persons enumerated in Australia on Census Night. As such, each person in the sample should represent about 20 people in the Australian population. Between Censuses, however, the Australian population in scope of the ACLD changes as people die or move overseas. In addition, Census net undercount and data quality can affect the capacity to link equivalent records across waves.

The ACLD weights benchmark the linked records to the estimated Australian in scope population. The weights were based on four components: the design weight, undercoverage adjustment, missed link adjustment and population benchmarking.

For the 2006-11 weight, the original population benchmark was the 2011 Estimated Resident Population (ERP). The 2011 ERP was chosen over the 2006 ERP as the baseline population is more recent. The 2011 ERP was then adjusted to exclude people who were not in Australia in 2006.

For the 2011-16 weight, the population benchmark is based on the 2016 Estimated Resident Population (ERP). This population benchmark was adjusted by the estimated probability that a person was also in Australia in 2011. This probability was estimated using the 2016 Census 'reported 5 year ago address' variable.

For the 2006-2011-2016 weight, the population benchmark is based on the 2011 and 2016 Estimated Resident Population (ERP), which is adjusted by the estimated probability a person belongs to the longitudinal population. This probability is formed using the Census reported address five year ago variable from the 2011 or 2016 Census.

Weights were benchmarked to the following population groups:

  • state/territory by age (ten year groups) by sex by mobility (interstate arrivals benchmarked separately), and
  • Indigenous status by state/territory.

The 2006-11 weights (original 2006-11 dataset) have a mean value of 24 and range between 17 and 103. Higher weights are associated with people of Aboriginal and Torres Strait Islander origin, and people who moved interstate between 2006 and 2011.

The 2006-11 (re-link) weights available on the 2006-11-16 DataLab file have a mean value of 25.0 for females and 26.6 for males. The weights range between 16.1 and 176.9. The mean weight was higher for Aboriginal and Torres Strait Islander persons and for people in the Northern Territory.

The 2006-11-16 weights have a mean value of 29.4 for females and 31.5 for males. The weights range between 15.9 and 341.3. The mean weight was higher for Aboriginal and Torres Strait Islander persons and for people in the Northern Territory.

The 2011-16 weights have a mean value of 22.3 for females and 23.2 for males. The weights range between 14.8 and 83. The mean weight was higher for Aboriginal and Torres Strait Islander persons and for people in the Northern Territory.

Estimation

Estimates of population groups are obtained by summing the weights of persons with the characteristic(s) of interest.

For further information about ACLD weighting and estimation refer to Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016 (cat. no. 2080.5).

Sources of error

All reasonable attempts have been taken to ensure the accuracy of the longitudinal dataset. Nevertheless potential sources of error including sampling, linking and Census quality error should be kept in mind when interpreting the results.

Sampling error

Sampling error occurs because only a small proportion of the total population is used to produce estimates that represent the whole population. Sampling error refers to the fact that for a given sample size, each sample will produce different results, which will usually not be equal to the population value.

There are two common ways of reducing sampling error - increasing sample size and/or utilising an appropriate selection method (for example, multi-stage sampling would be appropriate for household surveys). Given the large sample size for the ACLD (1 in 20 persons), and simple random selection, sampling error is minimal.

Linking accuracy

False links can occur during the linkage process as even when a record pair matches on all or most linking fields, it may not actually belong to the same individual. While the methodology is designed to ensure that the vast majority of links are true, some are nevertheless false. The nature of the process used for the ACLD linkage means that while the links obtained are to a high degree of accuracy, some false links may be present within the ACLD dataset. There is an estimated 5-10% false link rate in the original linkage of the 2006-2011 ACLD linkage, an estimated 5% false link rate in the re-link of the 2006-2011 ACLD linkage and an estimated 1% false link rate in the 2011-2016 ACLD linkages.

For further detail on the accuracy of the linkage, see Linkage Results sections in to Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016 (cat. no. 2080.5).

Managing Census Quality

The ABS aims to produce high quality data from the Census. To achieve this, extensive effort is put into Census form design, collection procedures and processing procedures.

There are four principle sources of error in Census data: respondent error, processing error, partial response and undercount. Quality management of the Census program aims to reduce error as much as possible, and to provide a measure of the remaining error to data users, to allow them to use the data in an informed way.

Information about the quality of the 2006, 2011 and 2016 Census data is available on the Data Quality page on the ABS website.

The Census Independent Assurance Panel concluded that the 2016 Census data is of comparable quality to 2011 and 2006 Census data so may be used with confidence. Information is available in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

For more detail see Managing Census Quality, in Census of Population and Housing: Census Dictionary, 2016 (cat. no. 2901.0).

Respondent error

For most households in Australia, the Census is self-enumerated. This means that householders are required to complete the Census form themselves, rather than having the help of a Census collector. The Census form may be completed by one household member on behalf of others. Error can be introduced if the respondent does not understand the question, or does not know the correct information about other household members. Self-enumeration carries the risk that wrong answers could be given, either intentionally or unintentionally.

Processing error

Much of the data on the Census form is recorded using automatic processes, such as scanning, Intelligent Character Recognition and other automatic processes. Quality assurance procedures are used during Census processing to ensure processing errors are kept at an acceptable level. Sample checking is undertaken during coding operations, and corrections are made where necessary.

Partial response

When completing their Census form, some people do not answer all the questions which apply to them. While questions of a sensitive nature are generally excluded from the Census, all topics have a level of non-response. This can be measured and is generally low. In those instances where a householder fails to answer a question, a 'not stated' code is allocated during processing, with the exception of non-response to age, sex, marital status and place of usual residence. These variables are needed for population estimates, so they are imputed using other information on the Census form, as well as information from the previous Census.

Undercount

The goal of the Census is to obtain a complete measure of the number and characteristics of people in Australia on Census Night and their dwellings, but it is inevitable that a small number will be missed and some will be counted more than once. In Australia more people are missed from the Census than are counted more than once, thus the effect when both factors are taken into account is a net undercount.

For more detail see Managing Census Quality, in Census of Population and Housing: Census Dictionary, 2016 (cat. no. 2901.0).

Data consistency

A small percentage of linked records have inconsistent data, such as a different country of birth at the two time points or an age inconsistency of more than one year (when the expected five year difference is accounted for). Inconsistencies may be due to:

  • false link - the record pair does not belong to the same individual
  • reporting error - information for the same individual was reported differently at different time points
  • processing error - the value of a data item was inaccurately assigned or imputed during processing.

In most analysis, the effect of inconsistent information may only have a small impact. Characteristics from the 2006, 2011 or the 2016 data can be used in tables and some exploration of consistency over time will assist in drawing appropriate conclusions.

No data editing was applied to the file beyond that which had already taken place during the relevant Census processing period. A set of consistency flags has been included on the ACLD file so that inconsistent data may be observed, quantified or excluded from calculations. Consistency flags, located in the Quality Indicators group of data items, have been created for Census variables that would not be expected to change over time or have unlikely transitions over time. These are as follows:

  • Age
  • Sex
  • Country of Birth
  • Birthplace of Person
  • Birthplace of Female Parent
  • Birthplace of Male Parent
  • Year of Arrival
  • Indigenous Status
  • Registered Marital Status
  • Highest Year of School Completed
  • Level of Highest Non-School Qualification
  • Country of Birth of Spouse or Partner
  • Number of Children Ever Born.

There are numerous ways to define 'consistency'. The consistency flags have fine level categories to allow users flexibility in using their own definition of 'consistent' or 'inconsistent'. For example, where one Census has 'not stated' for the year of arrival data item, a user can decide whether the record should be considered consistent or not. The same applies to where the response for one Census is 'not applicable'. The labels attached to each category suggesting consistency or inconsistency will assist the user in determining which records are consistent or inconsistent for their needs. The tables below use the relevant labels to define inconsistency.

See also Quality Indicators in the Data Items sections.

Inconsistent reporting on the original 2006-2011 linked ACLD file, by selected characteristics
CharacteristicProportion of linked records with
inconsistent data between 2006 and 2011 (a)
Age (by more than 1 year)2.41%
Sex0.11%
Birthplace of person2.09%
Birthplace of female parent4.01%
Birthplace of male parent4.41%
Year of arrival (b)17.86%
Indigenous status0.53%
Registered marital status0.71%
Highest year of school completed6.27%
Level of highest non-school qualification14.86%
Country of birth of spouse or partner (b)3.85%
Number of children ever born2.79%
  1. Excludes records where a relevant data item was not stated, inadequately described or not applicable in both years.
  2. Excludes records where a response was not applicable one year and applicable the other.
Inconsistent reporting on the linked 2006-11-16 ACLD file, by selected characteristics
CharacteristicProportion of linked records with
inconsistent data between 2006 and 2011 (a)
Age (by more than 1 year)0.42%
Sex0.05%
Birthplace of person2.12%
Birthplace of female parent2.58%
Birthplace of male parent2.75%
Year of arrival (b)13.24%
Indigenous status0.74%
Registered marital status0.46%
Highest year of school completed7.15%
Level of highest non-school qualification14.44%
Country of birth of spouse or partner (b)3.01%
Number of children ever born1.87%
  1. Excludes records where a relevant data item was not stated, inadequately described or not applicable in both years.
  2. Excludes records where a response was not applicable one year and applicable the other.
Inconsistent reporting on the 2011-2016 linked ACLD file, by selected characteristics
CharacteristicProportion of linked records with
inconsistent data between 2011 and 2016 (a)
Age (by more than 1 year)0.92%
Sex0.16%
Birthplace of person1.23%
Birthplace of female parent1.60%
Birthplace of male parent1.90%
Year of arrival (b)15.94%
Indigenous status0.83%
Registered marital status0.54%
Highest year of school completed6.57%
Level of highest non-school qualification12.87%
Country of birth of spouse or partner (b)1.72%
Number of children ever born1.10%
  1. Excludes records where a relevant data item was not stated, inadequately described or not applicable in both years.
  2. Excludes records where a response was not applicable one year and applicable the other.
Inconsistent reporting on the linked 2006-11-16 ACLD file, by selected characteristics
CharacteristicProportion of linked records with
inconsistent data between 2011 and 2016 (a)
Age (by more than 1 year)0.63%
Sex0.10%
Birthplace of person1.03%
Birthplace of female parent1.49%
Birthplace of male parent1.82%
Year of arrival (b)15.53%
Indigenous status0.70%
Registered marital status0.44%
Highest year of school completed6.47%
Level of highest non-school qualification12.56%
Country of birth of spouse or partner (b)1.45%
Number of children ever born0.99%
  1. Excludes records where a relevant data item was not stated, inadequately described or not applicable in both years.
  2. Excludes records where a response was not applicable one year and applicable the other.

ACLD 2006-11-16

Product overview

The 2006-11-16 ACLD is a representative sample of almost one million records from the 2006 Census (Wave 1) brought together with corresponding records from the 2011 Census (Wave 2) and the 2016 Census (Wave 3).

The 2006 Panel sample of records was originally linked to the 2011 Census and released in 2013. In this release, the 2006 Panel has been re-linked to the 2011 Census to take advantage of improved linking methodology since the initial release, and has then been linked to records from the 2016 Census.

The 2006-11-16 ACLD product is recommended for analysis of the 2006-11 and 2006-11-16 longitudinal populations.

Note: While the 2011 and 2016 Censuses were predominantly the same, there were some minor differences. For example, a number of changes were made to how industry of employment information was collected for the 2016 Census. The ABS advises this data is not directly comparable to 2011 industry data and should not be used to measure longitudinal transitions. For further information refer to Industry of Employment (INDP) in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

Users are also encouraged to read Understanding the data pages in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0) for information to assist with using and interpreting specific data items across time.

Inquiries

For further information about these and 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.

Data items

Data items list

A complete list of data items included on the ACLD file is provided in an Excel spreadsheet that can be accessed from the Data downloads section.

All data items are created at the person level. This includes data items relating to the family and household of the person selected in the sample. For ease of use, these data items have been divided into Person, Dwelling, Household, Family, Spouse Related, and Male and Female parent related groupings.

Users intending to subscribe to the TableBuilder product or use the microdata product in the DataLab should first refer to the Data Items List to ensure the data they require, and the level of detail required, are available and applicable for the intended use.

For information about the quality of the data items in the ACLD please see the Quality Declaration.

Note: While the 2011 and 2016 Censuses were predominantly the same, there were some minor differences. For example, a number of changes were made to how industry of employment information was collected for the 2016 Census. The ABS advises this data is not directly comparable to 2011 industry data and should not be used to measure longitudinal transitions. For further information refer to Industry of Employment (INDP) in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

Visitors on Census night

Overseas visitors were excluded from the 2006 ACLD sample. The ACLD, however, does include visitors from within Australia. These are people who were enumerated away from their usual residence on Census Night. Family information cannot be derived for these persons and as such, all family, spouse, and male and female parent related data items are not applicable for visitors.

All dwelling related data items, however, have been made applicable to visitors. This information relates to their dwelling of enumeration on Census Night, not usual residence.

Most household data items are not applicable to visitors, however for four data items, visitors have been included in order to align to standard Census derivations of that data item. These comprise: 

  • Total Household Income as stated (weekly) of household in which person was enumerated
  • Total Household Income (weekly) of household in which person was enumerated
  • Household Income Derivation Indicator of household in which person was enumerated
  • Household Composition of household in which person was enumerated.

Any applicable household information for a visitor relates to their place of enumeration, not usual residence.

Where a data item is also applicable to visitors, the usual address indicator data item for the relevant Census year can be used to restrict the table to usual residents only.

The cell comments available in the data item list provide precise information on who is, and is not, applicable for each data item.

Persons temporarily absent on Census night

The Census household form provides the opportunity to list up to three persons who were temporarily absent from the dwelling on Census Night. A limited amount of information is collected for these persons and it is used to better derive the family and household characteristics of the dwelling. In deriving family and household related data items for the ACLD, information on persons temporarily absent was included where relevant and available. Details are provided in cell comments in the data items list.

Not applicable categories

Most data items in the ACLD include a 'not applicable' category. The definition of the 'not applicable' category, where relevant, can be found in the section of the relevant year's Census Dictionary (cat. no. 2901.0), including the previous year releases found in the "Past & Future Releases" list.

Not stated categories

'Not stated' categories occur when no response has been provided for a data item. All Census data items contain 'not stated' categories except for age, sex, marital status and usual address, as this information is imputed for these items.

Other Census products commonly use the symbol '&' to denote a code value of 'not stated'. In the ACLD, the symbol 'X' or '97' has been used. The codes are listed in the data items list.

Quality indicators

The ACLD contains a number of data items that relate to the quality of linkage over the period 2006 to 2011, and 2011 to 2016 and have been collectively named Quality Indicators. The first of these are consistency flags. These variables measure the consistency of reporting on linked records between the time points. The following consistency flags can be found in the Quality Indicators folder of the TableBuilder data item tree and in the ACLD microdata product available in the DataLab:

  • Age
  • Sex
  • Birthplace of Person
  • Birthplace of Female Parent
  • Birthplace of Male Parent
  • Year of Arrival
  • Indigenous Status
  • Registered Marital Status
  • Highest Year of School Completed
  • Hours worked
  • Level of Highest Non-School Qualification
  • Country of Birth of Spouse or Partner
  • Number of Children Ever Born.
Image: Screen shot from TableBuilder showing the Consistency Flags data items under the Quality Indicators folder.

Consistency flags can be used with other variables. For example, age inconsistency can be cross tabulated with sex to examine potential gender differences in the reporting of age.

Screen shot from TableBuilder showing Age Consistency flag cross-tabulated with Sex of person in 2016. The rows show number of people with age consistent within 0 years, 1 year, and so on to 10 or more years, by males, females, and totals in the columns.

In addition to the consistency flags, "Record linked in 2011” and “Record linked in 2016” flags are also available. These flags can be cross tabulated with other data items to examine linkage rates (that is, the proportion of records linked). For example, cross tabulating the record linked flag with State/Territory of usual residence enables an examination of differences in linkage rates between the states and territories.

Image: Screen shot from TableBuilder showing "State/territory of usual residence in 2006" cross-tabulated with "Record linked in 2011" to show linkage rates by State/territory. For example, linkage rate for NSW is 77.39%, Australia total is 77.27%.
Image: Screen shot from TableBuilder showing "State/territory of usual residence in 2006" cross-tabulated with "Record linked 2011 to 2016" for records linked from 2006 to 2011. For example, linkage rate for NSW is 79.74%, Australia total is 80.01%.

Weights

The 2006-11-16 TableBuilder file has one weight to benchmark the linked records to the estimated Australian population that was in scope of the 2006, 2011 and 2016 Censuses.

The 2006-11-16 DataLab file has two weights:

  • a 2006-11 weight to benchmark the linked records to the estimated Australian population that was in scope of the 2006 and 2011 Censuses
  • a 2006-11-16 weight to benchmark the linked records to the estimated Australian population that was in scope of the 2006, 2011 and 2016 Censuses.

File structure

The 2006-11-16 ACLD datasets in both TableBuilder and DataLab are single-level files that count persons.

In TableBuilder, data items have first been separated by year of collection. For each year, data items are further divided into the following groups:

  • Person - person-level characteristics, covering demographic, culture and language, education, employment and unpaid work topics.
  • Family - derived from the characteristics of the family to which the person belongs on Census Night - e.g., age of youngest child in family.
  • Household - derived from the characteristics of the household to which the person belongs on Census Night - e.g., total weekly household income.
  • Dwelling - derived from the characteristics of the dwelling in which the person was enumerated - e.g., type of dwelling.
  • Female Parent - derived from information about the person's female parent, provided the parent was counted in the same family on Census Night - e.g., labour force status of female parent.
  • Male Parent - derived from information about the person's male parent, provided the parent was counted in the same family on Census Night - e.g., labour force status of male parent.
  • Spouse or Partner - derived from information about the person's spouse/partner, provided the spouse/partner was counted in the same family on Census Night - e.g., highest educational attainment of spouse/partner.
  • Geographical Area - geographic classifications on both a usual residence and place of enumeration basis.

There is also a group of items named Quality Indicators, which are consistency flags, imputation flags and movement indicators to assist with the assessment of the suitability of records for inclusion in analysis.

Unlinked records

The 2006-11-16 ACLD file contains all sample records from the 2006 Panel, both those that were linked to a corresponding 2011 and 2016 Census record and those that were not. Records that were linked have information for 2006 and 2011, and most have information for 2016. Records that were not linked have information for 2006 only.

Data items for 2006, 2011 and 2016 have a category labelled: "Unlinked record".

  • the unlinked record category for 2006 data items is empty. It may take on a value in the future once the file is further augmented.
  • the unlinked record category for 2011 data items indicates records from the 2006 Panel sample that were not linked to a corresponding 2011 Census record. These records were not linked to a corresponding 2016 Census record either, i.e., these records have valid information for 2006 but no information for 2011 or 2016.
  • The unlinked record category for 2016 data items indicates records from the 2006 Panel sample that were either:
  1. not linked to a 2011 Census record and therefore not linked to a 2016 Census record, or
  2. linked to a 2011 Census record, but not linked to a corresponding 2016 Census record
Excluding Unlinked Records in TableBuilder

When using the weighted summation option in TableBuilder, no results will be returned for unlinked records, as weights were not applied to these records. Results including unlinked records will only be returned if analysis is performed on unweighted data.

To exclude unlinked records from your analysis, deselect the "Unlinked record" category in each data item before adding it to the table. Such a table would produce a sample count corresponding to the equivalent table run with weights. Refer to the TableBuilder User Guide (cat. no. 1406.0.55.005) for more information on how to select data items for tables.

If the 'unlinked record' category is present on a data item that has already been added to a table, it can be removed by selecting this category within the relevant data item and then pressing the 'Remove from Table' button.

Image: Screen shot from TableBuilder showing an example of deselection of the "unlinked record" category.

Note that removing any category, such as the 'Unlinked record' category, from a table where data has already been generated will clear all data, meaning the table will need to be rerun.

ACLD 2011-2016

Product overview

The 2011-16 ACLD is a representative sample of over 1.2 million records from the 2011 Census (Wave 2) brought together with corresponding records from the 2016 Census (Wave 3). The 2011 Panel includes new births and migrants since the 2006 Census, and is a rich source for exploring how Australian society has changed between the 2011 and 2016 Censuses.

The 2011-16 ACLD product is recommended for analysis of the 2011-16 longitudinal population.

The March 2019 release of the 2011-16 ACLD includes additional data items on the 2011-16 dataset, compared with the 2011-16 dataset released in February 2018.

Note: While the 2011 and 2016 Censuses were predominantly the same, there were some minor differences. For example, a number of changes were made to how industry of employment information was collected for the 2016 Census. The ABS advises this data is not directly comparable to 2011 industry data and should not be used to measure longitudinal transitions. For further information refer to Industry of Employment (INDP) in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

Users are also encouraged to read Understanding the data pages in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0) for information to assist with using and interpreting specific data items across time.

Inquiries

For further information about these and 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.

Data items

Data items list

A complete list of data items included on the ACLD file is provided in an Excel spreadsheet that can be accessed from the Data downloads section.

All data items are created at the person level. This includes data items relating to the family and household of the person selected in the sample. For ease of use, these data items have been divided into Person, Dwelling, Household, Family, Spouse Related, and Male and Female parent related groupings.

Users intending to subscribe to the TableBuilder product or use the microdata product in the DataLab should first refer to the Data Items List to ensure the data they require, and the level of detail required, are available and applicable for the intended use.

For information about the quality of the data items in the ACLD please see the Quality Declaration.

Note: While the 2011 and 2016 Censuses were predominantly the same, there were some minor differences. For example, a number of changes were made to how industry of employment information was collected for the 2016 Census. The ABS advises this data is not directly comparable to 2011 industry data and should not be used to measure longitudinal transitions. For further information refer to Industry of Employment (INDP) in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

New data items

The new data items on the 2011-16 ACLD released in March 2019 are as follows:

New data items
TableBuilder and DataLab
BPFPRCountry of Birth of Mother (2016) 
BPMPRCountry of Birth of Father (2016) 
CTGPChild Type (including grandchildren) (2011, 2016) 
EETPEngagement in Employment, Education and Training (2016) 
EETPFPEngagement in Employment, Education and Training (male parent) (2016) 
EETPFPEngagement in Employment, Education and Training (spouse or partner) (2016) 
EETPFPEngagement in Employment, Education and Training (female parent) (2016) 
FBLFPFamily Blending (2011) 
FMGFGrandparent families (2011, 2016) 
FTPPPForm Type (2016) 
HCFMDHousehold Family Composition (Dwelling) (2011, 2016) 
IEO_URIndex of Economic Resources (2011, 2016) 
IEO_URIndex of Education and Occupation (2011, 2016) 
IFNMFDImputation Flag for Number of Males and Females in Dwelling (2011, 2016) 
IFPOWPImputation Flag for workplace address (2016) 
IRSAD_URIndex of Relative Socio-economic Advantage and Disadvantage (2011, 2016) 
IRSD_URIndex of Relative Socio-economic Disadvantage (2011, 2016) 
LFHRPLabour Force and Hours Worked Not Stated (2011, 2016) 
POWPPlace of Work (2011, 2016) 
RA_URRemoteness Areas (2016) 
RLGPRelationship in Household (including grandchildren) (2011, 2016) 
TISRPNumber of Children Ever Born (ranges) (2011, 2016) 
TYSTAPEducational Institution: Attendee Status (2011, 2016) 

Visitors on Census night

Overseas visitors were excluded from the 2011 ACLD sample. The ACLD, however, does include visitors from within Australia. These are people who were enumerated away from their usual residence on Census Night. Family information cannot be derived for these persons and as such, all family, spouse, and male and female parent related data items are not applicable for visitors.

All dwelling related data items, however, have been made applicable to visitors. This information relates to their dwelling of enumeration on Census Night, not usual residence.

Most household data items are not applicable to visitors, however for four data items, visitors have been included in order to align to standard Census derivations of that data item. These comprise:

  • Total Household Income as stated (weekly) of household in which person was enumerated
  • Total Household Income (weekly) of household in which person was enumerated
  • Household Income Derivation Indicator of household in which person was enumerated
  • Household Composition of household in which person was enumerated.

Any applicable household information for a visitor relates to their place of enumeration, not usual residence.

Where a data item is also applicable to visitors, the usual address indicator data item for the relevant Census year can be used to restrict the table to usual residents only.

The cell comments available in the data item list provide precise information on who is, and is not, applicable for each data item.

Persons temporarily absent on Census night

The Census household form provides the opportunity to list up to three persons who were temporarily absent from the dwelling on Census Night. A limited amount of information is collected for these persons and it is used to better derive the family and household characteristics of the dwelling. In deriving family and household related data items for the ACLD, information on persons temporarily absent was included where relevant and available. Details are provided in cell comments in the data items list.

Not applicable categories

Most data items in the ACLD include a 'not applicable' category. The definition of the 'not applicable' category, where relevant, can be found in the section of the relevant year's Census Dictionary (cat. no. 2901.0), including the previous year releases found on the "Past & Future Releases" list.

Not stated categories

'Not stated' categories occur when no response has been provided for a data item. All Census data items contain 'not stated' categories except for age, sex, marital status and usual address, as this information is imputed for these items.

Other Census products commonly use the symbol '&' to denote a code value of 'not stated'. In the ACLD, the symbol 'X' or '97' has been used. The codes are listed in the data items list.

Quality indicators

The ACLD contains a number of data items that relate to the quality of linkage over the period 2011 to 2016 and have been collectively named Quality Indicators. The first of these are consistency flags. These variables measure the consistency of reporting on linked records between 2011 and 2016. The following consistency flags can be found in the Quality Indicators folder of the TableBuilder data item tree and in the ACLD microdata product available in the DataLab:

  • Age
  • Birthplace of Person
  • Birthplace of Female Parent
  • Birthplace of Male Parent
  • Country of Birth of Spouse or Partner
  • Highest Year of School Completed
  • Hours worked
  • Indigenous Status
  • Level of Highest Non-School Qualification
  • Number of Children Ever Born
  • Registered Marital Status
  • Sex
  • Year of Arrival
Image: Screen shot from TableBuilder showing the Consistency Flags data items under the Quality Indicators folder.

Consistency flags can be used with other variables. For example, age inconsistency can be cross tabulated with sex to examine potential gender differences in the reporting of age.

Screen shot from TableBuilder showing Age Consistency flag cross-tabulated with Sex of person in 2016. The rows show number of people with age consistent within 0 years, 1 year, and so on to 10 or more years, by males, females, and totals in the columns.

In addition to the consistency flags, a "Record linked in 2016 Flag" is also available in the Quality Indicators folder. This flag can be cross tabulated with another data item to examine linkage rates (that is, the proportion of records linked). For example, cross tabulating the record linked flag with State/Territory of usual residence enables an examination of differences in linkage rates between the states and territories.

Image: Screen shot from TableBuilder showing "State/territory of usual residence in 2011" cross-tabulated with "Record linked in 2016" to show linkage rates by State/territory. For example, linkage rate for NSW is 75.93%, Australia total is 75.96%.

File structure

The 2011-16 ACLD datasets in both TableBuilder and DataLab are single-level files that count persons.

In TableBuilder, data items have first been separated by year of collection. For each year, data items are further divided into the following groups:

  • Person - person-level characteristics, covering demographic, culture and language, education, employment and unpaid work topics.
  • Family - derived from the characteristics of the family to which the person belongs on Census Night - e.g., age of youngest child in family.
  • Household - derived from the characteristics of the household to which the person belongs on Census Night - e.g., total weekly household income.
  • Dwelling - derived from the characteristics of the dwelling in which the person was enumerated - e.g., type of dwelling.
  • Female Parent - derived from information about the person's female parent, provided the parent was counted in the same family on Census Night - e.g., labour force status of female parent.
  • Male Parent - derived from information about the person's male parent, provided the parent was counted in the same family on Census Night - e.g., labour force status of male parent.
  • Spouse or Partner - derived from information about the person's spouse/partner, provided the spouse/partner was counted in the same family on Census Night - e.g., highest educational attainment of spouse/partner.
  • Geographical Area - geographic classifications on both a usual residence and place of enumeration basis.

There is also a group of items named Quality Indicators which are consistency flags, imputation flags and movement indicators to assist with the assessment of the suitability of records for inclusion in analysis.

Unlinked records

The 2011-16 ACLD file contains all sample records from the 2011 Panel, both those that were linked to a corresponding 2016 Census record and those that were not. Records that were linked have information for 2011 and 2016. Records that were not linked have information for 2011 only.

Data items for both 2011 and 2016 have a category labelled: "Unlinked record".

  • the unlinked record category for 2011 data items is empty. It may take on a value in the future once the file is further augmented.
  • the unlinked record category for 2016 data items indicates records from the 2011 Panel sample that were not linked to a corresponding 2016 Census record, i.e., these records have valid information for 2011 but no information for 2016.
Excluding Unlinked Records in TableBuilder

When using the weighted summation option in TableBuilder, no results will be returned for unlinked records in 2016, as weights were not applied to these records. Results including unlinked 2011 records will only be returned if analysis is performed on unweighted data.

To exclude unlinked records from your analysis, deselect the "Unlinked record" category in each data item before adding it to the table. Such a table would produce a sample count corresponding to the equivalent table run with weights. Refer to the TableBuilder User Guide (cat. no. 1406.0.55.005) for more information on how to select data items for tables.

If the 'unlinked record' category is present on a data item that has already been added to a table, it can be removed by selecting this category within the relevant data item and then pressing the 'Remove from Table' button.

Image: Screen shot from TableBuilder showing an example of deselection of the "unlinked record" category.

Note that removing any category, such as the 'Unlinked record' category, from a table where data has already been generated will clear all data, meaning the table will need to be rerun.

ACLD 2006-2011

Product overview

The 2006-11 ACLD is a representative sample of almost one million records from the 2006 Census (Wave 1) brought together with corresponding records from the 2011 Census (Wave 2).

This dataset was released in 2013, and updated with additional variables in 2016, including three Visa data items from the Department of Social Services’ Settlement Database. It is a rich source for exploring how Australian society has changed between the 2006 and 2011 Censuses.

The original 2006-11 ACLD product has been included for reference. It is recommended for analysis dependent on visa class information.

Inquiries

For further information about these and 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.

Data items

Data items list

A complete list of data items included on the ACLD file is provided in an Excel spreadsheet that can be accessed from the Data downloads section. The population applicable to each data item is described in the cell comments in this spreadsheet.

All data items are created at the person level. This includes data items relating to the family and household of the person selected in the sample. For ease of use, these data items have been divided into Person, Dwelling, Household, Family, Spouse Related, and Male and Female parent related groupings.

Users intending to purchase the TableBuilder product should first refer to the Data Items List to ensure the data they require, and the level of detail required, are available and applicable for the intended use.

Visitors on Census night

Overseas visitors were excluded from the 2006 ACLD sample. The ACLD, however, does include visitors from within Australia. These are people who were enumerated away from their usual residence on Census Night. Family information cannot be derived for these persons and as such all family, spouse, and male and female parent related data items are not applicable for visitors.

All dwelling related data items, however, have been made applicable to visitors. This information relates to their dwelling of enumeration on Census Night, not usual residence.

Most household data items are not applicable to visitors, however for four data items, visitors have been included in order to align to standard Census derivations of that data item. These comprise:

  • Total Household Income as stated (weekly) of household in which person was enumerated
  • Total Household Income (weekly) of household in which person was enumerated
  • Household Income Derivation Indicator of household in which person was enumerated
  • Household Composition of household in which person was enumerated.

Any applicable household information for a visitor relates to their place of enumeration, not usual residence.

Where a data item is applicable to visitors, the Usual Address Indicator on Census Night data item for the relevant Census year can be used to restrict the table to usual residents only.

The cell comments available in the data item list provide precise information on who is, and is not, applicable for each data item.

Persons temporarily absent on Census night

The Census household form provides the opportunity to list up to three persons who were temporarily absent from the dwelling on Census Night. A limited amount of information is collected for these persons and it is used to better derive the family and household characteristics of the dwelling. In deriving family and household related data items for the ACLD, information on persons temporarily absent was included where relevant and available. Details are provided in cell comments in the data items list.

Non applicable categories

Most data items in the ACLD include a 'Not applicable' category. The definition of the 'Not applicable' category, where relevant, is explained in cell comments for each data item in the data item list.

Not stated categories

'Not stated' categories occur when no response has been provided for a data item. All Census data items contain not stated categories except for age, sex, marital status and usual address, as this information is imputed for these items.

Other Census products commonly use the symbol '&' to denote a code value of Not Stated. In the ACLD the symbol 'x' or ‘97’ has been used. The codes are listed in the data items list

Longitudinal data items

The ACLD contains a small number of data items that relate to the linkage over the period 2006 to 2011 and have been collectively named longitudinal data items. The first of these are consistency flags. These variables measure the consistency of reporting on linked records between 2006 and 2011. The following consistency flags can be found in the Longitudinal folder of the TableBuilder data item tree and in the ACLD microdata product in the DataLab:

  • Age
  • Birthplace of Person
  • Birthplace of Male Parent
  • Birthplace of Female Parent
  • Sex
  • Year of Arrival
  • Number of Children Ever Born
  • Registered Marital Status
  • Highest Year of School Completed
  • Level of Highest Non-School Qualification
  • Country of Birth of Spouse or Partner
  • Age of Spouse or Partner
  • Indigenous Status
Image: Screen shot from TableBuilder showing Consistency flags can be found in the Longitudinal Folder.

Consistency flags can be used with other variables. For example, age inconsistency can be cross tabulated with Sex to examine potential gender differences in the reporting of age.

Screen shot from TableBuilder showing Age Consistency flag cross-tabulated with Sex of person in 2011. The rows show number of people with age consistent within 0 years, 1 year, and so on to 10 or more years, by males, females, and totals in the columns.

In addition to the consistency flags, a Record linked from 2006 flag is also available in the Longitudinal folder. This flag can be cross tabulated with another data item to examine linkage rates (that is, the proportion of records linked). For example, cross tabulating the Record linked flag with State/Territory of usual residence enables an examination of differences in linkage rates between the states and territories.

Image: Screen shot from TableBuilder showing "State/territory of usual residence in 2006" cross-tabulated with "Record linked in 2011" to show linkage rates by State/territory. For example, linkage rate for NSW is 81.50%, Australia total is 81.74%.

File structure

The 2006-11 ACLD product in both TableBuilder and DataLab is a single-level file that counts persons and has data items for 2006 and 2011.

In TableBuilder, data items have first been separated by year of collection. For each year, data items are further divided into the following groups:

  • Person - person-level characteristics, covering demographic, culture and language, education, employment and unpaid work topics.
  • Female Parent - derived from information about the person's female parent provided the parent was counted in the same family on Census Night., e.g. labour force status of female parent.
  • Male Parent - derived from information about the person's male parent provided the parent was counted in the same family on Census Night, e.g. labour force status of male parent.
  • Spouse or Partner - derived from information about the person's spouse/partner, provided the spouse/partner was counted in the same family on Census Night, e.g. highest educational attainment of spouse/partner.
  • Family Related - derived from the characteristics of the family in which the person lives, provided the person was counted at home on Census Night - e.g age of youngest child in family.
  • Household Related - derived from the characteristics of the household in which the person lives, provided the person was counted at home on Census Night - e.g. total weekly household income.
  • Dwelling Related - derived from the characteristics of the dwelling in which the person was enumerated - e.g. type of dwelling.
  • Geographical Area - geographic classifications on both a usual residence and place of enumeration basis.

Unlinked records

The ACLD file in TableBuilder contains all sample records from the 2006 Panel, both those that were linked to a corresponding 2011 Census record and those that were not. Records that were linked have information for 2006 and 2011. Records that were not linked have information for 2006 only.

Data items for both 2006 and 2011 have a category labelled: unlinked record.

  • the unlinked record category for 2006 data items is empty. It may take on a value in the future once the file is further augmented.
  • the unlinked record category for 2011 data items indicates records from the 2006 Panel sample that were not linked to a corresponding 2011 Census record, i.e., these records have valid information for 2006 but no information for 2011.
Excluding Unlinked Records

When using the weighted summation option in TableBuilder, no results will be returned for unlinked records in 2011 as weights were not applied to these records. Results will be returned if analysis is performed on unweighted data only. If desired, this category can be excluded from tables by ensuring that the 'unlinked record' category is deselected before each data item is added to the table. Such a table would produce a sample count corresponding to the equivalent table run with weights. Refer to the TableBuilder User Guide for more information on how to select data items for tables.

Image: Screenshot from TableBuilder showing how to uncheck the 'Unlinked record' box to exclude unlinked records.

If the 'unlinked record' category is present on a data item that has already been added to a table, it can be removed by selecting this category within the relevant data item and then pressing the 'Remove from Table' button.

Image: Screenshot from TableBuilder showing unlinked records can be removed by checking the Unlinked record box and clicking on the "remove from table" button

Note that removing any category, such as the 'unlinked record' category, from a table where data has already been generated will clear all data, meaning the table will need to be rerun.

Data consistency

Analysing the ACLD - Understanding consistency between waves

The ACLD is a longitudinal dataset using data from successive Censuses.

While the Censuses had predominantly the same questions and were processed in a similar way, there were some differences between them.

Users are encouraged to read Understanding the data pages in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0), information in How Australia Takes a Census, 2011 (cat. no. 2903.0), and the 2006 Census data quality page for information to assist with using and interpreting specific data items across time.

For example, a number of changes were made to how industry of employment information was collected for the 2016 Census. The ABS advises this data is not directly comparable to the previous Census Industry of employment data, and should not be used to measure longitudinal transitions between industries from 2011 to 2016. For further information refer to Industry of Employment (INDP) in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

Other data items that are different between Census years are personal, family and household income. Income was collected in ranges and these ranges are different in different Census years. The ACLD does not include an adjustment to income data for inflation.

A small percentage of linked records have inconsistent data, such as a different country of birth at the two time points or an age inconsistency of more than one year. Inconsistencies may be due to: 

  • false link - the record pair does not belong to the same individual
  • reporting error - information for the same individual was reported differently in 2006, 2011 and in 2016
  • processing error - the value of a data item was inaccurately assigned or imputed during processing.

In most analysis, the effect of inconsistent information has a very small impact. Characteristics from either the 2006, 2011 or 2016 data can be used in tables and some exploration of consistency over time will assist in drawing appropriate conclusions.

For further information about the ACLD linkage methodology refer to Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016 (cat. no. 2080.5).

ACLD microdata contains a large number of data items and in some cases the level of detail has been collapsed from that described in the Census Dictionary. For more information on the level of detail provided, please see the associated Data Items list in the Data downloads section.

Using the ACLD in DataLab

The DataLab is an interactive data analysis solution available for high end users to run advanced multivariate statistical analyses, for example, multiple regressions and structural equation modelling. The DataLab environment contains up-to-date versions of SPSS, Stata, SAS and R analytical languages. Controls in the DataLab have been put in place to protect the identification of individuals and organisations. These controls include environmental protections, data de-identification and confidentialisation, access safe guards and output clearance. All output from DataLab sessions is cleared by an ABS officer before it is released.

For more information about the DataLab please see About the DataLab. To apply for access to the ACLD in the DataLab, please contact Microdata Access Strategies via microdata.access@abs.gov.au.

For information about accessing the ACLD test file for DataLab, please see ABS DataLab ACLD Test File section.

To access the ACLD via the ABS DataLab, please register or log in, via the Microdata Entry Page. Please familiarise yourself with the Responsible Use of ABS Microdata Guide (cat. no. 1406.0.55.003), if you intend to access ACLD microdata.

DataLab test file

ABS DataLab ACLD test files

Note: The test files do not contain real data and cannot be used for analysis.

Test files have been created for the ACLD microdata products, and are consistent with the structure outlined in File Structure. The purpose of the test files is to allow researchers/analysts to become familiar with the data structure and prepare code/programs prior to applying for, or commencing, a DataLab session. This aims to maximise the value of sessions by saving users' time and resources once they enter the DataLab environment.

The test file mimics the structure of the ACLD microdata datasets - it has the same data items and allowed values, however, all data in the test file is false, created through a randomisation process. Proportions of values within data items in the test file will be similar to those in the real data; however, relationships between data items are not (intentionally) maintained. It is extremely unlikely that a record in the test file would match with a genuine record in the real data.

The test files are available as a free download from the Data downloads section. They can also be made available in other file formats on request, if required. For further information users should email microdata.access@abs.gov.au.

Using the ACLD in TableBuilder

TableBuilder user guide

The TableBuilder User Guide (cat. no. 1406.0.55.005) is a comprehensive reference guide for the web interface of TableBuilder. It includes information on building and working with tables, customising data, understanding the results, data visualisation options, and confidentiality processes.

Counting units and weights

Weighting is the process of adjusting results from a sample to infer results for the total population. To do this, a weight is allocated to each person. The weight is the value that indicates how many population units are represented by the sample unit.

Both the sample and weighted count options have been made available for the ACLD. It is therefore critical that weighted or unweighted counts are selected as appropriate when specifying tables. The following image shows the available Summation Options.

Image: Screen shot from TableBuilder showing Summation Options.

The default option used for the ACLD is weighted count. Weights should be used when making inferences about the longitudinal Australian population and will be the basis for most analyses. Uses for unweighted counts are generally limited to research into unlinked records and more sophisticated analysis for those seeking to understand the weighting methodology better or wishing to apply their own weighting methods.

Relative standard error

While weighted counts are available in the ACLD TableBuilder, the Relative Standard Error will not be calculated for these counts due to the confounding effects of linking error present in the sample, which were not able to be quantified.

Confidentiality features in TableBuilder

In accordance with the Census and Statistics Act 1905, all the data in TableBuilder are subjected to a confidentiality process before release. This confidentiality process is undertaken to avoid releasing information that may allow the identification of particular individuals, families, households, dwellings or businesses.

Processes used in TableBuilder to confidentialise records include the following: 

  • perturbation of data
  • table suppression.

Perturbation of data

To minimise the risk of identifying individuals in aggregate statistics, a technique is used to randomly adjust cell values. This technique is called perturbation. Perturbation involves small random adjustments of the statistics and is considered the most satisfactory technique for avoiding the release of identifiable statistics while maximising the range of information that can be released. These adjustments have a negligible impact on the underlying pattern of the statistics.

The introduction of these random adjustments result in tables not adding up. Randomly adjusted individual cells will be consistent across tables, but the totals in any table may not be the sum of the individual cell values. The size of the difference between summed cells and the relevant total will generally be very small, as demonstrated below.

Image: Example of Perturbed and Unperturbed total counts in TableBuilder

(Sum of cells = 450,054 + 477,460 = 927,514. Difference of 6 relative to displayed total.)

Table suppression

Some tables generated within TableBuilder may contain a substantial proportion of very low counts within cells (excluding cells that have counts of zero). When this occurs, all values within the table are suppressed in order to preserve confidentiality. The following error message displayed at the bottom of the table indicates when table suppression has occurred.

'ERROR: The table has been suppressed as it is too sparse'.

Access to TableBuilder

To access the ACLD via TableBuilder, please register or log in, via the Microdata Entry Page. Please familiarise yourself with the Responsible Use of ABS Microdata Guide (cat. no. 1406.0.55.003), if you intend to access ACLD microdata.

Data downloads

Data files

History of changes

Show all

18/09/2019 

DataLab file updated: 

  • 'Type of Internet connection 2016' was updated to 'Dwelling Internet connection 2016' variable name, and category labels updated.

TableBuilder updated:

  • 'Type of Internet connection 2016' was updated to 'Dwelling Internet connection 2016' variable name, and category labels updated.

Data Item Lists updated:

  • 'Type of Internet connection 2016' was updated to 'Dwelling Internet connection 2016' variable name, and category labels updated.
  • Minor typo and formatting improvements.
20/03/2019 

Information added relating to the 2006-11-16 linkage

20/03/2019 

Formatting changes to combine the two separate publications, Microdata: Australian Census Longitudinal Dataset, 2006-2011 and Microdata: Australian Census Longitudinal Dataset, 2011-2016, into one publication.

24/10/2018

TableBuilder updated:

  • 'Equivalised Total Household Income (weekly) of household in which person was enumerated in 2016' corrected and replaced
  • 'Age Consistency Flag 2011-2016' corrected and replaced
  • 'Indigenous Status Consistency Flag 2011-2016' corrected and replaced
  • Continuous data items added
30/08/2018

DataLab file updated:

  • 'Age Consistency Flag 2011-2016' corrected and replaced
  • 'Indigenous Status Consistency Flag 2011-2016' corrected and replaced
29/05/2018

DataLab file updated:

  • 'Equivalised Total Household Income (weekly) of household in which person was enumerated in 2016' corrected and replaced
29/03/2018

Minor formatting improvements to Data Item Lists.

06/03/2018

Minor formatting improvements and fixes to links. No changes to data.

22/03/2016

An ACLD test file has been included, to assist ABS Data Laboratory users.

This test file will allow users to generate and test code prior to commencing a session in the ABS Data Laboratory. For more information, please see the ABS Data Laboratory Test File page.

12/02/2016

The ACLD has been re-released in both TableBuilder and the on-site ABS Data Laboratory with a number of enhancements.

In TableBuilder

  • three data items (Visa Type, Location of Visa Application, and Applicant Status) added from the Settlement Database that were made available in the Australian Census Migrants Integrated Dataset (ACMID) TableBuilder file;
  • additional Census variables, such as Socio-Economic Indexes for Areas (SEIFA) and dwelling location;
  • more finely disaggregated data items, for example, year of arrival in Australia in single years and religious affiliation at the three digit level;
  • refinements to the consistency flags; and
  • a revised weight (replacing the original weight) to better account for net overseas migration between the 2006 and 2011 Census Nights. Users who have analysed the ACLD prior to 12 February 2016 may notice changes to estimates produced with the revised weight. Estimates of population groups will be different with the total weighted population estimate being 19.5 million compared to 18.6 million on the old weight. Proportions are expected to only show small differences when previous tables are compared.

In the ABS Data Laboratory

  • variable names changed to be more intuitive;
  • refinements to the consistency flags; and
  • a revised weight (replacing the original weight) to better account for net overseas migration between the 2006 and 2011 Census Nights.
03/12/2015

The ACLD file available for use through the on-site ABS Data Laboratory has been updated.

This updated version includes three new data items relating to migrants that have been made available via the Settlement Database from the Department of Social Services.
An update of the ACLD TableBuilder file and the ACLD ABS Data Laboratory file is planned for the near future.

02/07/2015

The ACLD is now available as a unit record file that can be accessed through the on-site ABS Data Laboratory network in ABS offices throughout Australia.

For further information please contact microdata.access@abs.gov.au

This new ACLD Microdata Product features some revisions to the original dataset released in TableBuilder in December 2013:

  • categories of several data items have been expanded to match the level of disaggregation available in Census TableBuilder
  • additional Census data items (including Socio-Economic Indexes for Areas) have been added
  • weights have been revised to take better account of migration between 2006 and 2011

To maintain consistency it is planned to release these updates to the ACLD TableBuilder file in the near future.

Glossary

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Terms and definitions applicable to the ACLD can be located via the Census Dictionary Glossary. Additional information on data items is also available in the associated cell comment within the Data Items list. This is available via the Data downloads section.

Quality declaration

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, see ABS Institutional Environment.

In April 2012, the ABS became an accredited Integrating Authority under the Commonwealth data integration interim arrangements. A copy of the accreditation claims made by the ABS, which have been verified by an independent auditor, is available on data.gov.au. The ABS only undertakes data integration for statistical and research purposes and where there is a strong public benefit in doing so.

The Australian Census Longitudinal Dataset (ACLD) is released in TableBuilder and as a microdata product in the DataLab. Microdata files are released in accordance with the conditions specified in the Statistics Determination section of the Census and Statistics Act 1905. This ensures that confidentiality is maintained whilst enabling micro level data to be released. More information on the confidentiality practices associated with TableBuilder can be found in TableBuilder, User Guide (cat. no. 1406.0.55.005) on the Confidentiality page. To protect confidentiality of data within the DataLab, users are supervised at all times and must not bring mobile phones, cameras, USB keys, laptops, palm pilots or similar transmission or storage devices into the secure location. All outputs produced by users in DataLab are manually cleared for release after the session.

Relevance

Data for the Census of Population and Housing used in this product were collected on 8 August 2006, 9 August 2011 and 9 August 2016. The scope of the Census is all persons enumerated in Australia on Census night. The Census covers all areas in Australia and includes persons living in both private and non-private dwellings but excludes: 

  • diplomatic personnel of overseas governments and their families
  • Australian residents overseas on Census Night and

The ACLD is built upon a 5% sample of records taken from a particular Census that is then linked to following Censuses. There are currently two samples, 2006 and 2011, with each being representative of the Australian population at the time of the Census collection.

Overseas visitors are excluded from the 2006 and 2011 ACLD Panel samples. Visitors within Australia to private and non-private dwellings on Census Night are included.

The Census collects information on demographics, income, labour force, unpaid work, dwelling characteristics and family and household relationships.

For more information, see How Australia Takes a Census, 2006 (cat. no. 2903.0), How Australia Takes a Census, 2011 (cat. no. 2903.0), Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0), and the 2006, 2011 and 2016 issues of the Census Dictionary (cat. no. 2901.0).

Timeliness

The Census of Population and Housing is conducted every five years. For further information see the publications How Australia Takes a Census, 2006 (cat. no. 2903.0), How Australia Takes a Census, 2011 (cat. no. 2903.0) and Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

The first wave of Census data for the ACLD was from 2006, the second wave was from 2011, and the third wave was from 2016.

Microdata from the 2006-11 ACLD was first made available in December 2013. The 2011-16 data was available from February 2018, and the 2006-11-16 data available from March 2019.

Accuracy

The ACLD is a random 5% sample of persons enumerated in Australia on either Census Night, 2006 or Census Night, 2011 which has been linked using statistical techniques to records from successive Censuses. False links can occur during the linkage process as even when a record pair matches on all or most linking fields, it may not actually belong to the same individual. The nature of the process used for the ACLD linkage means that while the methodology is designed to ensure links obtained are to a high degree of accuracy, some false links may be present within the ACLD dataset. There is an estimated 5-10% false link rate in the original linkage of the 2006-2011 ACLD, an estimated 5% false link rate in the re-link of the 2006-2011 ACLD and an estimated 1% false link rate in the 2011-2016 linkages.

Sampling error occurs because only a small proportion of the total population is used to produce estimates that represent the whole population. Sampling error refers to the fact that for a given sample size, each sample will produce different results, which will usually not be equal to the population value. There are two common ways of reducing sampling error - increasing sample size and/or utilising an appropriate selection method (for example, multi-stage sampling would be appropriate for household surveys). Given the large sample size for the ACLD (1 in 20 persons), and simple random selection, sampling error is minimal.

The ACLD sample was weighted to an estimate of the population that was resident in Australia on Census Night for the relevant linkage periods. For example, the linkage of the 2011 Panel to the 2016 Census is weighted to an estimate of the population that was resident in Australia at both the 2011 and 2016 Censuses. The weights adjust for missed links and Census undercount.

Information on methodology, linkage quality and weighting can be found in Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016 (cat. no. 2080.5). Steps are taken to confidentialise the data made available on TableBuilder in such a way as to maximise the usefulness of the content while maintaining the confidentiality of respondents selected in the ACLD sample. As a result it may not be possible to exactly reconcile all the statistics produced from the microdata with other published statistics. Further information about the steps taken to confidentialise the microdata can be found in TableBuilder, User Guide (cat. no. 1406.0.55.005) on the Confidentiality page.

Coherence

A small percentage of linked records have inconsistent data, such as a different country of birth at the two time points or an age inconsistency of more than one year. Inconsistencies may be due to:

  • false link - the record pair does not belong to the same individual
  • reporting error - information for the same individual was reported differently in 2011 and in 2016
  • processing error - the value of a data item was inaccurately assigned or imputed during processing.

ACLD microdata contains a large number of data items and in some cases the level of detail has been collapsed from that described in the Census Dictionary. For more information on the level of detail provided, please see the associated Data Items list.

While the 2011 and 2016 Censuses had predominantly the same questions and were processed in a similar way, there were some differences between them.

For example, a number of changes were made to how industry of employment information was collected for the 2016 Census. The ABS advises this data is not directly comparable to the previous Census Industry of employment data, and should not be used to measure longitudinal transitions between industries from 2011 to 2016. For further information refer to Industry of Employment (INDP) in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

Notable data items that are different between Census years are personal, family and household income. Income was collected in ranges and these ranges are different in different Census years. The ACLD does not include an adjustment to income data for inflation.

Some data items were derived differently between Censuses. In these instances, to aid comparability, the 2006 and 2011 variables were re-derived to make them consistent with the 2016 derivation.

For more information on the differences between the 2006, 2011 and 2016 Censuses see What's New for 2011? and What's New for 2016?

Estimates derived from the ACLD may differ to those derived from other sources. This is due to a range of factors including:

  • Collection methodology - The ACLD is derived from Census data that is self-reported by households across Australia on Census night. This will differ from other ABS collections which may rely on different collection methodologies (e.g. trained interviewers, administrative sources). In addition, the way survey questions are phrased and the answer options available for a given question may affect the information provided by respondents.
  • Reference period - The reference periods for the ACLD are the Census nights of each year. Other collections may use different reference periods.
  • Sampling design - The ACLD uses a 5% sample of Census data as its base population. This will differ from other collections that may collect information from the entire population of Australia (e.g. the Census) or from a sample of dwellings (e.g. Labour Force Survey).
  • Sampling and non-sampling error - While every effort is made to minimise error, each collection will have some level of error. Survey collections are subject to some level of sampling error, as they are based on information obtained from a sample of dwellings or businesses. The Census is not subject to this type of error, but is subject to some level of undercount. The ACLD is constructed using a sample of records from the Census, and is therefore subject to a level of sampling error of its own.
  • Scope and coverage - The ACLD weights benchmark the linked records to the longitudinal population that was in scope of both or all three Censuses. This will be different to cross-sectional estimates which may be benchmarked to a point-in-time population, such as the Estimated Resident Population.
  • Linkage error - The ACLD is subject to linkage error, as records from one Census are linked to corresponding records from the subsequent Census. While every effort is made to minimise false links, they can occur. Linkage error will not be apparent in other collections which are not produced through data integration.

For these reasons, while the results from the ACLD are considered to be broadly representative of the Australian population, they are not strictly comparable with statistics derived from other collections.

For detailed information about the different methodologies for each collection, refer to the Explanatory Notes within each release.

For detailed information regarding the differences between the Census and Labour Force collections, refer to The 2016 Census and the Labour Force Survey in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

For detailed information regarding Census data, including changes to Census questions and data quality statements for each Census data item, refer to Understanding the data in Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 (cat. no. 2900.0).

Interpretability

This publication should be referred to when using the microdata. It contains information on the Methodology, File Structure, Using the ACLD in TableBuilder, The ACLD in the DataLab, Conditions of Use and the Data Items list.

Detailed information on methodology, linkage quality and weighting can be found in Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016 (cat. no. 2080.5). The ABS publishes extensive information on Census Data Quality.

Accessibility

The Australian Census Longitudinal Datasets, 2006-11, 2011-16 and 2006-11-16 can be accessed through TableBuilder and the DataLab.

These microdata products are available to approved users. Users wishing to access the microdata should read the How to apply for Microdata web page, before applying for access by emailing microdata.access@abs.gov.au. Users should also familiarise themselves with information available via the Microdata Entry Page.

Any questions regarding access to microdata can be forwarded to microdata.access@abs.gov.au or phone (02) 6252 7714.

Abbreviations

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ABSAustralian Bureau of Statistics
DATALABData Laboratory
ACLDAustralian Census Longitudinal Dataset 
ACMIDAustralian Census Migrants Integrated Dataset
ASGSAustralian Statistical Geography Standard 
CURFConfidentialised Unit Record File
ERPEstimated Resident Population
SA2Statistical Area 2

Previous catalogue number

This release previously used catalogue number 2080.0.