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 is the most comprehensive snapshot of the country and tells the story of how we are changing. Census data tells us about the economic, social and cultural make-up of the country. 

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.

Four waves of data have so far contributed to the ACLD from the 2006 Census (wave 1), 2011 Census (wave 2), 2016 Census (wave 3) and 2021 Census (wave 4).

There are three ACLD panels, representing a 5% sample of records from the 2006, 2011 and 2016 Censuses. There are seven ACLD datasets which have been generated that initiate from one of these panels.

Available ACLD datasets
PanelDataset NameDataset Description
2006 panelAustralian Census Longitudinal Dataset, 2006-2011Contains the original 2006-2011 linkage with additional experimental social security and related variables.
Australian Census Longitudinal Dataset, 2006-2011 (with visa variables)Contains the original 2006-2011 linkage with three additional visa variables from the Department of Social Services' Settlement Database.
Australian Census Longitudinal Dataset, 2006-2011-2016Contains a 2006-2011-2016 linkage, including an updated 2006-2011 linkage to take advantage of an improved linkage methodology since the initial release.
Australian Census Longitudinal Dataset, 2006-2011-2016-2021Contains a 2006-2011-2016-2021 linkage, including an updated 2006-2011 linkage to take advantage of an improved linkage methodology since the initial release.
2011 panelAustralian Census Longitudinal Dataset, 2011-2016Contains a 2011-2016 linkage.
Australian Census Longitudinal Dataset, 2011-2016-2021Contains a 2011-2016-2021 linkage.
2016 panelAustralian Census Longitudinal Dataset, 2016-2021Contains a 2016-2021 linkage.

 

This publication provides information about longitudinal microdata from the Census made available via different methods for analytical research. Microdata products contain the most detailed information available from the Census. They contain data which is either the response to individual questions on the Census form or derived from answers to two or more questions. 

This publication includes information on: 

  • the microdata products available 
  • the methodology 
  • the quality of the microdata 
  • how to apply for and use the microdata. 

Privacy

The ABS is given the authority to collect, hold and use personal information for Census and statistical purposes as legislated by the Australian Bureau of Statistics Act 1975 and the Census and Statistics Act 1905. Data are released under the Census and Statistics Act 1905, which has provision for the release of individual level records (unit records) where the information is not likely to enable the identification of a particular person or organisation. Census microdata products do not contain names or addresses, and each have different assessment processes conducted and measures applied to ensure they are sufficiently confidentialised.  

Available products

Detailed microdata: allows in-depth analysis of detailed microdata within the ABS' secure DataLab environment. The ACLD datasets available in the DataLab are:

  • Australian Census Longitudinal Dataset, 2006-2011 (with visa variables)
  • Australian Census Longitudinal Dataset, 2006-2011-2016-2021
  • Australian Census Longitudinal Dataset, 2011-2016-2021
  • Australian Census Longitudinal Dataset, 2016-2021

TableBuilder: allows users to build tables based on underlying microdata. The ACLD datasets available in TableBuilder are:

  • Australian Census Longitudinal Dataset, 2006-2011 (with visa variables)
  • Australian Census Longitudinal Dataset, 2006-2011 (with experimental social security and related variables)
  • Australian Census Longitudinal Dataset, 2006-2011-2016
  • Australian Census Longitudinal Dataset, 2011-2016

The 2021 Census data (wave 4) will be added to the ACLD TableBuilder datasets in early-mid 2024.

Applying for access

Before applying for access, users should read the Responsible use of ABS microdata user guide to understand the obligations when using microdata. Additionally, TableBuilder users should read and familiarise themselves with the information contained in the TableBuilder User Guide.

The list of variables (also referred to as data items) included in each of the ACLD datasets is available for download under Data downloads.

To apply, see the TableBuilder and DataLab pages.

Data available on request

Data obtained in the Census but not contained in a Census data product may be available from the ABS, on request, as statistics in tabulated form. Subject to confidentiality and sampling variability constraints, special tabulations can be produced incorporating variables, populations and geographic areas selected to meet individual requirements. These are available on a fee for service basis.  

Enquiries should be submitted via an Information consultancy form.  

To view variables available for request, refer to either the current  2021 Census dictionary or the historical dictionaries from previous Census years. 

Further information

Further information about the ACLD can be found on the ACLD page.

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

Methodology

Scope and coverage

The ACLD is a random 5% sample panel of people enumerated in Australia on each Census Night. The sample panels are linked to subsequent Censuses using statistical techniques. Four waves of data have contributed to the ACLD so far, from the 2006 (wave 1), 2011 (wave 2), 2016 (wave 3) and 2021 (wave 4) Censuses.

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

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

Visitors

Overseas visitors were excluded from the ACLD samples.  

The ACLD does include visitors to a household. These are people who were enumerated in a household they do not usually live in. Family information cannot be derived for these people and as such, all family, spouse, and male and female parent related variables are not applicable for these individuals. 

All dwelling related variables have been made applicable for visitors to a household. This information relates to their dwelling of enumeration on Census Night, not their usual residence. 

Most household variables are not applicable for visitors to a household, however for four variables, visitors have been included in order to align to standard Census derivations of that variable. 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 to a household relates to their place of enumeration, not usual residence. 

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

For further information on place of enumeration and place of usual residence see, Comparing Place of enumeration with Place of usual residence.

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

Persons temporarily absent on Census Night

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

Further information 

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

Sample design

Multi-panel sample method

The ACLD sample is maintained through the application of a multi-panel framework. This 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 dataset containing one panel of records representing a single Census population (i.e. 2006 or 2011 or 2016). 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 each panel to account for new births, migrants and missed links in previous panels. This means that new births or migrants from 2007 would not have been added to the Australian Census Longitudinal Dataset, 2006-2011-2016-2021 dataset, however, they may have been selected in the 2011 panel and therefore included in the Australian Census Longitudinal Dataset, 2011-2016-2021 dataset. This allows flexibility for users to 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

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 2006 panel sample was 4.9%, this achieved a linked sample size of 3.8% of the population after missed links and people no longer being in scope due to death or overseas migration. The 2006 panel sample of 979,662 records from the 2006 Census was linked to the 2011 Census, resulting in a linked sample size of 756,945 at a linkage rate of 77.3%. From the 2006 panel sample 605,618 records linked to both the 2011 and 2016 Censuses, and 501,941 records linked to the three (2011, 2016 and 2021) Censuses. 

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. The 2011 panel sample of over one million records (1,221,059) from the 2011 Census was linked to the 2016 Census, resulting in a linked sample size of 927,517 records at a linkage rate of 76.0%. This achieved a linked sample size of 4.3%. From the 2011 panel sample 814,337 records linked to both the 2016 and 2021 Censuses. 

The 2016 panel sample was 5.6%, this achieved a linked sample size of 4.7% of the population after allowing for missed links and people no longer being in scope. The 2016 panel sample of 1,308,274 records from the 2016 Census was linked to the 2021 Census, resulting in a linked sample size of 1,088,307 records at a linkage rate of 83.2%. This achieved a linked sample size of 4.7%. 

In each case the linkage sample size decrease was due to missed links and people no longer being in scope due to death or overseas migration.

ACLD multi-panel linkage

The 2006 panel sample is 4.9% (979,662 person records), this achieved a linked sample size of 3.8% to 2011 records. 77.3% (756,945 person records) from the 2006 panel sample was linked to 2011 records. From the 2006 panel sample 61.8% (605,618 person records) linked to both the 2011 and 2016 Censuses, this is 3.1% of the 2006 population. 51.2% (501,941 person records) linked to the three (2011, 2016 and 2021) Censuses, this is 2.5% of the 2006 population. 

The 2011 panel sample is 5.7% (1,221,059 person records), this achieved a linked sample size of 4.3% to 2016 records. 76.0% (927,517 person records) from the 2011 panel sample was linked to 2016 records. From the 2011 panel sample 66.7% (814,337 person records) linked to both the 2011 and 2021 Censuses, this is 3.8% of the 2011 population.

The 2016 panel sample is 5.6% (1,308,274 person records), this achieved a linked sample size of 4.7% to 2021 records. 83.2% (1,088,307 person records) from the 2016 panel sample was linked to 2021 records, this is 4.7% of the 2016 population.

696,356 person records overlapped between the 2006 and 2011 panel samples. 817,915 person records overlapped between 2011 and 2016 panel samples.

Linking methodology

The ACLD products in this release have been produced by making use of the following linkages: 

  • 2006 Census ACLD sample to 2011 Census
  • 2011 Census ACLD sample to 2016 Census
  • 2006-2011 ACLD sample to 2016 Census
  • 2016 Census to June 2019 Person Linkage Spine 
  • 2021 Census to June 2022 Person Linkage Spine 
ACLD sample linkages

ACLD sample linkages between each Census year were undertaken using a mix of deterministic and probabilistic linkage methodologies. 

Deterministic linkage methodology uses pre-defined rules to find unique matches between datasets. Matching rules may be gradually broadened to tolerate differences between datasets. 

Probabilistic linkage methodology allows for links to be assigned despite missing or incomplete data, provided there is enough agreement between linkage variables to offset any disagreement. Probabilistic linkage produces as a linkage weight, which is a numerical measure that shows how well records match. 

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

  • 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. 
  • The person had no record in the later Census. 
Census to ABS Person Spine linkages

The 2016 and 2021 Censuses were both linked to the ABS Person Linkage Spine, which is the linkage infrastructure that underpins the Person-Level Integrated Data Asset (PLIDA).  

The Spine aims to cover all people who were resident in Australia for the given reference period. It is updated annually, using the following administrative datasets:  

  • Medicare Consumer Directory
  • DOMINO Centrelink Administrative Data
  • Personal Income Tax Client Register. 

For further information about the Spine see Person linkage spine

For the 2016 Census, 93.68% of records linked to the June 2019 Spine. For the 2021 Census, 96.26% of records linked to the June 2022 Spine. 

There are two main reasons why some records were not linked to the Spine: 

  • Records belonging to the same individual were present on both the Spine and the Census, but they contained missing or inconsistent information. It should be noted that the Spine contains longitudinal linkage data to mitigate this issue. 
  • The individual who completed the Census was not present on the Spine. The Spine aims to cover all persons who are resident in Australia for a given reference period, but it does not have perfect population coverage.

Linkage results

The following tables display the linkage rate for a range of sub-populations across the different ACLD datasets. The linkage results for the original 2006-2011 panel can be found in the Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016.

ACLD 2006-2011-2016-2021 linkage rates by selected characteristics (a)
 2006 panel sample (no.)2006-2011 linked records (no.)2006-2011 linkage rate (%)2006-2011-2016 linked records (no.)2006-2011-2016 linkage rate (%)2006-2011-2016-2021 linked records (no.)2006-2011-2016-2021 linkage rate (%)
SEX
Male480,288364,71876288,89360236,06249
Female499,374392,22779316,72563265,87953
 
AGE GROUP
0-14194,017141,56673114,5395999,79151
15-1966,24848,7047333,7805128,56343
20-2466,51045,5966932,8905028,08542
25-2962,24946,2827436,6105931,23650
30-39140,271113,8868195,3336882,20359
40-49142,910120,92985103,4657288,89362
50-59126,284107,3828592,0067378,04262
60-6986,38872,0438360,1827046,75654
70-7431,00424,2527818,2305911,37737
75 and over63,78136,3055718,583296,99511
 
INDIGENOUS STATUS
Non-Indigenous942,256733,03578588,53663489,57252
Aboriginal19,69712,450638,763456,21832
Torres Strait Island1,451938656744750035
Both Aboriginal and Torres Strait Islander839504603604325230
Not stated15,41910,018657,285475,39935
 
STATE/TERRITORY OF USUAL RESIDENCE
New South Wales323,137250,07077199,41962165,38951
Victoria244,098191,98279154,28063129,23753
Queensland192,609144,42875114,8586094,07049
South Australia75,47959,3877948,4236440,13653
Western Australia95,79573,9467759,2616248,82251
Tasmania23,78418,6247814,8156212,34352
Northern Territory8,4665,575664,055483,02236
Australian Capital Territory16,18812,8648010,453658,89255
Other Territories106696554513028
 
REMOTE AREAS
Major Cities669,275523,47278420,69163351,47253
Inner Regional195,399150,72377120,3206299,01451
Outer Regional92,39568,9407554,2855943,73447
Remote13,9869,843707,540545,88442
Very Remote6,5473,967612,782431,83728
No Usual Address2,026000000
Migratory34000000
        
TOTAL (b)(c)979,662756,94577605,61862501,94151
  1. Due to different confidentialisation methods used, data presented in the table may not align with other published counts.
  2. Includes Other Territories.
  3. Includes Migratory areas.
ACLD 2011-2016-2021 linkage rates by selected characteristics (a)
 2011 panel sample (no.)2011-2016 linked records (no.)2011-2016 linkage rate (%)2011-2016-2021 linked records (no.)2011-2016-2021 linkage rate (%)
SEX
Male600,727450,09075390,23165
Female620,332477,42777424,10668
 
AGE GROUP
0-14236,383189,64280171,56873
15-1979,97457,1157150,14363
20-2482,22152,0426345,84656
25-2985,19957,3316751,69961
30-39168,979127,97376116,96969
40-49172,579139,14081127,51874
50-59155,651127,70582116,03075
60-69121,03399,5358286,49072
70-7440,65832,2147924,74261
75 and over78,38244,8205723,33230
 
INDIGENOUS STATUS
Non-Indigenous1,171,792897,07377791,37468
Aboriginal29,15518,5176413,56847
Torres Strait Island1,8201,1766592051
Both Aboriginal and Torres Strait Islander1,2438046559348
Not stated17,0499,947587,88246
 
STATE/TERRITORY OF USUAL RESIDENCE
New South Wales393,516298,79476262,96667
Victoria304,511233,62177206,77568
Queensland245,366183,70575160,03965
South Australia91,55871,6517863,05469
Western Australia125,45295,0537682,76766
Tasmania28,58221,8287619,23667
Northern Territory11,6267,238625,44147
Australian Capital Territory20,27015,5327714,00169
Other Territories17895535833
 
REMOTE AREAS
Major Cities228,195174,58077151,93867
Inner Regional852,827651,86876578,56268
Outer Regional6416251219
Remote110,44482,4887570,06763
Very Remote2,5981,0003956522
No Usual Address16,5711,1464699,26356
Migratory10,3606,101593,93038
      
TOTAL (b)(c)1,221,059927,51776814,33767
  1. Due to different confidentialisation methods used, data presented in the table may not align with other published counts.
  2. Includes Other Territories.
  3. Includes Migratory areas.
ACLD 2016-2021 linkage rates by selected characteristics (a)
 2016 panel sample (no.)2016-2021 linked records (no.)2016-2021 linkage rate (%)
SEX
Male643,577526,31582
Female664,697561,99285
 
AGE GROUP
0-14246,316214,12187
15-1980,84366,45782
20-2487,31967,45777
25-2992,18973,66480
30-39182,646154,66385
40-49176,937154,18187
50-59166,133145,19587
60-69138,330119,49986
70-7449,15840,30582
75 and over88,40352,76560
 
INDIGENOUS STATUS
Non-Indigenous1,256,7571,054,84284
Aboriginal34,58923,17167
Torres Strait Island1,8681,27368
Both Aboriginal and Torres Strait Islander1,5451,01065
Not stated13,5158,01159
 
STATE/TERRITORY OF USUAL RESIDENCE
New South Wales419,045349,17183
Victoria328,748275,63284
Queensland264,504218,33983
South Australia94,09079,47685
Western Australia138,126113,92983
Tasmania28,26423,87285
Northern Territory13,0738,87468
Australian Capital Territory22,13518,83585
Other Territories28917962
 
REMOTE AREAS
Major Cities935,137784,72784
Inner Regional236,697197,86084
Outer Regional108,72187,62981
Remote15,08811,16074
Very Remote10,1875,61855
No Usual Address2,3761,27054
Migratory684363
    
TOTAL (b)(c)1,308,2741,088,30783
  1. Due to different confidentialisation methods used, data presented in the table may not align with other published counts.
  2. Includes Other Territories.
  3. Includes Migratory areas.

Weighting, benchmarking and estimation

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.

Weights were benchmarked to the following population groups:

  • State/territory by age groups (0-14 and ten-year groups to 85+) by sex, and
  • Indigenous status by state/territory.

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

Carefully consider which dataset and weight is most appropriate for your analysis based on the end point and in-scope population of your research. Multiple weights are available in the ACLD detailed microdata products, however, only one weight is available on each of the ACLD TableBuilder datasets. For further information see Using the ACLD in TableBuilder.

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).

Dataset NameWeight Scope (a)Population Benchmark (b)(c)Weights Mean Value MalesWeights Mean Value FemalesMinimum Weight ValueMaximum Weight Value
Australian Census Longitudinal Dataset, 2006-20112006-2011 (original linkage)Adjusted 2011 ERP24.824.017.1103.4
Australian Census Longitudinal Dataset, 2006-2011-2016-20212006-2011 (re-linkage)Adjusted 2011 ERP26.625.016.1176.9
2006-2011-2016Adjusted 2016 ERP31.529.415.9341.3
2006-2011-2016-2021Adjusted 2021 ERP36.233.416.8602.8
Australian Census Longitudinal Dataset, 2011-2016-20212011-2016Adjusted 2016 ERP23.222.314.883
2011-2016-2021Adjusted 2021 ERP25.123.814.6192.4
Australian Census Longitudinal Dataset, 2016-20212016-2021Adjusted 2021 ERP21.420.614.3123.5
  1. The weight scope refers to the sub-population of linked records across the different Census years. Each of these sub-populations have been weighted up to population counts.
  2. ERP = Estimated Resident Population. The end of June ERP was selected for each Census night.
  3. The ERP was adjusted by the estimated probability to cover the longitudinal population in scope.

In all ACLD datasets the mean weight was higher for people of Aboriginal and Torres Strait Islander origin and for people in the Northern Territory. For the 2006-2011 original linkage the mean weight was higher for people who moved interstate between 2006 and 2011.

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.

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.

For information on the quality of 2021 Census data see Managing Census quality, and for historic Censuses see Data Quality.  

The 2021 Census Statistical Independent Assurance Panel concluded that the 2021 Census data is fit-for-purpose, is of comparable quality to the 2011 and 2016 Censuses and can be used with confidence. For further information see Report on the quality of 2021 Census data: Statistical Independent Assurance Panel to the Australian Statistician.

Quality indicators

The ACLD contains several variables that relate to the quality of linkage 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 2006 and 2011, 2011 and 2016, and 2016 and 2021. Consistency flags 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 
  • Birthplace of Person 
  • Birthplace of Spouse or Partner 
  • 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 
  • Number of Children Ever Born.

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

In addition to the consistency flags, a "Record linked in YEAR” flag is also available. 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. 

Data consistency

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. For example, several 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

Other variables 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. 

Users are encouraged to read the Census dictionary variable pages to understand Census variables, concepts, and changes over time. See the 2021 Census dictionary or the historical dictionaries from previous Census years. For additional useful information about the quality of the variables in the ACLD see Quality Declaration

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 variable 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, 2016 or the 2021 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. 

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 variable, 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.

Proportion of linked records with inconsistent data

The following tables display the proportion of linked records with inconsistent data between the different Census years using the ACLD consistency flags.

Inconsistent reporting on the 2006-2011 ACLD (original linkage), 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 2006-2011-2016-2021 ACLD, by selected characteristics
CharacteristicProportion of linked records with
inconsistent data between 2006 and 2011 (a)
Proportion of linked records with
inconsistent data between 2011 and 2016 (a)
Proportion of linked records with
inconsistent data between 2016 and 2021 (a)
Age (by more than 1 year)0.32%0.38%0.34%
Sex0.03%0.06%0.10%
Birthplace of person4.28%2.38%1.57%
Birthplace of female parent5.27%2.57%1.37%
Birthplace of male parent5.25%2.75%1.66%
Year of arrival (b)2.46%2.31%1.98%
Indigenous status1.67%1.00%0.56%
Registered marital status0.34%0.21%0.17%
Highest year of school completed9.63%6.75%4.93%
Level of highest non-school qualification11.01%7.82%6.17%
Country of birth of spouse or partner (b)0.87%0.34%0.22%
Number of children ever born2.05%1.31%1.17%
  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 2011-2016-2021 ACLD, by selected characteristics
CharacteristicProportion of linked records with
inconsistent data between 2011 and 2016 (a)
Proportion of linked records with
inconsistent data between 2016 and 2021 (a)
Age (by more than 1 year)0.69%0.44%
Sex0.12%0.14%
Birthplace of person3.10%1.94%
Birthplace of female parent3.36%1.72%
Birthplace of male parent3.62%2.10%
Year of arrival (b)2.97%2.68%
Indigenous status1.32%0.70%
Registered marital status0.31%0.24%
Highest year of school completed7.69%5.78%
Level of highest non-school qualification9.06%7.44%
Country of birth of spouse or partner (b)0.45%0.30%
Number of children ever born1.61%1.42%
  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 2016-2021 ACLD, by selected characteristics
CharacteristicProportion of linked records with
inconsistent data between 2016 and 2021 (a)
Age (by more than 1 year)0.87%
Sex0.20%
Birthplace of person2.50%
Birthplace of female parent2.24%
Birthplace of male parent2.76%
Year of arrival (b)3.64%
Indigenous status0.92%
Registered marital status0.33%
Highest year of school completed6.83%
Level of highest non-school qualification8.92%
Country of birth of spouse or partner (b)0.40%
Number of children ever born1.73%
  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 2006-2011

Product overview

There are two ACLD 2006-2011 datasets which contain the original linkage that was released in 2013, these are:

  • Australian Census Longitudinal Dataset, 2006-2011 (with visa variables)
  • Australian Census Longitudinal Dataset, 2006-2011 (with experimental social security and related variables)

Both of these datasets are available in TableBuilder, however, only the Australian Census Longitudinal Dataset, 2006-2011 (with visa variables) is available as a detailed microdata product within the DataLab. 

The 2006-2011 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). The 2006-2011 ACLD dataset is recommended for analysis of the 2006-2011 longitudinal population.

New waves of Census data will not be added to these datasets but they have been retained and are recommended for analysis of visa class or social security information between 2006-2011.

Variables

The visa variables available on the Australian Census Longitudinal Dataset, 2006-2011 (with visa variables) are:

  • Location of visa
  • Application status
  • Visa type

The social security variable available on the Australian Census Longitudinal Dataset, 2006-2011 (with experimental social security and related variables) are the following for both person and partner and current and suspended:

  • DSS benefit abstudy
  • DSS benefit age pension
  • DSS benefit austudy
  • DSS benefit carer allowance
  • DSS benefit carer payment
  • DSS benefit child payment
  • DSS benefit disability support pension
  • DSS benefit family tax A
  • DSS benefit family tax B
  • DSS benefit newstart
  • DSS benefit parenting payment partnered
  • DSS benefit parenting payment single
  • DSS benefit partner allowance
  • DSS benefit sickness allowance
  • DSS benefit special
  • DSS benefit wife pension
  • DSS benefit youth allowance
  • DSS count of current benefits
  • DSS partner status (only available for person)

A complete list of variables (also known as data items) included on the ACLD datasets is provided in an Excel spreadsheet that can be accessed from the Data downloads section. 

All variables are created at the person level. This includes variables relating to the family and household of the persons selected in the sample.  

Variables differ between the TableBuilder and detailed microdata datasets so users should first refer to the data item lists before deciding which product will best suit their research needs.  

The ACLD contain quality indicators such as linkage indicators, consistency flags, imputation flags and movement indicators to assist with the assessment of the suitability of records for inclusion in analysis. For information about the quality of the variable in the ACLD please see the Quality Declaration. 

Users are encouraged to read the Census dictionary variable pages to understand Census variables, concepts, and changes over time. See the 2021 Census dictionary or the historical dictionaries from previous Census years. 

Not applicable categories

Most variables in the ACLD include a 'not applicable' category. The definition of the 'not applicable' category is provided in cell comments in the data item lists. Further information can be found in the  2021 Census dictionary or the historical dictionaries from previous Census years. 

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.

Unlinked records

The 2006-2011 ACLD contains all sample records from the 2006 panel, both those that were linked to a corresponding 2011 Census record and those that were not. Where records are linked they will contain information for that Census cycle. 

Where records are not linked to a future Census cycle all variables for the unlinked period will be set to "Unlinked record". 

There is a record not linked indicator available which can be used to select the records that have not been linked between 2006 and 2011, this is called: 

  • 2006 record not linked to 2011.

ACLD 2006-2011-2016-2021

Product overview

The 2006-2011-2016-2021 ACLD is a representative panel sample of almost one million records from the 2006 Census (wave 1) brought together with corresponding records from the 2011 Census (wave 2), 2016 Census records (wave 3), and 2021 Census records (wave 4). 

The 2006 panel sample of records was originally linked to the 2011 Census and released in 2013. A new linkage between the 2006 panel and 2011 Census records was used for this dataset to take advantage of improved linking methodology since the initial release. The linked 2011 records were then subsequently linked to records from the 2016 Census, and 2016 linked records then linked to 2021 Census records. 

The 2006-2011-2016 ACLD dataset in TableBuilder is the precursor to this dataset. As each TableBuilder dataset can only contain one weight variable, the 2006-2011-2016 ACLD TableBuilder dataset will be retained for analysis of the 2006-2016 population with the weights designed for this linked population. 

Three weight variables, each designed for the different linked populations, are available on the 2006-2011-2016-2021 ACLD detailed microdata dataset. 

The 2006-2011-2016-2021 ACLD dataset is recommended for analysis of the 2006-2011, 2006-2016 and 2006-2021 longitudinal populations. 

Variables

A complete list of variables (also known as data items) included on the ACLD datasets is provided in an Excel spreadsheet that can be accessed from the Data downloads section. 

All variables are created at the person level. This includes variables relating to the family and household of the persons selected in the sample.  

Variables differ between the TableBuilder and detailed microdata datasets so users should first refer to the data item lists before deciding which product will best suit their research needs.  

The ACLD contain quality indicators such as linkage indicators, consistency flags, imputation flags and movement indicators to assist with the assessment of the suitability of records for inclusion in analysis. For information about the quality of the variable in the ACLD please see the Quality Declaration

Users are encouraged to read the Census dictionary variable pages to understand Census variables, concepts, and changes over time. See the 2021 Census dictionary or the historical dictionaries from previous Census years. 

New and changed variables

There were several variable changes made at the time of releasing the 2021 Census (wave 4) data to the ACLD. This included the addition of the following Australian Defence Force and health conditions variables: 

  • Australian Defence Force service
  • Australian Defence Force service, detailed 
  • Count of selected long-term health conditions 
  • Whether has one or more long-term health condition(s). 

Additionally, more detailed data was added to the 2011, 2016 and 2021 versions of the following variables: 

  • Occupation variables - 6 digit level now included 
  • Industry of employment - 4 digit level now included 
  • Non-school qualification: field of study - 6 digit level now included. 

The following variables were added to the ACLD in March 2019: 

  • Birthplace of Female Parent (2016)
  • Birthplace of Male Parent (2016)
  • Child Type (including grandchildren) (2011, 2016)
  • Educational Institution: Attendee Status (2011, 2016) 
  • Engagement in Employment, Education and Training (2016) 
  • Engagement in Employment, Education and Training (male parent) (2016) 
  • Engagement in Employment, Education and Training (female parent) (2016) 
  • Engagement in Employment, Education and Training (spouse or partner) (2016) 
  • Family Blending (2011) 
  • Grandparent Families (2011, 2016)
  • Form Type (2016)
  • Household Family Composition (Dwelling) (2011, 2016) 
  • Imputation Flag for Number of Males and Females in Dwelling (2011, 2016) 
  • Imputation Flag for workplace address (2016) 
  • Index of Economic Resources (2011, 2016) 
  • Index of Education and Occupation (2011, 2016) 
  • Index of Relative Socio-economic Advantage and Disadvantage (2011, 2016) 
  • Index of Relative Socio-economic Disadvantage (2011, 2016) 
  • Labour Force and Hours Worked Not Stated (2011, 2016) 
  • Place of Work (2011, 2016)
  • Remoteness Areas (2016) 
  • Relationship in Household (including grandchildren) (2011, 2016) 
  • Number of Children Ever Born (ranges) (2011, 2016) 

Not applicable categories

Most variables in the ACLD include a 'not applicable' category. The definition of the 'not applicable' category is provided in cell comments in the data item lists. Further information can be found in the 2021 Census dictionary or the historical dictionaries from previous Census years. 

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.

Unlinked records

The 2006-2011-2016-2021 ACLD contains all sample records from the 2006 panel, both those that were linked to a corresponding 2011 Census record and those that were not. The linked 2011 Census records are then on-linked to 2016 records and the linked 2016 records onto the 2021 records. Where records are linked they will contain information for that Census cycle. 

Where records are not linked to a future Census cycle all variables for the unlinked period will be set to "Unlinked record". 

There are also record not linked indicators available which can be used to select the records that have not been linked between either 2006 and 2011, 2011 and 2016, and 2016 and 2021, these are called: 

  • 2006 records not linked to 2011 
  • 2011 record not linked to 2016 
  • 2016 record not linked to 2021. 

ACLD 2011-2016-2021

Product overview

The 2011-2016-2021 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) and 2021 Census records (wave 4). The 2011 Panel includes new births and migrants since the 2006 Census.

The 2011 panel sample of records has been linked to records from the 2016 Census and 2016 linked records then subsequently linked to 2021 Census records. 

The 2011-2016 ACLD dataset in TableBuilder is the precursor to this dataset. As each TableBuilder dataset can only contain one weight variable, the 2011-2016 ACLD TableBuilder dataset will be retained for analysis of the 2011-2016 population with the weights designed for this linked population. 

Two weight variables, each designed for the different linked populations, are available on the 2011-2016-2021 ACLD detailed microdata dataset. 

The 2011-2016-2021 ACLD dataset is recommended for analysis of the 2011-2016 and 2011-2021 longitudinal populations. 

Variables

A complete list of variables (also known as data items) included on the ACLD datasets is provided in an Excel spreadsheet that can be accessed from the Data downloads section. 

All variables are created at the person level. This includes variables relating to the family and household of the persons selected in the sample.  

Variables differ between the TableBuilder and detailed microdata datasets so users should first refer to the data item lists before deciding which product will best suit their research needs.  

The ACLD contain quality indicators such as linkage indicators, consistency flags, imputation flags and movement indicators to assist with the assessment of the suitability of records for inclusion in analysis. For information about the quality of the variable in the ACLD please see the Quality Declaration

Users are encouraged to read the Census dictionary variable pages to understand Census variables, concepts, and changes over time. See the 2021 Census dictionary or the historical dictionaries from previous Census years. 

New and changed variables

There were several variable changes made at the time of releasing the 2021 Census (wave 4) data to the ACLD. This included the addition of the following Australian Defence Force and health conditions variables: 

  • Australian Defence Force service
  • Australian Defence Force service, detailed 
  • Count of selected long-term health conditions 
  • Whether has one or more long-term health condition(s). 

Additionally, more detailed data was added to the 2011, 2016 and 2021 versions of the following variables: 

  • Occupation variables - 6 digit level now included 
  • Industry of employment - 4 digit level now included 
  • Non-school qualification: field of study - 6 digit level now included. 

The following variables were added to the ACLD in March 2019: 

  • Birthplace of Female Parent (2016)
  • Birthplace of Male Parent (2016)
  • Child Type (including grandchildren) (2011, 2016)
  • Educational Institution: Attendee Status (2011, 2016) 
  • Engagement in Employment, Education and Training (2016) 
  • Engagement in Employment, Education and Training (male parent) (2016) 
  • Engagement in Employment, Education and Training (female parent) (2016) 
  • Engagement in Employment, Education and Training (spouse or partner) (2016) 
  • Family Blending (2011) 
  • Grandparent Families (2011, 2016)
  • Form Type (2016)
  • Household Family Composition (Dwelling) (2011, 2016) 
  • Imputation Flag for Number of Males and Females in Dwelling (2011, 2016) 
  • Imputation Flag for Workplace Address (2016) 
  • Index of Economic Resources (2011, 2016) 
  • Index of Education and Occupation (2011, 2016) 
  • Index of Relative Socio-economic Advantage and Disadvantage (2011, 2016) 
  • Index of Relative Socio-economic Disadvantage (2011, 2016) 
  • Labour Force and Hours Worked Not Stated (2011, 2016) 
  • Place of Work (2011, 2016)
  • Remoteness Areas (2016) 
  • Relationship in Household (including grandchildren) (2011, 2016) 
  • Number of Children Ever Born (ranges) (2011, 2016) 

Not applicable categories

Most variables in the ACLD include a 'not applicable' category. The definition of the 'not applicable' category is provided in cell comments in the data item lists. Further information can be found in the 2021 Census dictionary or the historical dictionaries from previous Census years. 

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.

Unlinked records

The 2011-2016-2021 ACLD contains all sample records from the 2011 panel, both those that were linked to a corresponding 2016 Census record and those that were not. The linked 2016 Census records are then on-linked to 2021 records. Where records are linked they will contain information for that Census cycle. 

Where records are not linked to a future Census cycle all variables for the unlinked period will be set to "Unlinked record". 

There are also record not linked indicators available which can be used to select the records that have not been linked between either 2011 and 2016, and 2016 and 2021, these are called: 

  • 2011 record not linked to 2016 
  • 2016 record not linked to 2021. 

ACLD 2016-2021

Product overview

The 2016-2021 ACLD is a representative sample of 1.3 million records from the 2016 Census (wave 3) brought together with corresponding records from the 2021 Census (wave 4). The 2016 panel includes new births and migrants since the 2011 Census (and therefore the 2011 panel sample) and is a rich source for exploring how Australian society has changed between the 2016 and 2021 Censuses. 

This is the newest dataset added to the ACLD multi-panel suite. The detailed microdata was made available for approved users within the DataLab in February 2024. This dataset will be released to TableBuilder in early-mid 2024. 

The 2016-2021 ACLD product is recommended for analysis of the 2016-2021 longitudinal population.

Variables

A complete list of variables (also known as data items) included on the ACLD datasets is provided in an Excel spreadsheet that can be accessed from the Data downloads section. 

All variables are created at the person level. This includes variables relating to the family and household of the persons selected in the sample.  

Variables differ between the TableBuilder and detailed microdata datasets so users should first refer to the data item lists before deciding which product will best suit their research needs.  

The ACLD contain quality indicators such as linkage indicators, consistency flags, imputation flags and movement indicators to assist with the assessment of the suitability of records for inclusion in analysis. For information about the quality of the variable in the ACLD please see the Quality Declaration

Users are encouraged to read the Census dictionary variable pages to understand Census variables, concepts, and changes over time. See the 2021 Census dictionary or the historical dictionaries from previous Census years. 

Not applicable categories

Most variables in the ACLD include a 'not applicable' category. The definition of the 'not applicable' category is provided in cell comments in the data item lists. Further information can be found in the 2021 Census dictionary or the historical dictionaries from previous Census years. 

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.

Unlinked records

The 2016-2021 ACLD contains all sample records from the 2016 panel, both those that were linked to a corresponding 2021 Census record and those that were not.  

Where records are not linked to a future Census cycle all variables for the unlinked period will be set to "Unlinked record". 

There is a record not linked indicator available which can be used to select the records that have not been linked between 2016 and 2021, this is called: 

  • 2016 record not linked to 2021.

Using the ACLD in the 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. Controls in the DataLab have been put in place to protect the identification of individuals and organisations. All output from DataLab sessions is cleared by an ABS officer before it is released.  

For more information about the DataLab please see DataLab

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. 

Each person record has a weight. This weight indicates how many population units are represented by the sample unit. When producing estimates of sub-populations from the detailed microdata, it is essential that they are calculated by adding the weights of persons in each category and not just by counting the sample number in each category. The application of weights ensures that estimates will conform to an independently estimated distribution of the population by age, by sex, etc. rather than to the distributions within the sample itself.

There are multiple weights available in the detailed microdata datasets which contain data from more than two Census periods. You should use the weight that is most appropriate for your analysis based on the end point and the in-scope population of your research. 

Dataset NameAnalysis PeriodWeight Mnemonic
Australian Census Longitudinal Dataset, 2006-2011-2016-20212006-2011WEIGHT4_06_11
2006-2016WEIGHT4_06_11_16
2006-2021WEIGHT4_06_11_16_21
Australian Census Longitudinal Dataset, 2011-2016-20212011-2016WEIGHT4_11_16
2011-2021WEIGHT4_11_16_21

Using the ACLD in TableBuilder

TableBuilder user guide

The TableBuilder User Guide 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, 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 linked 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. Weights have only been created for, and applied to, linked records in the ACLD to enable longitudinal population estimates to be produced. 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. The weight applied in each ACLD TableBuilder dataset has been generated to enable analysis for the full longitudinal period. For example in the 2006-2011-2016-2021 ACLD dataset, this would be people from the 2006 panel sample who have been linked in 2011, 2016 and 2021. 

Carefully consider which dataset is most appropriate for your analysis based on the end point and the in-scope population of your research. Further information on the weight scope applied to the different TableBuilder datasets can be found in the table below.

Dataset NameWeight Scope (a)Population Benchmark (b)(c)
Australian Census Longitudinal Dataset, 2006-20112006-2011 (original linkage)Adjusted 2011 ERP
Australian Census Longitudinal Dataset, with Social Security and Related Information, experimental statistics, 2006-2011
Australian Census Longitudinal Dataset, 2006-2011-20162006-2011-2016Adjusted 2016 ERP
Australian Census Longitudinal Dataset, 2011-20162011-2016Adjusted 2016 ERP
  1. The weight scope in ACLD TableBuilder datasets refers to records which have been linked across all Census years available within the dataset. This is the sub-population which has been weighted up to population counts. 
  2. ERP = Estimated Resident Population. The end of June ERP was selected for each Census night.
  3. The ERP was adjusted by the estimated probability to cover the longitudinal population in scope.

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.

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 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.

Relative standard error

While weighted counts are available in the ACLD TableBuilder, the Relative Standard Error (RSE) 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.

An RSE count of 200 will appear in your TableBuilder tables, do not use these counts as they are not necessary.

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.

For further information see Perturbation in the TableBuilder User Guide

Data downloads

Data files

History of changes

Show all

23/02/2024
  • A correction has been made to the ACLD 06-11-16-21 linkage counts and weight values. 
06/02/2024
  • Information added relating to the 2016-2021 ACLD.
19/12/2023
  • Information added relating to the addition of the 4th wave of Census data (2021 data) to the ACLD.
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

Show all

Information on ACLD variables is available in the associated cell comment within the Data Items list which is available under Data downloads. Further information on terms and definitions can be found in either the current 2021 Census dictionary or the historical dictionaries from previous Census years. 

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. This ensures that confidentiality is maintained whilst enabling micro level data to be released. For more information on the confidentiality practices associated with TableBuilder see TableBuilder, User Guide and for DataLab see DataLab.

Relevance

Data for the Census of Population and Housing used in this product were collected on 8 August 2006, 9 August 2011, 9 August 2016 and 10 August 2021. 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.

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 three samples, 2006, 2011 and 2016, with each being representative of the Australian population at the time of the Census collection. 

Overseas visitors are excluded from the 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, 2006How Australia Takes a Census, 2011Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016, and Census Methodology, 2021. Additionally, see the 2021 Census dictionary or the historical dictionaries from previous Census years.

Timeliness

The Census of Population and Housing is conducted every five years. For further information see the publications How Australia Takes a Census, 2006How Australia Takes a Census, 2011Census of Population and Housing: Understanding the Census and Census Data, Australia, 2016 and Census Methodology, 2021.

The first wave of Census data for the ACLD was from 2006, the second wave was from 2011, the third wave was from 2016, and the fourth wave was from 2021. 

Microdata from the 2006-11 ACLD was first made available in December 2013. The 2011-16 data was available from February 2018, the 2006-11-16 data available from March 2019, and the link to the fourth wave of 2021 data from the 2006 and 2011 panels from December 2023.

Accuracy

The ACLD is a random 5% sample of persons enumerated in Australia on the Census Night in 2006, 2011 or 2016 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.  

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. 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 the TableBuilder, User Guide .

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 the different Censuses 
  • processing error - the value of a data item was inaccurately assigned or imputed during processing. 

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

Notable variables 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 variables were derived differently between Censuses. In these instances, to aid comparability, the 2006, 2011 and 2016 variables were re-derived to make them consistent with the 2021 derivation. 

For more information on the differences between the 2006, 2011 and 2016 Censuses see What's New for 2011?, What's New for 2016?, and What’s new for 2021? 

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 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, or search details by variable in the 2021 Census dictionary

Interpretability

This publication should be referred to when using the microdata. It contains information on the methodology, data quality, and information on how to use and apply for access to the ACLD.

Further information on methodology, linkage quality and weighting can be found in Information Paper: Australian Census Longitudinal Dataset, Methodology and Quality Assessment, 2006-2016. The ABS publishes extensive information on Census data quality, see Understanding data quality, 2021 or Census Data Quality.

Accessibility

The ACLD Datasets can be accessed through TableBuilder and the DataLab. To apply, see the TableBuilder and DataLab pages.

Previous catalogue number

This release previously used catalogue number 2080.0.

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