1. This page provides a reference of concepts, sources and methods etc. and the changes that occur from time to time that may impact the quality of overseas migration statistics. Changes can be due to any part of the end-to-end processing, from administrative passenger data collection to the dissemination of overseas migration statistics. They can range from the design, provision and collection of international passenger movement data through to the administrative systems and updates made by the Australian Government Department of Home Affairs. They can also result from better capture of passenger data, methodological improvements or improved processing systems.
Overseas Migration methodology
|ABS||Australian Bureau of Statistics|
|ACT||Australian Capital Territory|
|A T||Antarctic Territory|
|ASGS||Australian Statistical Geography Standard|
|cat. no.||catalogue number|
|COVID-19||coronavirus disease 2019|
|Dem Rep||Democratic Republic|
|DIAC||Australian Government Department of Immigration and Citizenship|
|DIBP||Australian Government Department of Immigration and Border Protection|
|DIMA||Australian Government Department of Immigration and Multicultural Affairs|
|E||East or Eastern|
|ERP||estimated resident population|
|E T||External Territories|
|Fr||France or French part|
|F S||Federated States of|
|FYROM||Former Yugoslav Republic of Macedonia|
|Gaza Str/W Bank||Gaza Strip and West Bank|
|Home Affairs||Australian Government Department of Home Affairs|
|LTRD||long-term resident departure|
|LTRR||long-term resident return|
|LTVA||long-term visitor arrival|
|LTVD||long-term visitor departure|
|N||North or northern|
|nec||not elsewhere classified|
|nfd||not further defined|
|NOM||net overseas migration|
|NSW||New South Wales|
|OAD||overseas arrivals and departures|
|OPC||Outgoing passenger card|
|PNG||Papua New Guinea|
|ROME||regional overseas migration estimates|
|ROADS||rebuild of the OAD system|
|S||South or Southern|
|SACC||Standard Australian Classification of Countries|
|SAR||Special Administrative Region|
|STRD||short-term resident departure|
|STRR||short-term resident return|
|STVA||short-term visitor arrival|
|STVD||short-term visitor departure|
|TRIPS||Travel and Immigration Processing System|
|UK, CIs & IOM||United Kingdom, Channel Islands and Isle of Man|
|USA||United States of America|
|W||West or western|
Armstrong, J & McDonald, C April 2016, Why the drivers of migration matter for the labour market, Reserve Bank of New Zealand, Analytical Notes, Wellington.
Commonwealth Consolidated Acts, Acts Interpretation Act 1901, http://classic.austlii.edu.au/au/legis/cth/consol_act/aia1901230/s33.html.
Commonwealth Consolidated Acts, Census and Statistics Act 1905, http://www.austlii.edu.au/au/legis/cth/consol_act/casa1905241/.
Commonwealth Consolidated Acts, Migration Act 1958 , http://classic.austlii.edu.au/au/legis/cth/consol_act/ma1958118/.
Commonwealth Consolidated Acts, Norfolk Island Legislation Amendment Act 2015, http://classic.austlii.edu.au/au/legis/cth/num_act//nilaa2015350/sch2.html.
United Nations 1998, Recommendations on Statistics of International Migration, Statistical Papers Series M, no. 58, rev. 1, Department of Economic and Social Affairs, Statistics Division, New York.
1. The classification of countries used in this release is the ABS' Standard Australian Classification of Countries, 2016. The entire historical series has been backcast using this version of the classification.
2. The statistics on country of residence or main destination have certain limitations because of reporting on passenger cards. For example, many travellers just list the UK on their passenger card rather than stating England, Scotland, Wales, or Northern Ireland.
State and territory
3. Overseas arrivals and departures data covers Australia and its states and territories, as defined by the Australian Statistical Geography Standard (ASGS) 2016. Jervis Bay Territory, the Territories of Christmas Island, Cocos (Keeling) Islands and Norfolk Island are included as one spatial unit at the State and Territory level under the category of Other Territories.
Historical changes to the State and Territory classification
4. Following the 1992 amendment to the Acts Interpretation Act, the Indian Ocean Territories of Christmas Island and the Cocos (Keeling) Islands were included as part of geographic Australia. To reflect this change, another category was created, known as Other Territories which also included Jervis Bay Territory (previously included with the Australian Capital Territory). Overseas arrivals and departures data for Other Territories commenced from February 1995.
5. Norfolk Island was included in the Other Territories category from July 2017 following the introduction of the Norfolk Island Legislation Amendment Act 2015. Prior to this, Norfolk Island was an external territory and not included within geographic Australia.
1. The ABS collects statistical information under the authority of the Census and Statistics Act, 1905. This requires that statistical output shall not be published or disseminated in a manner that is likely to enable the identification of a particular person or organisation.
2. Some techniques used to guard against identification or disclosure of confidential information in statistical tables are suppression of sensitive cells, random adjustments to cells with very small values and rounding. In these cases, data may not sum to totals due to the confidentialisation of individual cells.
3. The statistics in this release have been rounded to the nearest 10 to maintain confidentiality. Where figures have been rounded, discrepancies may occur between sums of component items and totals. All calculations and analysis are based on un-rounded data. Calculations made on rounded data may differ to those published.
4. To minimise risk of identifying individuals in aggregate statistics perturbation is sometimes used to randomly adjust cell values via services such as Table Builder. This technique involves small random adjustments of the data 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 patterns. After perturbation, a given cell value will be consistent across all tables. Where figures have been perturbed, discrepancies may occur between sums of component items and totals.
1. Administrative information on persons arriving in, or departing from, Australia is collected via various processing systems, passport documents, visa information, and incoming passenger cards (see Passenger card image section). Aside from persons travelling as Australian or New Zealand citizens, persons travelling to Australia are required to provide information in visa applications. These administrative data are collected by the Department of Home Affairs under the authority of the Migration Regulations 1994 made under the Migration Act 1958.
2 ABS statistics on overseas migration are mainly compiled using information from Home Affairs sources. All overseas movement records are stored on Home Affairs' Travel and Immigration Processing System (TRIPS).
3. Each month all overseas arrivals and departures (OAD) movement records and related information, including those matched to an incoming passenger card, are supplied to the ABS and then processed. This OAD data is then the main input to produce quarterly overseas migration estimates. OAD statistics and related data quality issues are published on a monthly basis in Overseas Arrivals and Departures, Australia (cat. no. 3401.0).
4. From July 2017, due to the removal of the outgoing passenger card, the ABS has also used Medicare enrolment data. This is a secondary source of state or territory of residence information for Australian residents and is used for a small proportion of records. For further information see ABS Privacy Impact Assessment Report 'Traveller Information and Medicare Enrolment PIA' released on the 12 September 2017.
5. Statistics in this release draw extensively on information provided by Home Affairs and Medicare. Their continued cooperation is very much appreciated: without it, the wide range of statistics published in the ABS on overseas migration would not be available. Information received by the ABS is treated in strict confidence as required by the Census and Statistics Act 1905.
12/12 month rule
Prior to 1 July 2006, overseas migration estimation methods used a '12/12 month rule' to determine if a traveller contributed to Australia's estimated resident population (ERP). This meant that in order for a person to have immigrated or emigrated, they must have stayed in, or remained absent from, Australia for a continuous period of 12 out of 12 months. For more detailed information see the history of changes in this methodology page.
12/16 month rule
From 1 July 2006, overseas migration estimation methods used a '12/16 month rule' to determine if a traveller contributed to Australia's estimated resident population (ERP). This meant that in order for a person to have immigrated or emigrated, they must have stayed in, or were absent from, Australia for a period of 12 out of 16 months. The 12 months does not have to be continuous and is measured over a 16-month period.
The 12/16 month rule therefore, takes account of those persons who may have left Australia briefly and returned, while still being resident for 12 months out of 16. Similarly, it takes account of Australians who live most of the time overseas but periodically return to Australia for short periods. For more detailed information see the history of changes in this methodology page.
For estimated resident population statistics, the Census year population estimates classify a person as an Australian resident if the person resides in Australia for 12 months or more. See also Estimated Resident Population (ERP) in this Glossary.
Australian Statistical Geography Standard (ASGS)
The ASGS brings all the regions for which the ABS publishe statistics within the one framework and has been in use for the collection and dissemination of geographically classified statistics since 1 July 2011. It is the current framework for understanding and interpreting the geographical context of statistics published by the ABS.
Prior to July 2006 a number of adjustments to overseas arrivals and departures were required. These mainly comprised adjustments designed to reflect differences between an individuals stated travel intentions (from the passenger card) and their actual recorded travel behaviour. If they changed from a long-term to a short-term traveller and vice versa it was referred to as 'category jumping'. For links to more detailed information see the history of changes in this methodology page.
Category of travel
Overseas Arrivals and Departures data are classified according to length of stay (in Australia or overseas), as recorded by travellers on passenger cards, or derived with reference to previous border crossings. There are three main categories of movement and 10 sub-categories:
- permanent arrivals (PA)
- permanent departures (PD) - only available prior to July 2007.
Long-term movement - has a duration of stay (or absence) of one year or more;
- long-term resident return (LTRR)
- long-term visitor arrival (LTVA)
- long-term resident departure (LTRD)
- long-term visitor departure (LTVD).
Short-term movement - has a duration of stay (or absence) of less than one year;
- short-term resident return (STRR)
- short-term visitor arrival (STVA)
- short-term resident departure (STRD)
- short-term visitor departure (STVD).
A census is the complete enumeration of a specific population at a point in time (as opposed to a survey, which enumerates a sample of the population). When the word is capitalised, "Census" refers to the national Census of Population and Housing. The Census is run by the ABS every five years and aims to count every person in Australia on Census night.
The Census of Population and Housing enumerates persons on the basis of where they were located on Census Night. The Census also compiles information on people according to their place of usual residence. This means that Census counts of people can be produced according to their location on Census Night as well as their place of usual residence. Characteristics of households are based on persons usually resident in a dwelling.
Country of birth
Country of birth refers to the country in which a traveller was born in. For Overseas Arrivals and Departures data and Overseas Migration data, the country of birth is usually collected from a traveller's passport or visa information.
Country of citizenship
Country of citizenship is the nationality of a person. For Overseas Arrivals and Departures data and Overseas Migration data, the country of citizenship is usually collected from a traveller's passport or visa information and in some cases from their passenger card.
Country of residence/stay
Country of residence/stay is the country a traveller indicates on their passenger card.
- For overseas visitors to Australia, it is their country of residence prior to travel as recorded on their passenger card or visa.
- For Australian residents, it is the country they spent the most time abroad (i.e. their country of stay).
The process of leaving one country to take up permanent or semi-permanent residence in another. See overseas migrant departures in this glossary.
Estimated resident population (ERP)
The official measure of the population of Australia is based on the concept of usual residence. It refers to all people, regardless of nationality, citizenship or legal status, who usually live in Australia, with the exception of foreign diplomatic personnel and their families. It includes usual residents who are overseas for less than 12 months over a 16 month period. It excludes overseas visitors who are in Australia for less than 12 months over a 16 month period.
Estimates of the Australian resident population are generated on a quarterly basis by adding natural increase (the excess of births over deaths) and net overseas migration (NOM) occurring during the period to the population at the beginning of each period. This is known as the cohort component method, and can be represented by the following equation:
Pt+1Pt+1 = PtPt + B - D + NOM, where:
PtPt = the estimated resident population at time point t
Pt+1Pt+1 = the estimated resident population at time point t+1
B = the number of births occurring between t and t+1
D = the number of deaths occurring between t and t+1
NOM = net overseas migration occurring between t and t+1.
For state and territory population estimates, an additional term is added to the equation representing net interstate migration (NIM) occurring between t and t+1, represented by the following equation:
Pt+1Pt+1 = PtPt + B - D + NOM + NIM.
The process of entering one country from another to take up permanent or semi-permanent residence. See overseas migrant arrivals in this glossary.
Intended length of stay
On arrival in Australia, all overseas visitors are asked to state their 'Intended length of stay in Australia'.
Long-term resident departures (LTRD)
Australian residents who stay abroad for 12 months or more. For a list of the categories see category of travel in this glossary.
Long-term resident returns (LTRR)
Australian residents returning after a recorded absence of 12 months or more overseas. For a list of the categories see category of travel in this glossary.
Long-term visitor arrivals (LTVA)
Overseas visitors who state that they intend to stay in Australia for 12 months or more (but not permanently). For a list of the categories see category of travel in this glossary.
Long-term visitor departures (LTVD)
Overseas visitors departing after a recorded stay of 12 months or more in Australia. For a list of the categories see category of travel in this glossary.
Main reason for journey
Overseas visitors/temporary entrants arriving in Australia and Australian residents returning to Australia are asked to state their main reason for journey using the following categories:
- visiting friends/relatives;
- education; and
Migrant - international
An international migrant is defined as "any person who changes his or her country of usual residence" (United Nations 1998). The country of usual residence is the country in which a person lives, that is to say, the country in which he or she has a place to live where he or she normally spends the daily period of rest. A long-term international migrant is a person who moves to a country other than that of his or her usual residence for a period of at least a year (12 months), so that the country of destination effectively becomes his or her new country of usual residence.
In Australia, for the purposes of estimating overseas migration, and thereby the official population counts, a person is regarded as a usual resident if they have been (or expected to be) residing in Australia for a period of 12 months or more over a 16 month period.
The movement of people across a specified boundary for the purpose of establishing a new or semi-permanent residence. Migration can be international (migration between countries) and internal (migration within a country).
Prior to July 2006 a number of adjustments to overseas arrivals and departures were required. These mainly comprised adjustments designed to reflect differences between an individuals stated travel intentions (from the passenger card) and their actual recorded travel behaviour. If they changed from a long-term to a short-term traveller and vice versa it was referred to as 'category jumping'. In addition, adjustments were also required to transform numbers of overseas movements into numbers of travellers (combined they were referred to as 'migration adjustments'). For links to more detailed information see the history of changes in this methodology page.
Net overseas migration (NOM)
Net overseas migration is the net gain or loss of population through immigration to Australia and emigration from Australia. Under the current method for estimating final net overseas migration this term is based on a traveller's actual duration of stay or absence using the '12/16 month rule'. Preliminary NOM estimates are modelled on patterns of traveller behaviours observed in final NOM estimates for the same period one year earlier.
NOM is calculated as follows:
- NOM = overseas migrant arrivals - overseas migrant departures
Other territories include Christmas Island, Cocos (Keeling) Islands, Jervis Bay Territory and Norfolk Island. For more information see the classifications section in this methodology page.
Overseas arrivals and departures (OAD)
Overseas arrivals and departures (OAD) refer to the recorded arrival or departure of persons through Australian air or sea ports (excluding operational air and ships' crew). Statistics on OAD relate to the number of movements of travellers rather than the number of travellers (i.e. the multiple movements of individual persons during a given reference period are all counted).
Overseas migrant arrivals
Incoming international travellers who stay in Australia for 12 months or more over a 16-month period, who are not currently counted within the population, and are then added to the population. Overseas migrant arrivals are also referred to as immigrants.
Overseas migrant departures
Outgoing international travellers who leave Australia for 12 months or more over a 16-month period, who are currently counted within the population, and are then subtracted from the population. Overseas migrant departures are also referred to as emigrants.
See net overseas migration (NOM).
Passenger cards are completed by nearly all passengers arriving in Australia. Information including: country of previous residence, intended length of stay, main reason for journey, and state or territory of intended stay/residence is collected. An example of the current Australian passenger card is provided under 'Passenger card images' in the left hand side navigation bar.
- travellers who arrive on a permanent migrant visas for the first time;
- New Zealand citizens who indicate for the first time an intention to migrate permanently; and
- those who are otherwise eligible to settle (e.g. overseas born children of Australian citizens).
For a list of the categories see category of travel in this glossary.
A visa allowing the holder to remain indefinitely in Australia's migration zone.
Place of usual residence
See usual residence.
Rebasing of population estimates
After each Census, the ABS uses Census counts (adjusted for undercount) to construct a new base population figure for 30 June of the Census year. Rebasing is the process of updating population estimates for the five years between Censuses, to incorporate information from the most recent Census.
Residents temporarily overseas (RTO)
Residents temporarily overseas are outgoing international travellers (Australian residents and long term visitors to Australia) who are currently counted within the population and who leave Australia for less than 12 months over a 16 month period.
Regional overseas migration estimates (ROME)
The movement of people to or from Australia's regions through immigration or emigration, where travellers satisfy the 12/16 month rule.
Sex ratio is the number of males per 100 females.
Short-term resident departures (STRD)
Australian residents who stay abroad for less than 12 months. For a list of the categories see category of travel in this glossary.
Short-term resident returns (STRR)
Australian residents returning after a recorded stay of less than 12 months overseas. For a list of the categories see category of travel in this glossary.
Short-term visitor arrivals (STVA)
Overseas visitors who intend to stay in Australia for less than 12 months. For a list of the categories see category of travel in this glossary.
Short-term visitor departures (STVD)
Overseas visitors departing after a recorded stay of less than 12 months in Australia. For a list of the categories see category of travel in this glossary.
Those categories of the Migration Program where the core eligibility criteria are based on the applicant's employability or capacity to invest and/or do business in Australia. The immediate accompanying families of principal applicants in the skill stream are also counted as part of the skill stream.
This definition of skill stream is used by Home Affairs who administer the Migration Program.
State or territory of residence/stay
See state or territory of usual residence.
State or territory of usual residence
State or territory of usual residence refers to the state or territory of usual residence of:
- the population (estimated resident population);
- the mother (birth collection); and
- the deceased (death collection).
In the case of overseas movements, state or territory of usual residence refers to the state or territory regarded by the traveller as the one in which he/she lives or has lived. State or territory of intended residence is derived from the intended address given by settlers, and by Australian residents returning after a journey abroad. Particularly in the case of the former, this information does not necessarily relate to the state or territory in which the traveller will eventually establish a permanent residence.
See temporary visas.
Temporary entrant visas are visas permitting persons to come to Australia on a temporary basis for specific purposes. Main contributors are tourists, international students, those on temporary work visas, business visitors and working holiday makers.
Within Australia, usual residence is the address of the dwelling at which a person considers themselves to currently live, either having lived there for some time or intending to live there for some time.
The usual residence of a newborn is that of the mother.
Permission or authority granted by the Australian government to foreign nationals to travel to, enter and/or remain in Australia for a period of time or indefinitely.
History of changes
History of methods used to measure overseas migration
1. Due to changes in the methods used to measure overseas migration estimates, caution should be used comparing them over time. This is especially so for estimates based on the '12/12 month rule' method compared to those using the '12/16 month rule' method. The table below describes the various methods used in Australia that have been applied to measuring overseas migration.
|Reference Period||Method used|
|Prior to Sep qtr 1971||The difference between the total overseas arrival and departure movements provided an estimate for net overseas migration(a)|
|Sep qtr 1971 - Jun qtr 1997||Permanent and long-term arrival and departure movements direct from OAD were used with 'Category jumping' adjustments applied (12/12 month rule)(b)|
|Sep qtr 1997 - Jun qtr 2001||Permanent and long-term arrival and departure movements direct from OAD were used. No adjustments applied (i.e. 'category jumping' set to zero) (12/12 month rule)(c)|
|Sep qtr 2001 - Jun qtr 2006||Permanent and long-term arrival and departure movements direct from OAD were used with Migration adjustments applied, based at the aggregate level (12/12 month rule)(d)(e)|
|Sep qtr 2006 - Jun qtr 2011||Actual duration of stay/absence, based at the individual traveller level (12/16 month rule)(f)(g)(h)(i)|
|Sep qtr 2011 - Mar qtr 2020||Actual duration of stay/absence, based at the individual traveller level (12/16 month rule) - changes to input data(j)(k)|
|Sep qtr 2020 - Mar qtr 2021||Propensity method using observed behaviour of similar travellers from one year earlier is re-run and estimates revised as more input data become available (12/16 month rule)|
|Jun qtr 2021||Propensity method using observed behaviour of similar travellers from one year earlier, based at the individual traveller level (12/16 month rule)(j)(k)|
Note: OAD is overseas arrivals and departures data.
- See Table 7. Migration under the data downloads in Historical population, 2019 (cat. no. 3105.0.65.001)
- See Category jumping: trends, demographic impact and measurement issues, 2000 (cat. no. 3122.0).
- See Estimated resident population and measurement of category jumping, 2003 (cat. no. 3133.0).
- See Net overseas migration: adjusting for actual duration of stay or absence, 2003 (cat. no. 3137.0).
- See Measuring net overseas migration, method used September quarter 2001 to June quarter 2006 (cat. no. 3412.0).
- See Improved methods for estimating net overseas migration, 2006 (cat. no. 3107.0.55.003).
- See Statistical implications of improved methods for estimating net overseas migration, Australia, 2007 (cat. no. 3107.0.55.005).
- See '12/16 month rule' methodology for calculating net overseas migration from September quarter 2006 onwards (cat. no. 3412.0).
- See Improving net overseas migration estimates, 2010 (cat. no. 3412.0.55.001).
- See Further improvements to net overseas migration estimation, 2013 (cat. no. 3412.0.55.002).
- See Improvements to the estimation of net overseas migration, 2018 (cat. no. 3412.0.55.004).
Pre 2006 - the 12/12 month rule
2. Prior to 1 July 2006, overseas migration estimation methods used a '12/12 month rule' to determine if a traveller contributed to Australia's estimated resident population (ERP). This meant that in order for a person to have immigrated or emigrated, they must have stayed in, or were absent from, Australia for a continuous period of 12 out of 12 months.
3. Conceptually, migration estimates are based on counts of travellers rather than counts of overseas movements since travellers may have more than one movement in a particular reference period. Prior to July 2006 a number of adjustments to overseas arrivals and departures were required. These mainly comprised adjustments designed to reflect differences between an individual's stated travel intentions (from the passenger card) and their actual recorded travel behaviour. If they changed from a long-term to a short-term traveller and vice versa it was referred to as 'category jumping'. In addition, adjustments were also required to transform numbers of overseas movements into numbers of travellers (combined they were referred to as 'migration adjustments'). For more information refer to footnotes (d) and (e) in the table above.
From 2006 - why the change to the 12/16 month rule
4. During a reconciliation of the 1996-2001 intercensal population growth estimates with the results of the 2001 Census of Population and Housing, the ABS identified a number of inconsistent results for the overseas migration estimates. These inconsistencies arose from a 1998 passenger card processing change and the measurement of temporary migration.
5. The ABS noted that the precise measurement of duration of stay in Australia (or absence) using a comparison of border crossing transactions may lead to a misleading categorisation of frequent travellers to short-term, when their overall period of stay or absence in a broader context was long-term punctuated by short journeys. For example, an international student in Australia for a three, or four, year course of study, who leaves Australia briefly each year for holiday or other reasons, would incorrectly not be added to estimates of Australia's population. This was because after the passage of time, they did not spend a continuous period of 12 months in Australia during their long-term period of stay in Australia (the previous '12/12 month rule' method of measurement). This was inconsistent with the intention behind the definition of an overseas (or international) migrant by the United Nations (United Nations 1998, 36) and the ABS' ERP conceptual definition. The use of single continuous periods of stay as the criteria (i.e. 12 continuous months) for classifying travellers was seen as a major shortcoming in the measurement of migration and consequently estimates of Australia's resident population.
6. Further, there were some travellers who self-identified as permanent immigrants and emigrants on Australian passenger cards, yet it was observed after less than a year, some permanent immigrants departed Australia and some permanent emigrants returned to Australia. The ABS also identified a need to convert the multiple border movements information for frequent travellers within a reference period to individual person estimates together with their travel history over time to avoid double counting.
7. The method for estimating overseas migration was reviewed in 2004 in response to the issues arising with the previous estimation of category jumping (i.e. changes between stated intended duration and actual duration). The review also addressed the changing patterns of migration, in particular the increased propensity for travellers to interrupt longer periods of stay or absence with short-term trips.
8. The change to a '12/16 month rule' method was adopted by the ABS for measuring overseas migration and has been contributing to Australia's ERP since September quarter 2006. It more closely aligns with the intention behind the international definitions set out by the United Nations (United Nations 1998, 36). The ABS has not changed the statistical conceptual definition of overseas migration. However, the method of measurement changed.
2017 - outgoing passenger card removed
9. In an initiative to create a more efficient and streamlined process for travellers departing Australia, the outgoing passenger card was removed by the Department of Home Affairs from 1 July 2017. Due to the removal of the card, the ABS reviewed its overseas migration methodology and processing systems. From this review the most significant changes were:
- The inclusion of an additional month of movement data (allowing four months after the reference period) — this further reduced the pool of travellers required to use the propensity model, improving the accuracy of preliminary migration estimation;
- Changes in data sources for state/territory of residence — data previously sourced from the outgoing passenger card is now collected from an incoming passenger card for that traveller or information from Medicare enrolment records for Australian residents;
- Incorporating improvements to the personal identifier (known as PID) for movement records — a consistent PID for each traveller is crucial for determining a traveller's actual duration in or out of the country. Updated PID data is supplied by Home Affairs each month and used to improve the quality of travel histories that are produced for each traveller.
10. Historical estimates from September quarter 2011 onwards were revised using the new methods. Analysis had shown that the revision between preliminary and final estimates, using the new methodology, had also improved when compared to the previous method. For more information refer to footnote (k) in the table above.
11. For detailed information on the 2017 changes to the main input data, overseas arrivals and departures data, including imputation, secondary sources used and information on the state/territory of residence, see History of changes in Overseas Arrivals and Departures, Australia, methodology (cat. no. 3401.0).
The 12/16 month rule
1. The method used in Australia for estimating overseas migration employ the '12/16 month rule'. For the purposes of overseas migration, a person is added to the estimated resident population (ERP) if they have been (or expect to be) residing in Australia for 12 months or more (i.e. an overseas migrant arrival) thus becoming an Australian resident. Likewise, an Australian resident is removed from the population if they leave Australia for 12 months or more (i.e. an overseas migrant departure). The 12 months does not have to be continuous and is measured over a 16-month period.
2. To measure a traveller's actual duration of stay the ABS uses a unique personal identifier provided with the administrative data supplied by Home Affairs. To be able to apply the '12/16 month rule', the personal identifier is used to match a traveller's movements over time and construct a traveller's movement history recording each arrival and departure. This method creates a history for each and every traveller who cross Australia's international border.
Preliminary estimates and the propensity model
3. Preliminary estimates of overseas migration are required within six months after the reference quarter for the production of quarterly estimates of the population of Australia and the states and territories. At this time, complete traveller histories for the 16 months following a reference quarter cannot be produced. To provide preliminary estimates, the ABS uses a propensity model that estimates a traveller's propensity to contribute to overseas migration using the observed behaviour of similar travellers from one year earlier. Travellers with similar characteristics are grouped according to specific variables. The variables used are: age, country of citizenship, direction of first and last movement in the reference quarter, initial ERP status, time spent out of Australia, and visa group. To create the preliminary estimates, the migration propensities determined for the donor groupings from one year earlier are applied to similarly grouped travellers from the reference quarter being estimated.
Reducing the pool of travellers that use the propensity model
4. The majority of overseas travellers in a given reference quarter take a trip of short duration. Most short-term travellers can have their ERP status determined based on data available at the time of estimation. This means for many individuals that their ERP status can be resolved without the need for them to be processed through the preliminary propensity model. For example, an Australian resident counted in the ERP at the beginning of a quarter, may commence a holiday during that quarter and then return to Australia two weeks later. Once four months since his/her return has passed without a further departure, he/she can be determined to still be in Australia’s population at the end of the reference quarter. This is because, as counted from the date of their original departure, it will no longer be possible for him/her to be out of Australia for more than 12 months out of 16.
5. The pool of travellers requiring preliminary estimation by the propensity model reduces the proportion to less than 30%. This significantly increases the predictive accuracy of the model.
Preliminary revised estimates and further reducing the pool of travellers
6. As mentioned above, most short-term travellers can have their ERP status determined based on data available at the time of estimation. However, as more time passes after the initial overseas movement, the ERP status can be determined for more individuals. Therefore, as each new quarters data becomes available the pool of travellers requiring estimation by the propensity model for the original reference period reduces further and a revision is applied to the original preliminary estimation.
Fully revised estimates - applying the 12/16 month rule
7. It is with the fully revised overseas migration estimates that the '12/16 month rule' can be fully applied. A traveller's actual duration of stay can only be calculated when data on overseas movements becomes available for the full 16 months following a reference period. Fully revised estimation methods use ERP flags to determine if a traveller, through their actual duration of stay being in or out of Australia for 12 months or more, should be included or excluded from the overseas migration estimates and consequently ERP.
Passenger card images
Incoming card - front
Incoming card - front
Incoming card - back
Incoming card - back
1. The status of quarterly overseas migration estimates changes over time from preliminary, to revised, to final.
2. Although this release reports on annual data, the ABS produces estimates each quarter. Overseas migration, at the national level, is one of the three components of population change (birth, deaths and overseas migration). The migration estimates contribute to the ABS' population estimates and are released each quarter in the National, state and territory population publication (cat. no. 3101.0).
|Reference Period||Revision Status - Overseas Migration||Revisions explained|
|Up to Jun qtr 2016||Final||Before each intercensal period is completed and population re-basing occurs, a final quality assurance examination of the migration data is undertaken. If required, final revisions are made and the data for the 5 year intercensal period is then made final and will not be subject to any further revisions.|
|Sep qtr 2016 - Jun qtr 2020||Final||A traveller's actual duration of stay can only be calculated when data on all overseas movements becomes available for the full 16 months following a reference period. The 12/16 month rule can then be fully applied.|
|Sep qtr 2020 - Mar qtr 2021||Preliminary revised||As new input data becomes available over time the propensity method using observed behaviour of similar travellers from one year earlier can be re-run and data revised.|
|Jun qtr 2021||Preliminary||Propensity method applied - uses observed behaviour of similar travellers from one year earlier.|
1. Recommendations of the United Nations state an international migrant is defined as "any person who changes his or her country of usual residence". With regard to the element of time "the change of country of usual residence necessary to become an international migrant must involve a period of stay in the country of destination of at least a year" (United Nations 1998, 32 & 36).
2. In Australia, for the purposes of overseas migration (or international migration), a person is added to the population if they have been (or expect to be) residing in Australia for 12 months or more (i.e. an overseas migrant arrival) thus becoming an Australian resident. Likewise, an Australian resident is removed from the population if they leave Australia for 12 months or more (i.e. an overseas migrant departure). The 12 months does not have to be continuous and is measured over a 16-month period.
3 Conceptually, the term net overseas migration (NOM) is the difference between the number of overseas migrant arrivals and the number of overseas migrant departures. Therefore, whether an international traveller is counted in or out of the population is determined by their exact duration of stay in or away from Australia over the subsequent 16 months after arrival or departure. To identify overseas migrants, all recorded movements of travellers who cross Australia's international border are processed to assess their exact duration of stay.
4. Australia's measurement of overseas migration includes all international travellers regardless of nationality, citizenship or legal status, with the exception of foreign diplomatic personnel and their families.
5. Statistics on overseas migration exclude: all travellers whose duration of stay is less than 12 months; operational air and ships' crew; travellers in transit who pass through Australia but are not cleared for entry; passengers on pleasure cruises commencing and finishing in Australia. From 1 July 2006, foreign diplomatic personnel and their families were also able to be excluded.
Statistics and variables available
1. The ABS may have other relevant data available on request. Generally, a charge is made for providing this information. Inquiries should be made to the National Information and Referral Service on 1300 135 070.
2. The following variables for overseas migration data may be made available on request:
- Country of birth
- Country of citizenship (nationality)
- Country of previous residence
- Category of travel (permanent departures not available from Sep quarter 2011)
- Main reason for journey (not available for permanent movements, residents departing or visitors departing)
- Marital status (not available from Sep quarter 2011 or for Australian and New Zealand citizens)
- Reference quarter/year (available from Dec quarter 2003)
- State or Territory of residence
- Status (preliminary, revised or final)
- Visa applicant type (primary or secondary applicant - available from Sep quarter 2011)
- Visa subclass (includes separate groups for Australian citizens and NZ citizens)