6102.0.55.001 - Labour Statistics: Concepts, Sources and Methods, 2006  
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Contents >> Methods >> Household Collections >> Chapter 19. The Australian Census of Population and Housing

Labour Statistics: Concepts, Sources and Methods was originally released in 2001 in both electronic and paper versions (cat. no. 6102.0). The paper publication will not be rereleased. However, the web version (cat. no. 6102.0.55.001) is being updated on an ongoing basis. This chapter was updated on 30 March, 2006.

INTRODUCTION

19.1 The Australian Bureau of Statistics conducted the first Australian Census of Population and Housing in 1911. It was followed by others in 1921, 1933, 1947 and 1954. Following the 1961 Census, a census has been taken every five years. In 1977 an amendment was made to the Census and Statistics Act requiring that "the census shall be taken in 1981 and in every fifth year thereafter, and at such other times as prescribed".


19.2 The objectives of the census are threefold. They are:

    • to provide information to allow the determination of electoral boundaries;
    • to provide information for planning and the disbursement of government funding; and
    • to provide data for the construction of a master frame for a wide variety of household surveys.


CENSUS OUTPUT


19.3 Estimates from the 2001 Census were released in two phases, and a similar approach is proposed for the 2006 Census. For the 2001 Census, most data (approximately 80%) were released approximately 11 months after the census was conducted, with the remaining data released within the following twelve months. A number of products will provide data from the 2006 census similar to the 2001 outputs. Although many of the products released in 2001 will be available for 2006 a number of changes will be occurring, in particular relating to the dissemination platform. As was the case in 2001, the core Community Profiles will be available for 2006, however there will be some significant changes and enhancements.

These products include:
    • Community Profiles - sets of tables containing key census characteristics of persons, families, households and dwellings, covering most topics on the census forms. 2006 Community Profiles will be available via a new suite of electronic products on the ABS website.
    • Basic Community Profiles - includes sets of tables available for all standard census geographic areas from census collection districts (CDs) to total Australia. Basic community profiles are the standard census product from which most other standard products are created. For the first time, the 2006 edition will be disseminated on a Usual Residence basis. The data content of the profiles is reviewed with each census.
    • Other community profiles - a range of thematic profiles providing a standard set of two or three dimensional tables on such aspects as ethnicity, indigenous status, families, older persons, young people, place of enumeration, the working population, as well as a time series profile.
    • Hard copy publications for 2006 will include an expanded Social Atlas series as well as the new 'Statistician's Report'. This report will be a national compendium publication focussing on key Census information relating to persons, families and households. It will also contain tables, graphs and thematic mapping where appropriate, along with analytical commentary about the statistics presented.

19.4 A number of additional electronic products will be produced however the majority of these will be accessed via the ABS website. They include a new suite of internet based products aimed at novice through to intermediate and the more advanced census data users. Products include:
    • QuickStats : Basic summary data for your selected area of interest, along with textual descriptions.
    • QuickMaps : Easy access to basic thematically maps depicting selected populations, ethnicity, education, family, income etc
    • Census Topics : Enables the selection of a single table of data from a list (sourced from the Community Profiles) following the specification of a particular topic of interest by the user.
    • Census Tables : Similar to Census topics however it first requires the entry of a specific geography of interest
    • Community Profile Series : Detailed above.
    • Detailed Area Data : For intermediate to advanced users of Census data, this product enables the specification of an individual table of cross-classified data, and which can be manipulated within the confines of a defined data cube. This may be for an individual or combined geographic area of interest. In addition it will enable the mapping and/or charting of data.
    • Table Builder : Is the most advanced of our electronic product range and is aimed at the more experienced users. It will provide users with the freedom to design and populate their own tables via access to 100% of the Census Unit Record File. This product will be accessible through the ABS Remote Access Data Laboratory (RADL)
19.5 In addition to the products detailed above, the following products will also be available via CD-ROM as well as through the ABS website:
    • Socio-economic Indexes for Areas (SEIFA) - these indexes are summary measures derived from Census data to reflect differences in socio-economic conditions across geographic areas. The indexes are compiled for all standard geographic areas from CD to State/Territory.
    • Household Sample File - a sample file containing a one per cent sample of unidentifiable records for private dwellings and associated persons, and for persons in special dwellings. It is expected that the Household Sample File will also be available as a 5% sample through the RADL.
    • Census Basics - this CD-ROM product will contain all of the Community Profile data along with digital boundary data.

19.6 The census collects data on a range of topics. The criteria used to select topics for inclusion on the census form are outlined below (paragraph 19.7). The 2006 Census will collect information on the following topics:
Socio-demographic informationSex, age, relationship in household, marital status, usual residence on census night, usual residence one year ago, usual residence five years ago, religion, Australian citizenship, birthplace, year of arrival in Australia, Aboriginal or Torres Strait Islander origin, father's birthplace, mother's birthplace, language spoken at home, English proficiency, education, age left school, qualifications, ancestry, need for assistance, unpaid work and number of children ever born.
.
Labour-related informationLabour force status and income. For employed persons, information will also be collected on status in employment, occupation, hours worked, workplace address and method of travel to work. For unemployed persons, information will be collected on whether looking for full-time or part-time work.



SCOPE AND COVERAGE


19.7 The census aims to enumerate all persons residing in Australia on census night. The census is undertaken on a 'de facto' residence rather than 'de jure' residence basis: i.e. it is based on location on census night rather than on a usual residence basis.


19.8 Persons residing in the external territories of Cocos (Keeling) Islands and Christmas Island were included in the census for the first time in 1996. Persons enumerated in the census include almost all persons in Australia on census night, whether temporary or permanent residents. The only exceptions are diplomatic personnel of other nations resident in Australia. By definition it also excludes Australian residents temporarily overseas.



CONTENT


19.9 Topics for inclusion in the census must meet the following criteria:
    • the topic is of major national importance and in accordance with the objectives of the census; and
    • there is a defined need for data on the topic for small groups in the population or for small geographic areas. Otherwise, the need could be satisfied from a household survey; and
    • the topic is suitable for self-enumeration and meets sensitivity and privacy constraints.

19.10 Prior to a census there is considerable consultation with clients. Client consultation for the 2006 Census was initiated by the release of
Information Paper 2006 Census: ABS Views on Content and Procedures (Cat. no. 2007.0). This paper described the proposed topics for inclusion in the census and sought broad feedback. The paper was extensively advertised and widely distributed.

19.11 On receipt of submissions, a series of consultative meetings are held, culminating in seeking advice from the Australian Statistics Advisory Council. A report of the final recommendations is then prepared for approval by Cabinet.


19.12 Since the first national census in 1911, the content of censuses has changed. Some topics have been included in each census since 1911, for example age, marital status and religion, while others have been included or excluded depending on the importance of the topic at the time. For information on topics included in each census held from 1911 to
2006, see How Australia Takes a Census (Cat. no. 2903.0).


COLLECTION METHODOLOGY


19.13 The census is self
-enumerated. Forms and information booklets are distributed by census collectors to every household in Australia prior to census night. The completed forms are then collected in the week or so following census night. For the first time the Australian public will have the option to complete their 2006 Census form via the internet. The conduct of the census is complex. Various aspects of the collection methodology are discussed below. For more detail see How Australia Takes a Census (Cat. no. 2903.0).


CENSUS NIGHT


19.14 The date the census is conducted is carefully chosen. Recent censuses have been conducted in August, the month in which the least population displacement occurs. The day of the census varies, and is chosen to avoid school and other major holidays.



COLLECTION MANAGEMENT


19.15 A hierarchical structure of temporary staff is used to deliver and collect census forms. All staff are appointed under the
Census and Statistics Act 1905 and are subject to the strict confidentiality provisions of the Act.

19.16 ABS State and Territory Offices are responsible for the management of all field staff in their State or Territory. The majority of the workforce, just under 27,000 people, are the census collectors. These deliver a Census Form and Census Guide to every household in their collection district
(Footnote 1) prior to census night. They are also responsible for collecting forms following Census night.

19.17 As the census is self-enumerated, there is a heavy reliance on the ability of respondents to correctly interpret questions and to answer in the desired manner with the appropriate amount of detail. Collectors are encouraged to make contact with householders, since a high level of householder contact contributes to high response and a low under-enumeration rate. On receipt of the census forms from householders, census collectors are instructed to briefly scan them to ensure that they have been completed.


19.18 In total, more than 30,000 temporary field and collection staff will be involved in the delivery and collection of forms from the 2006 census. These staff need to be recruited, trained, supplied with material, supervised and paid on completion of their work. The development and logistics behind the census are enormous and require careful planning and implementation.


FORM DESIGN AND TESTING


19.19 A program of tests is conducted before each census to decide on the layout and question wording for the census form. A series of eight tests, including a dress rehearsal, was undertaken for the 2006 Census to make the forms as easy as possible for respondents to complete.

19.20 In addition, considerable consultation takes place among a variety of work groups within the ABS to ensure that:
    • the team responsible for the development of the processing system is satisfied with the positioning of response areas on the form and the way they are delineated;
    • the field operation team is satisfied with the proposed form from the perspective of training the collection workforce; and
    • the output team can satisfactorily use the reported data on the form as input to the compilation of specified output for publication.


PUBLIC RELATIONS


19.21 Significant investment is made in public communication and media relations activities to support Census field operations. Specialist communication staff are employed for the Census collection period, and an advertising campaign is conducted prior to the Census to highlight the importance of the census and how the community is expected to cooperate to ensure its success.

19.22 Public figures are recruited to lend their support to the Census. In 2006, a number of public figures, community and industry organisations will be invited to lend their support to the ABS by participating in a publicity campaign endorsing the Census.



PROCESSING OF CENSUS FORMS


19.23 A special Census Data Processing Centre is set up each census with the specific task of processing the completed census forms as quickly as possible and thereby achieving the timely release of results.

19.24 Completed census forms are examined for completeness and consistency. Write
-in responses on family, qualification and occupation are coded to the appropriate classification categories.

19.25 For the 2006 Census, in cases of partial non-response imputation will be undertaken for age, geographic area of usual residence and marital status. The number of males and females in 'non-contact' private dwellings may also be imputed. The remaining data items are set to 'not stated' unless other information exists on the form which allows the determination of Aboriginal/Torres Strait Islander origin and Labour Force Status.
The imputation method used for the 2006 Census is known as 'hotdecking', and is significantly different from previous methods of imputation used in the Census. In general this method involves locating a donor record and copying the relevant responses to the record requiring imputation. The donor record must have similar characteristics and must also have the required variable(s) stated. In addition the donor record is also located geographically as close as possible to the record to be imputed. For more information on imputation, see the 2006 Census Dictionary (Cat. No. 2901.0).


QUALITY CONTROL


19.26 As with other statistical collections, the ABS is concerned to see that high quality data are obtained from the census. To this end, extensive effort is put into the form design, collection procedures, public awareness campaign and accurate processing of the information collected.


Field testing


19.27 The method employed to obtain information in the census involves 'self-enumeration' in which each household is asked to complete the census form with relatively little assistance from the census collector. To make sure that this approach is successful, a series of tests
(Footnote 2) is conducted before each census to gauge public reaction to the form and the questions it contains.

Public awareness


19.28 As well as making sure that the right questions are asked, it is essential for the achievement of quality census data that everyone understands the importance of being counted and of giving the right answers in the census. A crucial factor in this respect is the public awareness campaign, discussed above in paragraph 19.19.


Quality assurance


19.29 Once the forms are in the Census Data Processing Centre, quality assurance procedures are implemented at all phases of processing to maximise the accurate recording of information collected and to eliminate as far as possible any inconsistencies in coding responses. Coding procedures, indexes, processing systems and training of staff are the key areas where changes can lead to improved data quality during processing.


Residual errors


19.30 The census, like all statistical collections, is subject to a number of sources of non-sampling error
(Footnote 3). However, testing has indicated that the effect of these errors is generally slight, although it could be more significant for analyses of data for small groups, or for very detailed cross classifications.

19.31 The four most significant sources of non-sampling error for the census are: undercounting; partial response; respondent error; and processing error. These are discussed further below.


Undercounting


19.32 Despite efforts to obtain full coverage of people and dwellings, it is inevitable that a small number of people will be missed and some will be counted more than once. In Australia more people are missed from the census than are counted more than once. The net effect when both factors are taken into account is referred to as undercounting.


19.33 As well as affecting the total population counts, undercounting can bias other census statistics because the characteristics of missed people are different from those of counted people. In Australia, rates of undercounting vary significantly for different population groups depending on factors such as age, sex and geographic area. A measure of the extent of undercoverage is obtained from a sample survey of households undertaken shortly after the census, called the Post Enumeration Survey. Undercounting of people in the 2001 Census was estimated to be 1.8% for Australia as a whole.


Partial response


19.34 People who are counted in the census do not necessarily answer all the questions which apply to them. While questions of a sensitive nature are generally excluded from the census, all topics have an element of non-response. However, this element can be measured and is generally low. In those instances where a response is not provided, a 'not stated' code is allocated, with the exception of non-response to age, sex, marital status and the statistical local area of usual residence. As these data are used in population estimates, these variables are imputed, using other information reported on the census form and specially constructed random tables based on the distribution of the population according to these variables at the previous census.


Respondent error


19.35 Most occurrences of respondent error are detected and corrected during editing. However, such procedures cannot detect and correct all errors, and some remain in the final output.


Processing error


19.36 Errors created during the processing of the census are kept at an acceptable level by means of quality assurance procedures. These involve sample checking during coding operations, and taking corrective action where necessary.


Evaluating the outcome


19.37 After the census, an evaluation of the data is carried out to inform users about their quality, and to help plan the next census. Evaluation includes investigation into the effects of partial response, consistency checks between related questions, and comparisons with data from other sources. Much of the information gathered about the quality of census data is distributed in the form of commentary contained in census products or in published working papers reporting on the evaluation of census data quality.


Introduced random adjustments


19.38 Minor adjustments are made to the information to allow the maximum detailed census data possible to be released without breaching the confidentiality of data reported by individual respondents. For this reason, great care should be taken when interpreting data in small cells, since possible respondent and processing errors have a greater proportional impact on them than on larger cells.



RELIABILITY OF THE ESTIMATES


19.39 Estimates from the census are subject to non-sampling error. For further information see paragraph 19.29 above.



DATA COMPARABILITY OVER TIME


19.40 In order to provide a high degree of consistency and comparability over time, changes are made as infrequently as possible to collection methods, collection concepts, data item definitions, frequency of collection, and analysis methods.


19.41 Table 19.1 shows the major changes to the labour-related data items in the census over its history.



19.1
MAJOR CHANGES TO LABOUR-RELATED DATA ITEMS IN THE CENSUS OF POPULATION AND HOUSING
CENSUS
EVENT
1911Census was established by the Census and Statistics Act 1905, and conducted in April.
Labour-related items included: labour force status; unemployment duration; occupation; and industry.

.
1921Census was conducted in April.
Labour-related data item added: cause of unemployment.

.
1933Census was delayed as a result of the economic depression, and moved to June.
Labour-related items collected in the 1933 Census were the same as those collected in the 1921 Census.

.
1947Census was delayed as a result of World War II, and conducted in June.
Labour-related items collected in the 1947 Census were the same as those collected in the 1933 Census.

.
1954Census conducted in June.
Labour-related data item changes: industry
- place of work also asked.
1961.
Census conducted in June, and the frequency increased to five-yearly intervals.
Labour-related data items collected in the 1961 Census were the same as those collected in the 1954 Census.

.
1966Census conducted in June.
Labour-related data items added: hours worked.
Labour-related data items dropped: unemployment duration and cause of unemployment.
Data released on microfiche for the first time.

.
1971Census conducted in June.
Labour-related data items added: journey to work
- collected by coding address of usual residence and address of workplace to obtain origins and destinations of travel to work.
Labour-related data item changes: hours worked
- question focused on hours worked in all jobs held in the week prior to the census.
ASIC introduced for industry coding.

.
1976Census conducted in June.
Labour-related data items added: mode of travel to work.

.
1977Census and Statistics Act amended to require censuses at five-yearly intervals 'and at such other times as prescribed.'
.
1981Census conducted in June.
Labour-related data items changed: labour force status
- since 1981 respondents are required to answer a series of questions from which labour force status is coded; hours worked in main job - replaced hours worked in all jobs.
.
1986Census conducted in June.
Labour-related data item changes: occupation
- an additional question on main tasks or duties performed in the job has been asked since 1986
.
1991Census moved to early August after all mainland States changed from three school terms to four school terms, with holidays around the end of June.
Labour-related data items the same as in 1986.

.
1996Census conducted in August.
Labour-related data items added: availability to start work
- to achieve comparability with Labour Force Survey definition of unemployment.
Labour-related data item changes: hours worked in all jobs
- replaced hours worked in main job.
Two stage release approach introduced, with users gaining access to a wide range of first release Census data within 12 months, and the second release data released progressively from that time.

.
2001Census conducted in August.
Two stage release approach expanded, with more data items available as part of the first release.
Introduction of intelligent character recognition, automatic coding and the use of images rather than paper forms during processing.
Option to have personal details retained and made publicly available after 99 years.
2006Census conducted in August
Introduction of the eCensus, an option allowing respondents to complete their Census form via the internet.
Introduction of 'hotdecking' method of imputation for partial non-response.




FURTHER INFORMATION


19.42 For further details contact the Labour Market Statistics Section, on Canberra (02) 6252 7206.


FOOTNOTES

1. The collection district (CD) is the basic geographic unit of collection. A CD is generally a census workload area that one Collector can cover, delivering and collecting census forms in a specified period. For further information see paragraph 16.41. < back

2. For further information see paragraph 19.17 above. < back

3. The Census of Population and Housing, like other types of fully enumerated collections, is not subject to sampling error - see Chapter 17 for further information. < back



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