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USING THE CURF DATA
As a result, data on the CURF will not exactly match other previously published estimates. Any changes to the distribution of values are not significant and the statistical validity of aggregate data is not affected. Subject to the limitations of the sample size and the data classifications used, it is possible to interrogate the CURF, produce tabulations and undertake statistical analyses to individual specifications.
The 2010 CORMS Expanded CURF is a single level file containing 47,099 confidentialised records. Each record holds the person level data of a respondent to the survey. The file also includes some household characteristics applicable to the respondent such as 'Main source of household income'. Using the person weights provided for each record, the data can be used to estimate characteristics for the Australian population.
The file contains demographic information about each respondent including sex, age, country of birth and state/territory of usual residence. Some labour force information is also available such as: occupation, industry, hours worked, multiple job holders, number of jobs held in Australia and difficulties faced when looking for employment.
Migration and visa information including language spoken at home, citizen and visa status details, as well as educational attainment (level and field) before and after migration can be found in the file. Geographic identifiers are also included (i.e. state/territory of usual residence, capital city/balance of state).
The file is available in three formats (SAS, SPSS and STATA).
Each person has a unique random identifier - ABSPID.
To enable analysis at a regional level, each record on the CURF contains a state/territory identifier (STATEURC) and a part of state identifier (CCBOSCF). The CCBOSCF data item has two output categories - State capital city and Balance of state/territory. Only the statistical divisions for the six state capital cities defined in the Australian Standard Geographical Classification (cat. no. 1216.0) are classified as capital cities. All other regions in Australia, for example, the Australian Capital Territory (including Canberra) and the Northern Territory (including Darwin) are classified to the Balance of state/territory category.
Multiple Response Fields
A number of questions asked during the Characteristics of Recent Migrants survey allowed respondents to give more than one response. Three of these items are included on the CURF. Each response category for these multiple response questions is treated as a separate data item. These data items have the same general data item identifier (SAS name) but are each suffixed with a letter - A for the first response, B for the second response, C for the third response, D for the fourth response and so on. Each data item has either a 'Not applicable' or a valid response category. A 'Not applicable' response indicates that the response category is not relevant for the respondent.
An example of this is the 'All difficulties finding first job held in Australia' data item which has 8 response categories. From these categories eight separate data items have been produced - ALDIFJCA, ALDIFJCB, ALDIFJCC...ALDIFJCH, as defined in the data item list.
Therefore, as respondents are able to select more than one response, the sum of individual multiple response categories will be greater than the population - or the number of people applicable - to the particular data item.
The population relevant to each data item is identified in the data item list and should be borne in mind when extracting and analysing data from the CURF. The actual population count for each data item is equal to the total cumulative frequency minus the 'Not applicable' category.
Generally, all populations, including very specific populations, can be 'filtered' by using other relevant data items. For example, if the population of interest is 'Employed persons', any data item with that population (excluding the Not applicable category) can be used.
For example, the data items 'Full-time or part-time status of usual work' (FTPTWKA) and 'Occupation - ANZSCO 2006' (OCCECURF) are applicable to employed persons only. Therefore, either of the following filters could be used when restricting a table to 'Employed persons' only:
FTPTWKA > 0 or OCCECURF > 00
(Note: For these data items the 'Not applicable' categories (i.e. those persons who are not employed) are codes 0 and code 00 respectively and would be excluded from either population filter shown above).
Conversely, code 1 for the data item 'Labour force status' (LFSCURF) is 'employed persons'. Therefore, once again, if the population of interest is employed persons, this data item could be used as the filter (i.e. LFSCURF = 1).
Weights and Estimation
The CURF contains records of a sample of persons which can be weighted to infer results for the total in-scope population in Australia. The CURF contains one person weight, FINWT for each record. The application of the supplied weights ensures that weighted person estimates conform to an independently estimated distribution of the population by age, sex, state/territory and part of state. If weights were to be ignored, no account would be taken of a person's chance of selection in the survey or different response rates across population groups, with the result that population counts produced may be biased.
Standard errors for each estimate produced from this CURF can be calculated using the replicate weights provided on the file.
Each record of the CURF contains 30 sets of replicate weights, REP0101 to REP0130. Using these weights, it is possible to calculate the standard error for estimates produced from this file, using what is known as the delete-a-group Jack-knife standard error estimator.
To obtain the standard error of a weighted estimate, y, calculate the same estimate using each of the 30 replicate weights. The variability between these replicate estimates (denoting y(g) for group number g) is used to measure the standard error of the original weighted estimate y, using the formula:
= the replicate group number.
= the weighted estimate, having applied the weights for replicate group g.
= the weighted estimate from the full sample.
The delete-a-group Jack-knife method can be applied not just to estimates of population total, but also where the estimate y is a function of estimates of population total, such as a proportion, difference or ratio. For more information on the delete-a-group Jack-knife method of SE estimation, see Research paper: Weighting and Standard Error Estimation for ABS Household Surveys (Methodology Advisory Committee), July 1999 (cat. no. 1352.0.55.029), which is on the ABS web site.
Use of the delete-a-group Jack-knife method for complex estimates, such as regression parameters from a statistical model, is not straightforward and may not be appropriate. The method as described does not apply to investigations where survey weights are not used, such as unweighted statistical modelling.
Estimates are based on information collected in the survey month, and due to seasonal factors they may not be representative of other months of the year.
Comparison with previous CURFs
Labour Force Status and Other Characteristics of Recent Migrants, Expanded CURF, Australia, Nov 2007 (cat. no. 6250.0.25.002) and Characteristics of Recent Migrants, Expanded CURF, Nov 2010, have included migrants who arrived in Australia in the last 10 years (since 1997 and 2000 respectively), were aged 15 years and over on arrival, who had obtained permanent Australian resident status, as well as people who were temporary residents of Australia for 12 months or more.
In 2007, persons born in New Zealand, those holding New Zealand citizenship and those who held Australian citizenship prior to their arrival in Australia were excluded. In 2010, persons holding New Zealand citizenship and those who held Australian citizenship prior to their arrival in Australia were excluded, while other persons born in New Zealand were included. In 2010, this survey was conducted in both urban and rural areas in all states and territories, but excluded people living in Indigenous communities in very remote parts of Australia. Previous cycles of this survey have excluded all persons living in very remote areas.
Some new data items were collected in November 2010, including: whether would have preferred to have worked longer hours in first job in Australia; main reason not actively looking for work; and main language spoken on arrival.
Data items related to the last visa held before becoming an Australian Citizen, length of time spent overseas since most recent arrival, highest year of school completed and whether working full time or part time just before arrival were not collected in November 2010.
The label 'Type of visa on most recent arrival to live in Australia' was used incorrectly in 2007. The correct label 'Type of visa on arrival to live in Australia' has been used in the 2010. This data item has not changed, only the label used.
Data item list
A complete list of all data items included on the 2010 CORMS Expanded CURF is provided in the Excel spreadsheet (6250055001_DATA_ITEM_LISTING_CORMS10E.XLS) that accompanies this Technical Manual. The data items are grouped under the following broad topics:
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