USING THE CURF


ABOUT THE CURF
IDENTIFIERS
CURF FILE NAMES
INFORMATION FILES

ABOUT THE CURF

The data included in the SDAC 2009 CURF are released under the provisions of the Census and Statistics Act 1905. This legislation allows the Australian Statistician to release unit record data, or microdata, provided this is done “in a manner that is not likely to enable the identification of a particular person or organisation to which it relates.”

The ABS ensures the confidentiality of the data by:

• removing name, address and any other information that might uniquely identify any individual
• changing a small number of values - particularly unusual values - and removing very unusual records
• controlling the detail available for all records on the CURF
• perturbing or randomly adjusting income data
• excluding some data items that were collected
• controlling the modes of access to restrict access to more detailed data
• placing restrictions on how the data are used, supported by both information in the User Manual: Responsible Use of ABS CURFs, the undertaking signed by the head of each organisation and the terms and conditions signed by each user.

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.IDENTIFIERS

There is a series of identifiers that can be used on records at each level of the file.

File level identifiers

The identifiers ABSHID, ABSFID, ABSIID, ABSPID, ABSCID, ABSRSID, ABSSAID, ABSRCID, ABSBAID and ABSAPID appear on all levels of the file (as they are needed to create a hierarchical CSV file). Where the information for the identifier is not relevant for a level, it has a value of 0.

Each household has a unique twelve digit random identifier, (ABSHID). This identifier appears on the Household level, and is repeated on every other level. On the family level, each family within the household is numbered sequentially. The item ABSFID containing this family number also appears on the income unit and person level. The combination of household and family identifier uniquely identifies the family. On the income unit level, each income unit within the family is numbered sequentially. This income unit number is also stored at the person level (as ABSIID). A combination of household, family and income unit identifiers uniquely identifies an income unit. Records from the establishments component do not exist at the family and income unit levels. A person identifier (ABSPID) is assigned to each person within a combination of household, family and income unit identifiers. It should be noted that this is NOT the person number within a household, hence there may be more than one person with ABSPID=1 in a household. On the person level, the combination of household, family, income unit and person identifier (ABSPID) uniquely identifies the person. This information is also recorded on each lower level.

The broad areas of activity level and the assistance providers level also have an identifier (ABSBAID and ABSAPID respectively) which, when combined with ABSHID, ABSFID, ABSIID and ABSPID, enables information to be copied between levels nine and ten.

1. Household = ABSHID
2. Family = ABSHID, ABSFID
3. Income Unit = ABSHID, ABSFID, ABSIID
4. Person = ABSHID, ABSFID, ABSIID, ABSPID
5. All conditions = ABSHID, ABSFID, ABSIID, ABSPID, ABSCID
6. Restrictions = ABSHID, ABSFID, ABSIID, ABSPID, ABSRSID
7. Specific Activities = ABSHID, ABSFID, ABSIID, ABSPID, ABSSAID
8. All recipients =ABSHID, ABSFID, ABSIID, ABSPID, ABSRCID
9. Broad Activities = ABSHID, ABSFID, ABSIID, ABSPID, ABSBAID
10. Assistance providers = ABSHID, ABSFID, ABSIID, ABSPID, ABSBAID, ABSAPID

Collection component identifiers

The person level contains two items indicating whether the data were collected in the household or cared accommodation component. These items are POPESTAB and DWELTYPE. The item DWELTYPE has the categories 'Private dwelling' and 'Special dwelling' for all dwellings in the household component and 'Not applicable' for the cared accommodation component. The item POPESTAB has the category 'Living in an establishment' for the cared accommodation component and 'Not in this population' for the household component. These items can be copied from the person level to other levels of the file as required.

Copying information across levels
Identifiers can be used to copy information from one level of the file to another. The following SAS code (or equivalent) can be used to copy information from a lower level to a level above:

PROC SORT DATA=BRES; * Restrictions level file;
BY ABSHID ABSFID ABSIID ABSPID ;
RUN ;

DATA SUMMARY (KEEP=ABSHID ABSFID ABSIID ABSPID MENTUND) ;
SET BRES;
BY ABSHID ABSFID ABSIID ABSPID ;
RETAIN MENTUND ;
IF FIRST.ABSPID THEN MENTUND=2 ; * Initialise variable – Does not have learning or understanding difficulties or mental illness ;
IF RESTRCT=7 OR RESTRCT=14 THEN MENTUND=1 ; * Has learning or understanding difficulties or mental illness ;
IF LAST.ABSPID THEN OUTPUT ;
RUN ;

PROC SORT DATA = BPER; * Person level file ;
BY ABSHID ABSFID ABSIID ABSPID ;
RUN ;

DATA MERGE_FILE ;
MERGE SUMMARY (IN=A) BPER (IN=B) ;
BY ABSHID ABSFID ABSIID ABSPID ;
IF B AND NOT A THEN MENTUND=2 ; * Records which are not on the SUMMARY file ;
RUN ;

The SUMMARY file only keeps the last record for each person on the BRES file so the merge is a one to one match of person records on the SUMMARY file with records on the BPER file. Some BPER records will have no matching records on the SUMMARY file (as the person has no restrictions). For these records the statement 'If B and not A then MENTUND=2 ;' will allocate the code 2 because they don't have any restrictions. This method allows summary information from one level (e.g. Restrictions) to be used on the level above it in the hierarchy (e.g. Person). The item generated above can now be cross classified by any number of items on the person level file.

The following SAS code (or equivalent) can be used to copy information from a higher level to a level below:

PROC SORT DATA=BRES; * Restrictions level file;
BY ABSHID ABSFID ABSIID ABSPID ;
RUN ;

PROC SORT DATA = BPER; * Person level file;
BY ABSHID ABSFID ABSIID ABSPID ;
RUN ;

DATA MERGE_FILE ;
MERGE BRES (IN=A) BPER (KEEP=ABSHID ABSFID ABSIID ABSPID SEX AGEPB IN=B) ;
BY ABSHID ABSFID ABSIID ABSPID ;
IF A AND B THEN OUTPUT ; * Only keeps records which are present on both files ;
RUN ;

Unlike the previous merge, this merge will match one BPER record to many BRES records. The statement 'If A and B then OUTPUT;' ensures that only records present on both files are kept. If this statement was not used then BPER records without a corresponding BRES record would appear with a missing value for all BRES data items. Note that the data items copied from the BPER level will now have the counting unit for the level they have been added to, restrictions in this case.CURF FILE NAMES

The 2009 Basic CURF can be accessed on CD-ROM, files are available in SAS, SPSS and STATA formats. The CURF comprises the following files:

Data files

DAC09.CSV
This file contains the raw confidentialised survey data in hierarchical comma delimited ASCII text format.

SAS FILES
These files contain the data for the CURF in SAS format.

DAC09HH.SAS7BDAT contains the Household level data
DAC09FAM.SAS7BDAT contains the Family level data
DAC09IU.SAS7BDAT contains the Income Unit level data
DAC09PER.SAS7BDAT contains the Person level data
DAC09CON.SAS7BDAT contains the All Conditions level data
DAC09RES.SAS7BDAT contains the Restrictions level data
DAC09SPA.SAS7BDAT contains the Specific Activities level data
DAC09ALR.SAS7BDAT contains the All Recipients level data
DAC09BRA.SAS7BDAT contains the Broad Activities level data
DAC09PAS.SAS7BDAT contains the Assistance Providers level data

SPSS FILES
These files contain the data for the CURF in SPSS format.

DAC09HH.SAV contains the Household level data
DAC09FAM.SAV contains the Family level data
DAC09IU.SAV contains the Income Unit level data
DAC09PER.SAV contains the Person level data
DAC09CON.SAV contains the All Conditions level data
DAC09RES.SAV contains the Restrictions level data
DAC09SPA.SAV contains the Specific Activities level data
DAC09ALR.SAV contains the All Recipients level data
DAC09BRA.SAV contains the Broad Activities level data
DAC09PAS.SAV contains the Assistance Providers level data

STATA FILES
These files contain the data for the CURF in STATA format.

DAC09HH.DTA contains the Household level data
DAC09FAM.DTA contains the Family level data
DAC09IU.DTA contains the Income Unit level data
DAC09PER.DTA contains the Person level data
DAC09CON.DTA contains the All Conditions level data
DAC09RES.DTA contains the Restrictions level data
DAC09SPA.DTA contains the Specific Activities level data
DAC09ALR.DTA contains the All Recipients level data
DAC09BRA.DTA contains the Broad Activities level data
DAC09PAS.DTA contains the Assistance Providers level dataINFORMATION FILES

Data item list
The Data item list contains all the data items, including details of categories and code values, that are available on the Basic CURF.

Formats file
This file is a SAS library containing formats.

Frequency files

Household
A file containing documentation of the Household level data. Data item code values and category labels are provided with weighted household frequencies of each value. This file is in plain text format.

Family
A file containing documentation of the Family level data. Data item code values and category labels are provided with weighted household frequencies of each value. This file is in plain text format.

Income unit
A file containing documentation of the Income Unit level data. Data item code values and category labels are provided with weighted household frequencies of each value. This file is in plain text format.

Person
A file containing documentation of the Person level data. Data item code values and category labels are provided with weighted person frequencies of each value. This file is in plain text format.

Condition
A file containing documentation of the All Conditions level data. Data item code values and category labels are provided with weighted person frequencies of each value. This file is in plain text format.

Restrictions
A file containing documentation of the Restrictions level data. Data item code values and category labels are provided with weighted person frequencies of each value. This file is in plain text format.

Specific activities
A file containing documentation of the Specific Activities level data. Data item code values and category labels are provided with weighted person frequencies of each value. This file is in plain text format.

All recipients
A file containing documentation of the All Recipients level data. Data item code values and category labels are provided with weighted person frequencies of each value. This file is in plain text format.

Broad activity
A file containing documentation of the Broad Activities level data. Data item code values and category labels are provided with weighted person frequencies of each value. This file is in plain text format.

Assistance providers
A file containing documentation of the Assistance Providers level data. Data item code values and category labels are provided with weighted person frequencies of each value. This file is in plain text format.