3.1.2.1 CONSISTENT REPORTING OF INDIGENOUS STATUS
Consistency of Indigenous status is a special case, since the change in reporting over time is both a potential indicator of linkage quality, and is of analytical interest.
Results from the 2011 Census observed an unexpected increase in persons who identified as being of Aboriginal and/or Torres Strait Islander origin. This was due, in part, to improvements in Census collection practices that resulted in a more complete enumeration of the Aboriginal and Torres Strait Islander population in 2011 than in 2006. In addition, a significant contributor to this increase, was a change in the propensity of people to identify as being of Aboriginal and/or Torres Strait Islander origin in 2011 compared with 2006 (see Census of Population and Housing: Understanding the Increase in Aboriginal and Torres Strait Islander Counts, 2006-2011 (cat. no. 2077.0)).
While there was a group of people in the ACLD who were identified as non-Indigenous in 2006 and of Aboriginal and/or Torres Strait Islander origin in 2011, this group was relatively small and was counterbalanced by an almost equally sized group who reported the opposite. This pattern of change is different to that expected, given the increasing propensity of people to identify their Aboriginal and Torres Strait Islander origin observed at the aggregate level in the entire 2011 Census.
Throughout the linkage process, Indigenous status was used as a blocking and linking variable. Whilst this would have only made a small contribution to the linkage weight, this may have increased the likelihood of assigning a link to a record pair that contained consistent information for Indigenous status. Record pairs that contained inconsistent information for Indigenous status still had a good chance of being linked, however, providing there was sufficient additional information available for linking.
Differences in the reporting of Indigenous status between 2006 and 2011 on the ACLD may be due to a range of reasons. These include:
- people deliberately identifying their Indigenous origin differently at the two time points
- false links, where similar but not identical persons have been linked
- data capture errors, where multiple boxes may have been selected
- a different person filling out the Census form at each period of time and interpreting the question on Indigenous status differently
- transcription errors in the Census, where the wrong category is selected by accident.
Table 5 shows the reporting of Indigenous status for the linked records on the ACLD, across the 2006 and 2011 Censuses. Further
data cubes, demonstrating a more detailed breakdown, by remoteness areas, are provided as an attachment to this Information paper.
TABLE 5 - CONSISTENCY OF INDIGENOUS STATUS FOR LINKED RECORDS, 2006 and 2011