SOCIO-ECONOMIC INDEXES FOR AREAS 96 - YOUR QUESTIONS ANSWERED
Paul Schubert from the ABS' Methodology Division answers some commonly asked questions about Socio-Economic Indexes For Areas 96 (SEIFA96).
Q: What are the socio-economic indexes?
A: The socio-economic indexes are five summary measures derived from the 1996 Census of Population and Housing to measure different conditions by geographic area. Each index summarises a different aspect of the socio-economic conditions in an area. The indexes have been obtained by summarising the information from a variety of underlying social and economic factors, each index using a different set of underlying variables.
The five indexes are:
- Urban Index of Relative Socio-Economic Advantage
- Rural Index of Relative Socio-Economic Advantage
- Index of Relative Socio-Economic Disadvantage
- Index of Economic Resources
- Index of Education and Occupation
Q: Can I interpret low scores on the Indexes of Advantage as indicators of disadvantage?
A: No. It is important to remember that different variables are used in the construction of each index. It is recommended that you use the Indexes of Advantage as indicators of advantaged status only, and the Index of Relative Socio-Economic Disadvantage as an indicator of disadvantage status.
Q: How can I compare the index scores for different areas?
A: Different areas can be ranked according to the value of their scores: a higher score will indicate an area of relative socio-economic advantage.
However, you need to be careful in interpreting the results, because the indexes are 'original measures' and not 'interval measures'. That is, using the indexes to order the Collection Districts (CD) will provide a meaningful result whereas using other arithmetic relationships between index values will not. For example, a CD with an index value of 1200 does not have twice the well-being of a CD with an index value of 600.
Similarly, the socio-economic difference between two CDs with index values of 800 and 900, in not necessarily the same as the difference between two CDs with index values of 1050 and 1150.
Q: Can I compare the 1996 index values with those obtained from the 1991 product?
A: It is important that the index scores from the 1996 Census are not compared directly to the indexes based on the 1991 Census. For each census year the index values for CDs are standardised to have a mean of 1000 across Australia. This means that the difference between the scores of an area in 1991 and 1996 does not represent the change of socio-economic conditions in the area.
Boundaries of CDs in some areas have changed between censuses. The number of CDs in Australia increased from 31,401 in 1991 to 34,500 in 1996. Consequently, the boundaries of the higher geographic areas such as Statistics Local Area an Local Government Area may not be comparable.
Furthermore, some of the occupation variables in the 1996 indexes are different from those used in the 1991 indexes. This is because the occupation variables are based on the Australian Standard Classification of Occupations (ASCO) which was revised between the 1991 and 1996 Censuses. In addition, some of the variables involving income have used different income cut-offs, as the income ranges collected in the census changed in 1996 from what they were in 1991.
For further information on SEIFA96, including more answers to your questions, click here.
This page first published 20 October 1999, last updated 21 May 2007