Mapping social diversity in Google Fusion

The concept of relative socio-economic advantage or disadvantage is neither simple, nor well defined. Australian Bureau of Statistics attempts to quantify socio-economic diversity for geographic locations with a suite of four summary measures called Socio-Economic Indexes for Areas (SEIFA).

The four indexes in SEIFA 2006 are:

Index of Relative Socio-economic Disadvantage: is derived from Census variables related to disadvantage, such as low income, low educational attainment, unemployment, and dwellings without motor vehicles.

Index of Relative Socio-economic Advantage and Disadvantage: a continuum of advantage (high values) to disadvantage (low values) which is derived from Census variables related to both advantage and disadvantage, like household with low income and people with a tertiary education.

Index of Economic Resources: focuses on Census variables like the income, housing expenditure and assets of households.

Index of Education and Occupation: includes Census variables relating to the educational and occupational characteristics of communities, like the proportion of people with a higher qualification or those employed in a skilled occupation.

While SEIFA score represents an average of all people living in an area, SEIFA does not represent the individual situation of each person. Larger areas are more likely to have greater diversity of people and households.

A SEIFA score is created using information about people and households in a particular area. This score is standardised against a mean of 1000 with a standard deviation of 100. This means that the average SEIFA score will be 1000 and the middle two-thirds of SEIFA scores will fall between 900 and 1100 (approximately).

To determine the SEIFA rank, all the areas are ordered from lowest score to highest score. The area with the lowest score is given a rank of 1, the area with the second-lowest score is given a rank of 2 and so on, up to the area with the highest score which is given the highest rank, being 2615 for a postal areas (POA) index.

Deciles divide a distribution into ten equal groups. In the case of SEIFA, the distribution of scores is divided into ten equal groups. The lowest scoring 10% of areas are given a decile number of 1, the second-lowest 10% of areas are given a decile number of 2 and so on, up to the highest 10% of areas which are given a decile number of 10.

For more information about SEIFA and its potential uses please refer to the following document: 2039.0 – Information Paper: An Introduction to Socio-Economic Indexes for Areas (SEIFA), 2006

Data tables and maps are available for reference and further reuse via Google’s Fusion Tables:

SEIFA 2006 for NSW Index of Disadvantage
SEIFA 2006 for NSW Advantage-Disadvantage
SEIFA 2006 for NSW Economic Resources
SEIFA 2006 for NSW Education-Occupation
SEIFA for Postal Areas Census 2006 (data table)
Postal Areas NSW Census 2006 Edition (postal area boundaries)


The NSW Interactive Atlas

The Atlas of New South Wales is an initiative of the Land and Property Management Authority and it was created with the objective of providing detailed statistics across a range of topics to educational institutions and the broader community. It is built with Bing Map so, provides very familiar to many, simple and intuitive interface to government information.

All the information is presented as a series of thematic map overlays in four categories:

  • People (eg. population, health, housing, religion, indigenous population, indexes of relative advantage/disadvantage, crime);
  • Economy (eg. labour force, taxation and revenue, and production of fruit and vegetables, oils and grins, and livestock);
  • History (eg. information on settlement, State elections and boarders); and
  • Environment (including vegetation, geology and soils, and locations of national parks).

Users have a choice between satellite image or roads map as a base layer and can adjust transparency level of thematic overlays. Each overlay is accompanied by a comprehensive legend, explaining the meaning of presented data. A click on individual region brings up a pop-up window with information about the region, presented as charts and gauges.

The Atlas of New South Wales is quite responsive considering the amount of data that is required to present thematic overlays. It would benefit though from a bit more legible charts and access to source data in a tabular format and/ or for download. Overall, the application is well built and very simple to navigate through.

Maps and investment

There is an old adage that the three most important rules for selecting a property for purchase are: location, location, location. So, maps should be one of the primary tools in making the purchase decision. With the advent of Google Maps, Bing Maps and plethora of other online mapping applications, all real estate portals integrated mapping based search options into their websites. However, mapping applications presenting analytical information on the state of the property market in various parts of the country are only starting to be brought to life.

Property Investment Map on is the first analytical map released by the major Australian real estate portal. It contains a set of thematic overlays presenting information on gross rental yields, capital gains, vendor discounts and top performing areas – by suburb, for the entire Australia (excluding ACT). Information is available separately for houses and units, as 1 year or 5 year trend measures.

Property Investment Map provides invaluable insights into the dynamics of the property market on a local scale. For example, using the map investors can pinpoint suburbs with good rental yields and capital growth prospects. These areas are the most desirable for investors as high rental yields imply attractiveness of the location to renters as well as availability of properties at prices still offering good value. At the same time, high capital gains yields over short as well as longer term imply consistency in appreciation of properties in a given area over time. Eastlakes in central Sydney is one suburb displaying such characteristics in relation to units -median price increased 17% in 2010 and further rise of 3% is predicted for 2011.

Totally different market dynamics can be demonstrated on example of Rozelle, a suburb just west of the CBD. Despite showing high gross rental yield for units in the last year, it has relatively low rates of capital gains over one as well as 5 year period. It could imply this suburb was overpriced in the past and only now rental yields for units have increased to the level that makes them attractive again for investment purposes (median price dropped 4% in 2010 and prediction for 2011 is 0% growth). If history is to repeat, there is a good chance prices could overshoot again if Rozelle is suddenly “rediscovered” by investors. Property Investment Map cannot give all the answers so, the picture would have to be validated with local knowledge before making any decisions.

Property Investment Map should be in the toolbox of not only investors but also anyone serious about purchasing a property. The only limitation of the map is lack of details on how the information was derived (eg. methodology for data range determination). It is a good starting point for deciding on alternative locations for investment, although it would also be nice to have a numerical version of the dataset available for more detailed comparisons.