The Australian Financial Review ran an article on the weekend by Deirdre Macken that perpetuates the myth that Melbourne and Sydney are archetypal sprawled cities (Shifting sands of suburbia – gated unfortunately). The article claims that Melbourne’s population density is 520 persons per km2 and Sydney’s is 370 persons per km2. Melbourne denser than Sydney? That should have set off a few bells.

The problem is the journalist used population figures from a new Australian Bureau of Statistics publication, Regional population growth, Australia, 2008-09, released on 30 March 2010. Rather than use the urbanised or developed part of the metropolitan area to calculate population density, the ABS uses the Melbourne Statistical Division (MSD) as the boundary. This is a patently unsuitable definition for this purpose because it includes some very large undeveloped areas. As I’ve noted before, the MSD boundary extends to Warburton in the east!

The fact is the population density of the built-up area of Melbourne is around 1,600 persons per km2, nothing like the cited figure of 520 persons per km2. Melbourne is actually a relatively dense city. As I’ve also observed before (here and here), there are only a handful of cities in the US of comparable or larger size that have a higher average density: Los Angeles, San Francisco, New York and Miami. Melbourne is denser than such cities as Boston, Seattle, Detroit and Philadelphia, to name just a few.

Sydney’s average density is around 2,100 persons per km2, about the same as the urbanised area of New York. Sydney doesn’t have a core like Manhattan but neither does it have the extensive low density fringe development that surrounds outer New York.

I have sympathy with the journalist who relied, quite reasonably, on the calculations of the ABS. Why should a working journalist need to question statistics produced by the Australian Bureau of Statistics? Really, the ABS needs to take a more responsible approach to the way it estimates population density.

The article nevertheless also earned my ire because it implied that most growth is taking place in the more densely populated inner areas of our major cities:

“….when people head for the city they are increasingly settling in the inner suburbs that are already densely populated. The ABS report found that the biggest increases in density last year were recorded in those suburbs that already had the most people living in close quarters”

The same ABS report shows that while inner city Melbourne did grow faster than other parts of the metropolitan area, it captured just 8% of total growth from 2008 to 2009 whereas the outer suburbs picked up 56%. Moreover, when looked at over the longer period from 2001 to 2009, the inner city’s share of total growth was 13%, indicating that it went off the boil in the most recent year.

It is vital in preparing for possibly unprecedented population growth that key media institutions like the Australian Financial Review have a sound baseline understanding of how our existing major cities operate. It is just as important that the ABS presents data in a way that is relevant and useful for policy analysis and debate.