Where is Melbourne’s ‘centre of gravity’ ?

Change in the 'centre of mass' of employment in Melbourne, 1981-2006

We’re familiar enough with the idea of the ‘centre of gravity’ of population in Melbourne. But where is the centre of gravity of employment?

Is it the city centre? No, for one thing the CBD’s only got around 15% of all metropolitan jobs. For another, the combination of Melbourne’s distinctly lop-sided growth south of the Yarra and the fact that 72% of jobs are more than 5 km from the CBD, suggests it’s going to be somewhere south east of the CBD.

So I’ve calculated the location of the centre of gravity (more correctly, the ‘centre of mass’) of jobs from Census data. The accompanying chart shows how that location changed over the period from 1981 to 2006.

The centre of gravity is calculated by dividing Melbourne up into 1,000 traffic zones and weighting the coordinates of the centroid of each zone by the number of jobs it holds. If you imagine a relief model of employment in Melbourne, the centre of gravity is where you’d rest the model on a needle so that it balancess perfectly.

In 1981, the centre of mass of employment was 5.9 km east south east of the CBD, on Kooyong Rd, just north of Toorak Rd. By 2006 it was 7.9 km from the CBD, close to the corner of Malvern and Tooronga Rds.

This movement reflected the much stronger growth in jobs in the suburbs over this period compared to the CBD and inner city. Read the rest of this entry »

Are the suburbs dormitories?

"Centre of gravity" of jobs, 1981 and 2006

There are many misconceptions about the suburbs. A common one is that they are dormitories for workers who commute to the CBD. Another is that jobs in the suburbs are mostly low skill and low pay.

The reality is most economic activity in our capital cities takes place in the suburbs. In Melbourne, for example, 72% of jobs are more than 5 km from the CBD, 50% are more than 13 km away and 25% more than 22 km away.

Jobs have been moving away from the centre for a long time. The “centre of gravity” of jobs in Melbourne is now 7.9 km south east of the CBD, in the vicinity of Tooronga station, East Malvern. That’s up from 5.9 km in 1981. The “average”  job is 15.6 km from the CBD (12.4 km in 1981).

This decentralised pattern holds for most industry sectors. More than 70% of jobs in the Community sector and more than 80% of jobs in the Retail, Wholesale and Manufacturing sectors are in the suburbs (defined as more than 5km from the CBD). Even in the Commercial Services sector, which is the inner city’s great strength, 49% of metropolitan jobs are in the suburbs.

Over 90% of Melburnites live in the suburbs and the great bulk work there too. Less than 10% of workers who live in outer suburbs like Casey, Cardinia, Dandenong, Knox, Maroondah, Mornington work in the centre (City of Melbourne). Even in older suburbs like Hobsons Bay, Brimbank, Maribyrnong and Moonee Valley, less than 25% of the workforce works in the centre. Read the rest of this entry »