Australia’s population clock is, according to the Australian Bureau of Statistics, steadily ticking away at an overall total population increase of one person every 1 minute and 23 seconds.

Many are debating what the ideal population is for a country like Australia. But because most of this population growth is concentrated in our big cities, perhaps we should be thinking less about that and more about the ideal size of a city. Historically, there have been many theories on what this would be.

From Aristotle to Albanese

For Aristotle (384–322 BC), for instance, the key was balance. Cities had to contain a minimum number of groups, such as citizens and slaves, to work politically. Similarly, a city’s population had to be balanced against the size of the territory it drew its resources from to enable each citizen (but not slave) to have what he called a “good life”.

Aristotle reputedly drew on the constitutions of what were then known as city states. These aren’t directly comparable to today’s cities but do make for good test cases with which to examine urban models. City states of the time, in the vanguard of urban life as they were, were equivalent to small towns of today and less connected and more homogeneous.

During the 20th century, as the world’s population grew, planners around the world tried to deliberately limit the size of cities. But how did they decide on the ideal size?

Planning theorist Lewis Keeble wrote in the late 1950s that the ideal UK city size could be determined by setting the distance for citizens to reach the countryside. So, a resident in the centre of a town could reasonably be expected to walk to the edge of the city for a distance of two miles (3.2km).

In the lead-up to the 2016 federal election, Prime Minister Malcolm Turnbull aimed for a deal to be struck between all levels of government, to deliver suburbs where residents can get to school or work within 30 minutes. And in a speech to the National Press Club two years earlier, Labor’s shadow minister for cities, Anthony Albanese, said he was “particularly attracted” to the concept of the 30-minute city.

It’s not the size that matters

But a city’s liveability isn’t equal to its appeal for living and working in. Tokyo, the largest city in the world, will never top the liveability scale. Its infrastructure challenges are of a different order compared to Australia’s cities. The equivalent of Australia’s population passes through the ticket barriers of Shinjuku, its busiest station, in a week.

 

Under this concept, with a density of 50 people per hectare, the ideal city size would be 160,000. For a city, where the population would have access to public transport, Keeble estimated this would be around 4 million.

Keeble was the first to admit these calculations were naive. Yet a calculation of city size based on the biological limits of the human body, mixed with the use of public transport, echoes contemporary thinking. Cities that often top the liveability scale – such as Melbourne and Vancouver – are universally mid-sized (around 4-5 million people) with low population density.

More recently, in the late 1990s, the Italian physicist Cesare Marchetti’s term “the 30-minute city”, first proposed in a relatively obscure paper, has been drawn into policy language.

But these challenges are being managed quite successfully.

Originally Published by The Conversation, continue reading here.