This still prices them out of 99.9 per cent of the 440 Sydney suburbs with available data. (About 100 suburbs had insufficient data, possibly because there aren't many one-bedroom units available.) To rent in The Rocks – the priciest location – a minimum wage earner would need to work nearly 22 hours a day, seven days a week. They would only need to work 33 hours a week to rent in the cheapest suburb, Llandilo. But then they would be living 57 kilometres from the city centre. The closest affordable neighbourhood to the city centre is Glenfield, 40 kilometres west of the CBD. A full-time worker earning the average NSW wage of $1492 a week ($39.27 an hour) can afford to spend up to $448 a week on housing. This would allow them to rent a one-bedroom unit in 78 per cent of suburbs. Here's the map for full-time workers earning the average wage.

Pushing the poorest residents to the margins of the city undermines the wellbeing of all residents, for at least five reasons. 1. Diversity is good for cities "You need all sorts of people to run a city. You need people to clean it, to wipe tables, work in banks – all those sorts of occupations," says Peter Phibbs, head of urban and regional planning in the faculty of architecture at the University of Sydney. To rent in The Rocks, a minimum wage earner would need to work nearly 22 hours a day, seven days a week.

Driving single parents, students, artists and other low-income workers out to the fringes can reduce a city's vibrancy and social cohesion, research has shown. 2.Long commutes are bad for traffic and public transport Forcing workers to travel long distances creates a drag on the city's economy and increases the burden on roads and public transport. "If the only way you can run your city is to have people travelling very long distances, that puts pressure on your transport system. It's one of the reasons congestion has increased," professor Phibbs says. "And where you're subsidising the cost of public transport, then the cost of your subsidy goes up."

3.The jobs are where the unemployed are not One 2013 report found that jobseekers couldn't afford to live in any of the 40 Australian regions where they were most likely to find jobs. And low income workers living far from job opportunities are more vulnerable to long-term unemployment. "A lot of people just end up dropping out of the employment market … [which] further widens the gap between the have and have-nots," according to professor Phibbs. 4. It's particularly bad for women

Long commutes also place significant strain on families and limit women's participation in the job market, research shows. This is because women typically have primary responsibility for the care of young children and elderly relatives, so often need to stay close to home. As Fairfax Media has previously reported, the male labour force participation rate in outer-Sydney suburbs is about 25 per cent higher than the female rate. 5. It creates a cycle of disadvantage Disadvantage is compounded in cities where low-income residents are priced out of the interior, which offers better opportunities and more highly-paid jobs, says Dallas Rogers, an urban studies lecturer at the University of Western Sydney. "You push the lower income groups to the edges of the city. Those areas are poorly serviced by public transport. There are fewer jobs out there.

"And then in public discourse we start to blame them for not getting a job. There's a systemic dimension to this, to how we design cities," he says. So what can be done? Dr Rogers suggests governments either raise the minimum wage or consider benchmarking the rent of low-income workers to their wages. "So if you're on minimum wage, your rent would need to be set according to your wage, not the market. Public housing is a good example of that … but we're moving away from that approach," Dr Rogers says. The NSW Greens have proposed to strengthen protection for renters by capping rent increases to inflation, limiting increases to one per year, and banning "no grounds" evictions – for example, when the landlord evicts a tenant so they can significantly raise the rent.