Illustration: John Spooner But what is it that's holding our prices so high? For the full explanation of Australian exceptionalism I'm relying on a typically thorough report by one of our top business economists, Saul Eslake, of Bank of America Merrill Lynch. Much of the explanation comes from the insights of economic geography, the study of how we're affected by the spatial dimension of the economy and, in particular, of the way big cities work. Eslake says foreigners tend to think of Australia as a country of wide-open spaces – "a land of sweeping plains" – where people live with kangaroos grazing peacefully on their front lawns. In truth, most of us live on the edge of the continent, crammed into a few very big cities, making us one of the most urbanised countries on the planet. Almost 60 per cent of Australians live in cities with populations of more than one million, a proportion exceeded only by Japan, Hong Kong and Singapore. Of our six state capitals, all but Hobart fit that description.

Urban geography research suggests real estate prices are usually a lot higher in cities with populations of more than a million. So an unusually high proportion of Australians live in big cities where house prices are safe to be higher. Second, compared with cities in other countries, Australian cities are large in terms of area, relative to the size of their populations. Trouble is, Eslake says, public transport and arterial roads in the outer suburbs of Australian cities are generally inadequate for the task of moving large numbers of people from those suburbs to the central business district. But, because of this, many Australians choose to spend a higher proportion of their incomes on housing so as to spend a smaller proportion of their time commuting. In the process, we bid up the prices of houses and units closer in. So houses prices are higher In Australia partly because commuting times are so long. The recent return of the delusion that building more expressways will reduce traffic congestion is unlikely to make things better. Third, Australian house and apartment prices are higher because our homes tend to be bigger than those in other countries. Three-quarters of us live in detached houses, a much higher proportion than in most other rich countries. Our average size of a new house –206 square metres – is a fraction higher than America's – with daylight third. And our housing is usually constructed using more expensive materials.

The international comparisons purporting to show how expensive our houses are never allow for differences in size and quality. If our housing is of higher quality than other people's, you'd expect it to cost more. Eslake's fourth point is that, thanks partly to the resources boom and two decades without a severe recession, Australians are richer than we were, even relative to other high-income countries. Guess what? Better-off people tend to devote a higher proportion of their income to their housing. We can afford to, so we do. Sounds pretty Australian to me. Another part of the explanation is that, for more than a decade, we've been building too few houses and units to keep up with the growth in the population. Since the turn of the century we've had relatively fast growth averaging 1.4 per cent a year - with 60 per cent of that coming from immigration. During the 1990s we built 145,000 new dwellings a year, but though the annual increase in the population has doubled since then, our construction of new places has averaged just 150,000 a year. It was estimated that by June 2011 we'd built 284,000 fewer homes than needed to maintain housing patterns the way they were.