So what? People don't spend wealth, by and large; they spend income. And wages are high here too.
??? The only reason anyone cares about "wealth" is what one can buy with it. It's value lies in being stored purchasing power for the future. The numbers are largely meaningless without adjustments for costs of living (which need to include home prices that appear to be 4 times higher in Australia). Australia would still come out far ahead of the US, but a bit less so.
If you know what the future purchasing price disparity between Australia and the US is going to be, then you are in a position to become very wealthy indeed.
The 'current best guess' for this future value is provided by the foreign exchange markets - and so the use of the current exchange rate, and not PPP, is indeed the correct calculation (contrary to Loren's claim).
Of course, these exchange rates are just the amalgamated best guess of the market - they are bound to be wildly wrong. But any other guess is likely to be even worse.
PPP differs from the spot rate precisely because the former attempts to estimate the value of current spending, while the latter attempts to estimate the value of wealth - ie
future spending.
There are a number of reasons why home prices here are (comparatively) so high. One is that Australians are so wealthy. If you took away the bottom half of the US housing market, your median home prices would be high too. Few Australians live in (or are prepared to consider living in) low value housing. We have no shortage of land - but we all want to live on the best bits, and most of us can afford to.
There are other considerations - political tools like negative gearing, which could disappear at the stroke of a pen; And the opening up of new desirable real estate by the building of infrastructure that makes formerly undesirable locations more liveable.
There's no physical law that says that Australian homes will remain expensive into the future, in comparison with American or European homes.
But a house in Sydney is still a good investment (if you have the money to take advantage of it).