Practice can be seen by the many cultural shifts we had which had zero to do with population growth / housing shortages, but still increased prices tremendously. Higher loans, longer mortgages and lower interest rates, for one. Increased dual incomes is another.
This combined with climate change and it's ability to change the landscape (literally) makes it getting harder to predict where people might actually want to live.
For example, I visited Scottsdale, Arizona not long ago which is going through it's own mini-boom at the moment. Will that be a nice place to live in ten years with rising temps? One would have to ask the question? Would people still pay huge money to live in Tahoe with poor snow quality and lots of bush fires in summer?
You did say there's too many variables :)
So if China's population starts to crash or their economy goes bad at some stage what effect will this then have on the Australian market (for example)?
I'm guessing not much because the inflationary property price damage has been done. It's a curious thought.
Also in the case for "steady populations with little growth", wouldn't this mean that property prices will also stabilize and eventually drop? This stabilized property market will be interesting because people won't be able to make the huge capital gains and returns they were used too? A lot of property investors are also probably pretty heavily indebted and so any type of economic trouble might put many in a precarious position.