Housing bottoms, Japan comparison
I just realised I had no idea what wages were relative to housing costs in Japan, and I still don't. Japan is repeatedly held up as an example of a place where housing prices fell for 18 years, or something like that and there is little information on what affordability was through that period, which is a huge ommission, imho.
So, I did a quick search. This link has a few Japanese properties. The prices still seem very high by my standards, about $300k for something in the range of 400 sq ft. I still don't know what the average wages are, but $2.5 million for about 1500 sq ft.
A quick search of wages I found if you wanted to teach English in Japan you could expect to be paid from $2700 to $4000/month, so it seems housing is still unaffordable in Japan for many people. I suspect due to over population it will remain unaffordable, but it does also help explain the degree of unaffordability.