Interesting. In my opinion, what you're describing in Japan is the combination of demographics and economics that were all in their favour throughout the 60s, 70s, and 80s. Throughout that time they were one of the fastest growing countries in the world (pop culture at the time was concerned with Japan overtaking the USA). It was helped by the favourable demographics - lots of young people willing to work hard to make a new coutry for themselves.
During the 90s they had both a banking collapse and their demographics flipped, and so this positive outlook all flipped too.
We in the west went through the same thing in the late 2000s. Our economies and financial systems proved to be built on thin air, and our baby-boomer demographics (which we've known about for my entire life, but have utterly failed to properly plan for) have left us with very skewed population pyramids, same as Japan. As a result, our popular sentiment is now relentlessly negative.
I suppose I'm arguing the other side of the chicken/egg split than you. You're saying (I think) that the right popular mood can effect ecomonic progress. I'm saying the economic progress (or lack thereof) shapes the popular mood.
In reality of course we're both right - its just a question of how much contribution each side makes to the cause and effect at any given time.