Japan had the same thing happen that we're seeing now in the 1980's -- and never recovered.
- rapidly aging population (senior citizens don't buy anything, don't participate in labor force)
- women with a job have zero incentive to get married or have kids because of many cultural restrictions on married women (historically they lose their job, and husbands are home very late.) They buy their own condos now and stay single.
- consumer companies missed the Internet boom (Apple stole Sony's lunch)
- Japanese are legendary savers, not spenders. (It's considered shameful to not have $100k in the bank at all times.)
- govt is holding trillions in corporate stock and bonds to prop up their capital markets.
EDIT: this thread has some insight. https://news.ycombinator.com/item?id=26171294
Low interest doesn't help if you can just send all that money overseas.
Japan is in demographic decline. The US keeps growing demographically, but it does because of immigration. If the US has less immigration the chances improve that it will stagnate economically like Japan.
I don't know if any of the things I am describing are good or bad. But a lot of our assumptions about how the US economy "always" is are based on 300 years of population growth.
Japan, on the other hand, is an island...
Japan wasn't always thrifty. This was a cultural change induced by the bursting of the bubble.
A generational cultural change could just as easily happen to the USA too.