I'm watching my USD/JPY trades and thinking about the last 15 years of Japan's economic history. The Japanese went through a similar issue to what we experienced here in the US in 2008, back in the early 90s. Their crash was followed by what is affectionately know as the lost decade. Interest rates were pushed as low as they could go, and still no growth (as measured by inflation). After years of little to no price increases, prices started falling as consumers put-off spending and deflation set in leaving Japan in a Keynesian liquidity trap.
We're not there yet, but we could actually see the economic situation in the US go a similar route but for one thing. Foreign migrants and non-restrictive immigration policies can be the catalyst that can jump-start real long-term economic growth. Japan didn't think so, and restricted migrant access to the country and made it very difficult for them to get jobs. As a result, there was no outside stimulus to population growth coupled with one of the lowest birthrates in the world, Japan went from second largest economy in the world to a far third behind China and being forced to competitively devalue its currency just to spur exports. It only has to do this because there isn't much new internal demands from the quickly retiring Japanese workforce.