Perhaps we'll be stuck with ZIRP for a bit longer :/
Central planning interest rates will probably never be over 3-4% again (and that's a bullish outlook).
http://data.worldbank.org/indicator/SP.POP.GROW
Also, you're assuming more people = population growth; that's like Snapshat saying they're profitable because they have tons of users, but no revenue. You need a properly functioning economy as well as people to have growth (you need more than that, but that's all I included for simplicity sake).
1. Wealth demography. Wealth is held by older people seeking safety not growth/risk.
2. Capital stagnation. Capital is being stockpiled by central banks and large corporations. The former seeks to rectify structural problems in spending and banking sectors. The latter seeks to avoid tax liability.
3. Small businesses abandoned. Developed nations, the US in particular, have focused resources on the largest institutions and institutions serving the poorest. By comparison small businesses are ignored creating more risk for large institutions, and incrasing the ranks of the poor.
4. Global instability. Declines are almost always preceded by alarming world events causing capital flights that expose imbalances in economies. Yes, the solution is to not have imbalances, but aside from that utopian ideal, restoration of a stable world order opens the door to economic risk taking and then prosperity.
Not until we see a large scale war. Nothing raises interest rates like a bond-funded war campaign. A war would also increase aggregate demand, R&D spend, and decrease the domestic labor force.
It's a sad fact that it takes violence/discomfort to galvanize and restore discipline to a nation and its leaders. Not unlike the disruption of old industries by the new. Except in war, you break bones and bodies whereas in startup land you break laws and customs.
I don't think we want a large scale war. Technology benefited a lot from previous wars - without WWII and the Cold War computing and telecoms would be a few decades behind - but technology has changed the risk/benefit profile to make war unfeasibly destructive.
The irony is there's a lot that could be done. We need clean energy, more support for small businesses of all kinds, desalination, infrastructure replacement, and possibly a hugely increased space program.
But current economic models are fiscally constipated - possibly terminally - and improvements are unlikely until they're replaced.
We should have been doing all that and more. Unfortunately, the only thing that was politically feasible was QE.
> But current economic models are fiscally constipated
Absolutely.
After hearing Mark Blyth's recent "ha ha only serious" summary[1] of both of these points... it's going to be a rough ride.
Given Japan's experience we'll probably have it for at least another decade possibly more.