The pseudo-Keynesians are obsessed with M2, the money velocity, because they want inflation, because that's how socialist spending on welfare, and "stimulus" can survive deficits and the debt, instead of paying it down, they just want to shrink their liabilities.
And Quantitative Easing/printing money doesn't drive inflation and the "brick and mortar" (cough) "recovery" unless that money is pushed out onto the street and end-users/consumers/businesses are forced to spend it or lose it to negative interest rates. Because of the crappy non-recovery in real jobs and brick-n-mortar investment, the low-no interest rate money has all just gone into savings or securities and other paper-wealth with institutional savers and investors.
And it all comes back round to the Fed, and the other nation's central banks being constantly used as a throttle/brake on the economy, instead of just sticking to what they should *expletive deleted*ing be doing, which is trying to maintain the stability of the currency, and let the damn economy sort itself out as it sees fit.
Like every other Lefty/Socialist idea, when everyone does not comply with what they try to dictate, because basic human nature and enlightened self-interest is against most forced collectivist solutions, the stick comes out to get compliance. So they shake the money out of the banks with negative interest rates. And the second step is to try and restrict other value stores like precious metals, or cash.
This.
Basically, the central money planners are running out of knobs to turn (while forgetting that the knobs they do turn have inflection points--a little stimulus, good...more, not so much, a little monetary tweak, good, a lot, not so much)
Fiscal stimulus (2009)--no result
MASSIVE monetary stimulus (QE1,2,infinity)--no result
Now we are at the point where we have massively increased the money supply, which would normally cause massive inflation (by definition, money supply growing more than nominal GDP = inflation), but we haven't since the velocity has cratered. So the "push for 'nominal' inflation" that would normally cause some level of real investment and economic quasi-growth has stalled.
The last real knob is to penalize banks for holding substantive reserves / penalize savers for not spending (demand side economics), but since ZIRP is, well, zero, the only way to turn the knob is to negative.
Since you can't penalize non-soending of a mattress full of cash, or a big block of gold, that leads to the push toward cashless--as then the toll can be paid...otherwise, since negative interest means cash is actually deflationary, it just wouldn't work if you could just pull your accounts and not be affected.
Also, given that current law allows for a "bail-in" of banks HERE...(see Cyprus)...well, ugh.
Also, if they do a NIRP, IMHO, it will rapidly get out of control, as the velocity would spike, meaning the existing huge bulwark of money supply would suddenly hit at "normal" velocities and blammo--inflation.
Which means the "spend everything now" would accelerate, and spiral.
Given the resistance (and inability) of central banks to pull money out of the economy (since no one wants the bullshit they are selling), putting the breaks on would be tough.
It's kind of a perfect storm scenario where a black swan event could really cause issues...
Time to be diversified...