> The system where we reduce interest rates to spur spending to stimulate the economy (probably) don’t work when interest rates negative.
Sure it will. We're just in the early stages of the government abusing the Fed & USD for spending expansion, they've yet to begin getting truly outlandish on what could be done. They'll pump up the government spending projects, directly funded (subsidized) by the Fed's policies. It will continue to work at least for a while yet. 30 more years at a minimum, based on what Japan was able to manage (with a weaker currency (ie not the global reserve currency), in a weaker economy, lower incomes, with far less wealth to debase).
Negative rates means you get a 'free' national high-speed rail project. You get 'free' $2 trillion in infrastructure spending. You get 'free' expansion of Medicare down the ladder and Medicaid up the ladder (likely lessens the tax hammer short-term anyway). I mention those things because the next President after Trump is guaranteed to be a Democrat and is guaranteed to pursue some variation of those general things (high-speed rail is questionable, unfortunately). We're likely to enter a window in the next decade, where the US can float a trillion dollars for 30 years at 0.5% or lower. We desperately need to violently take advantage of that small window of opportunity to build a national high-speed rail network and pull off a once-in-a-generation repair of our infrastructure. The voters will support it in that time frame.