My first thought was that negative interest rates would drive money from banks into the stock market, equities being the only means of capital appreciation. I don’t see any disaster there.
In the case of Japan, where corporations buy each other’s stocks, a phenomenon known as keiretsu, selling these stocks is sort of insulting to the boards of the companies being sold. As a result there aren’t that many stocks to buy and the markets are extremely volatile. Japan makes for a hard case study.
Perversely, it seems negative rates, per the article, have boosted savings, not driven spending. Worried about making it through retirement, people of a certain age began to spend less, not more. The demographics would be important here as an aging society might be bad grounds for negative interest rates, but a youthful one might be just right.
Their remaining options are limited and not very good. They include: default, (hyper)inflation, devaluation of the currency, or crushing tax increases.
I`d drive me to use Mason Jars and midnight holes in the back yard. P!ss on the banks.