The Western debt-based fiat economy will die because it is funding interest payments on old borrowing with new borrowing and interest rates MUST rise (because for example zero and negative interest rates have bankrupted pensions), which will displace funding for other government services. Also eventually the governments will have to cut off all debt that is escaping to cash, gold, or cryptocurrencies. As the stampede accelerates it will by synergistic with the collapse in PUBLIC CONFIDENCE in Western governments and fiat.
Note this will not be hyperinflation because governments will not print more money to hand out to people who want to escape fiat, but instead will be capital controls, confiscation of wealth, and deflationary collapse in totalitarianism. That is why governments are trying to eliminate cash (and they know they can shut down the gold dealers when they are ready making gold illiquid). China (Asia) will probably offer a fiat that still works after 2020 when the Western fiats have become totalitarian jails. This is why the financial capitols of the world will transfer from London and New York to Singapore and Shanghai respectively by 2033 (2032.95).
And if there is a cryptocurrency which is widely used for Internet activities such as how STEEM is used every time we make a post to the blockchain, that cryptocurrency might have a chance of being there right alongside Bitcoin as sustainable because Bitcoin is not the ideal medium-of-exchange due to scaling issues and slow block confirmation period (even 0-confirmation transactions do not confirm in real-time, thus are too slow for comment posts).
RE: Get Ready for a World Currency