Now we can see some countries are regulating bitcoin and some government don't like it.Otherwise Bitcoin hasn't a stable price.
So my question is can bitcoin be a main currency of world economy?
If many government regulate bitcoin as payment, i think bitcoin can be international currency. People will use bitcoin for his/her travel because accepted in any merchant and its more secure and save than carrying fiat money. Most merchant afraid accepting bitcoin as payment because government not regulate it yet, and if government regulating bitcoin, i am believe bitcoin very useful