If the world uses a single currency, will the economy be more stable?
This is a very interesting question. The sovereign nations issue their own currencies and are taken for granted by many people, but few consider whether this is the economically optimal option.
There will be chaos if that happens along with different governments around the world, if someone wants to implement that kind of system i think leaders all over the world should make an agreement about this because if not it will not be implemented forever because of different economy on every countries.