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.
If will depend upon the nation who has the most feasible goods like food and technology. If world has one currency then all nations shall develop well their products so that they could earn and keep the highest percentage of the words money. Pity for those nations who have no feasible commodities because they would less their bargains to trade so i say still the poor will exist even if the currency is just one.