“By the end of 2024 there will be a Single Global Currency managed by a Global Central Bank within a Global Monetary Union.(3-G's) This currency will be legal tender in countries which comprise at least 51% of the world's GDP.”

The people of the world want their money to be stable and convenient internationally. The creation of the euro and the European Monetary Union have shown how such stability and international convenience, including zero foreign exchange transaction costs, can be achieved. For countries joining a single global currency, there will be no balance or payments problems, nor currency crises. The major problem with the euro is that it is only one of the 147 currencies of the U.N.'s 191 members, and is thus still subject to the same exchange rate fluctuations as the other 146. A single global currency, with more member countries will be more stable and less subject to the whims of the diminishing foreign exchange marketplace. The 3-G's may be achieved by the continued growth of the European Monetary Union, perhaps together with a merger with one or more other regional monetary unions; or an entirely new global monetary union may be created at an international conference. After the 51% milestone is achieved, only a few more years would be required to reach 95%.
Two predictions in LongBets, 77 and 122, relate to this prediction, but those predictions are overly cautious.
This prediction is the goal of the Single Global Currency Association, with website www.singleglobalcurrency.org