A single currency could help facilitate additional trade. Think of the tremendous amount of “trade” by firms that occur in the US from state to state, and a single currency facilitates that trade. However, it is true that countries would not be able to manipulate their currencies to alter the terms of trade. They would have to compete, just like firms across states within the US, on all the other competitive dimensions, including government/state enticements.
Let me also take some of the logistics out of the equation. Just like current central bank arrangements, the production of the GLOBALL would come from one global central bank. You can view this GLOBALL CENTRAL BANK as the central bank of central bankers. By the way, this central bank essentially already exists — it’s called the BIS The GLOBALL would be fiat money.
That is, like the dollar, Euro, yen…, it is paper currency (or can even be done in digital form; who knows maybe even like the highly volatile Bitcoin (but just the underlying technology here, see the attached article) made legal tender by decree and not backed by a commodity. Its value, essentially again like the dollar, would be determined by its limited supply.
Just imagine all the global efficiency – it could make global transactions and travel as “easy” as those that currently occur from state to state within the US or more recently from country to country within Europe under the Euro – though the Euro has had its difficulties, including deficit/debt divergent challenges.
What do you think – should we just go ahead and go with the GLOBALL? If the GLOBALL were in fact the dollar, does this change your perspective?