I’m okay with letting the Americans use the Canadian dollar, once they make their banking system as stable as ours.
Well in my system, governments can’t simply print money. They can actually run out of it. Increase in the amount of money due to inflation or simple population growth would be tied to an objective standard. It seems the benefits of having a One World Currency (OWC) then would be that one country having a lot of money would not make it worth less. Goods in this hypothetical economy would still be worth the same, just that people would be willing to pay more or less for the same item.
How I see it working using your example is this: Say Greece’s economy tanks and people need to take a pay 1/10th pay cut or 1/10th of the people need to be laid off. They don’t want to do that. In the real world they can increase the money supply. However, in this hypothetical world, they can’t, they only have a finite amount of money to pay people. They can’t print money, and borrowing it has to come from somewhere, so they are forced to either pay less or lay people off. Why couldn’t that work?
Greece today can print more Drachmas, but in the OWC world, they can’t. The extra bills have to come from somewhere, either from borrowing or increasing their exports (or decreasing their imports). Doesn’t that solve one major problem of real world countries inflating their currency?
But the bigger the government, the farther each voice can affect. You’re just looking at one aspect of having a world government. You don’t mention that it is also more democratic for voters in California to affect citizens in South Sudan with their vote. I think the trade off balance itself out, so I have no problems with a world government. People always worry about what others would make them do but they don’t consider that they have the same power
That’s just how most commerce works these days, including retail.
In the real world, there’s a phenomena called Nominal Rigidity. It’s sometimes referred to as “price-stickiness” or “wage-stickiness” or “downward nominal wage rigidity.” The basic idea is that prices and wages are resistant to nominal changes downward. Nominal here means the amount expressed in units of currency. Basically, if employees are being paid $10/hr, it seems to be very difficult to move them to $9/hr. It’s just something that happens, it’s been observed over and over again, and there are a number of theories as to why it happens.
Which is why if the economy actually needs people to move from $10/hr to $9/hr, the easiest way to do that is to inflate the currency and reduce the real value of wages. The same thing is also observed with prices for goods, although with goods, some companies can get around that by reducing the amount of stuff you get for the same price (say, for example, reducing the size of the candy bar but keeping the price the same).
Having a single currency can be emulated, in part, by a country’s tieing its currency to a big currency, e.g. U.S. dollar.
In my opinion, Thailand’s pegging its baht (in effect *) to the U.S. dollar was a key precursor to the วิกฤตต้มยำกุ้ง, the 1997 Thai currency collapse which led to the 1997 financial crisis. To sustain Thailand’s growth it was convenient for them to have high inflation and high interest rates. Pegging the inflating currency to the non-inflating dollar was anomalous. Gullible foreigners, trying to take advantage of high Thai interest rates, helped augment the Thai over-building boom in a vicious cycle.
(* - Thailand had left dollar parity in the mid 1980’s, replacing it with a secret “basket.” The basket wasn’t too secret, however. Simple linear regression of BOT forex quotes demonstrated it to be a 80-10-10 mix of dollar, yen and euro, IIRC.)