What would happen if all currencies had the same value?
Such situation can become real only if the currency has some real value like gold. The rules for the monetary policy will have to be more rigid for all countries. There will be a necessity to create one organization which will control the flow of the world currency as well as its value. However, it’s quite impossible that this all will be done in a friendly way. Sometimes the government cannot resolve monetary problems within one small country. What can be triggered if the whole world is involved? There is a high likelihood that new conflicts and even wars can be brought about.
From my perspective, the attempts to create the world currency is doomed to failure, just as it happened with the attempt to create the world language Esperanto.