Finance, Forex and Investments

If exchange rate system is using common currency,is it fixed or floating exchange rate system?

If an exchange rate system is using common currency,is it a fixed or floating exchange rate system?Common currency is simply a monetary union/integration whereby the same legal tender is broadly accepted in a region of countries.For example,although the Euro is adopted, U.K retains its British Pound and floats it.Why is it that every article I visit online, says that a common currency system is a fixed exchange rate system?A region may use a common currency but still chooses to float its single country's currency and a central authority may still float the common currency right?

Public Comments

1. Normally we think of a country as having only one system of currency. You describe a situation of two currencies, one of which is common to at least one other country. So the common form of currency is fixed currency (at least between the two countries) and the local currency can be fixed or floating in value relative to this common kind, as the choice of the government so decides. Most writers of articles don't need to mention the full situation in order to make their discussion points. It is not that they are unaware of the more complex situation, they simply choose to assume it, so as to avoid having to go into greater detail.