Some differences between countries will always exist so as long the markets are free to adjust to the changing of the economic conditions, country differentials should largely be of a transitory nature. The Monetary Union challenges the whole country when is relate it to individual citizens that have to adapt to a whole new monetary reference system. While this take time for older generations, who are used to what is cheap and expensive in the terms o f the old currency; its outstanding how fast the changeover goes to the younger generations. To conclude, a key challenge for all countries in the European Union lies in an open and transparent debate with the general public on the implications of euro are participation and also the necessary steps to the toward goal. Surveys show that there is a diminutive of citizens in the European Union Member States believe that adopting the euro will have a cocksure consequences for their countries. A small portion of people feel happy about the prospect of a future changeover. Sometimes, participation in the Monetary Union is viewed by sceptic in terms of a loss of sovereignty. For instance, its clear that there are some limits to the scope for the national monetary policy to deliver both price and exchange rate stability in a world with free capital movements.
As I mentioned before there are advantage of accepting the euro as a single currency. There also some countries in the European Union that have not adopted the euro. Those countries are England, Norway, Sweden and Switzerland. Some reasons that explain why those countries don't implement the euro as a single currency are: Loss of independent monetary policy and national sovereignty. The deathtrap of losing national sovereignty from the international agreements are similar for nations that have their import control laws overridden by the World Trade Organization treaties. The same thing would happen with the economic decision that demand to be made by the Euro states.