The countries that have adopted the euro currency now have a single central bank (the ECB) that sets a common policy interest rate across all of these countries. Explain why a common fiscal authority will ultimately also be required for the euro to be a success in the long term. Use for example Germany is booming and Greece is going to a recession. In that case, there is no way that monetary country can target both simultaneously and the only solution to this problem is the establishment of a common Fiscal Authority.