Economic strategists at Goldman Sachs have said that the European Central Bank has an "inherent problem" enforcing policy coordination among member states - and have proposed a new system that will make it more expensive for countries that behave in a fiscally irresponsible manner to borrow from the central bank.

European countries, particularly Greece, tipped the financial world into a crisis in May as concerns over their ability to repay their debts spilled over into the capital markets.