But this overlooked a crucial feature of monetary unions: free capital mobility and elimination of currency risk – indispensable attributes of a currency area – could be (and were) the source of asymmetric shocks. Currency unions, in other words, must worry about endogenous as much as exogenous shocks.
但这忽视了货币联盟的一个关键特征：资本自由流动和货币风险的消除——货币区必不可少的属性——可能成为（也确实成为过）不对称冲击的原因。换句话说，货币联盟必须不但要考虑外生冲击，也要考虑内生冲击。