A second insight from the case of the eurozone, advanced by the economist Paul de Grauwe, is that currency unions can be prone to self-reinforcing liquidity crises, because some vulnerable parts (Greece, Spain, Portugal, and Italy at various points) lack their own currencies. Until the European Central Bank stepped in last August to become the central bank not just of Germany and France, but also of the distressed peripheral countries, the latter were like emerging-market economies that had borrowed in foreign currency and faced abrupt capital outflows.
关于欧元区危机的第二项洞察——来自经济学家格劳维（Paul de Grauwe）——是货币联盟易受自我加强的流动性危机的冲击，因为脆弱部分（不同时点的希腊、西班牙、葡萄牙和意大利）缺少自己的货币。直到去年8月，欧洲央行才不再仅仅是德国和法国的央行，也成为外围受困国的央行，后者就像是借入外币贷款、面临突发资本外流的新兴市场经济体。经济学家卡尔沃（Guillermo Calvo）和莱因哈特（Carmen Reinhart）称之为“突停”，突停提高了风险溢价，削弱了受冲击国家的财政状况，而这反过来又反过来增加了风险，如此等等，最后造成了向下的恶性循环，自我循环的危机就此产生。