As a matter of arithmetic, they measure the gap between domestic savings and investment. 基于数理逻辑，他们对国内储蓄和投资之间的差距进行测量。

　　The euro area is an economy with an ageing population: it should save more than it invests. As a result, it should have a current-account surplus. 欧元区经济还存在人口老龄化问题：这样节省下来的钱应该比投资的钱更多。因此，欧元区应该存在经常账户盈余。

　　America's deficit partly reflects the more attractive investment opportunities available there than elsewhere in the world. 美国的赤字部分反映出美国有着比世界其他国家更具吸引力的投资机遇。

　　Imbalances become more worrying, however, if they are larger than economic fundamentals might suggest or financed by short-term inflows. 如果这些不平衡比基本经济因素所暗示的更加巨大，或是由短期现金流入资助，那么不平衡会变得更加令人担心。

　　The crises in the periphery of the euro zone were reflected in deficits caused by a surfeit of unproductive spending. 在欧元区外围的危机被反映在赤字中，而这些赤字是由非生产性支出过度所导致的。

　　But excess surpluses, too, can have drawbacks. 但是过量的盈余也有缺陷。

　　The IMF reckons that the euro area's aggregate current-account surplus IMF估算现在欧元区的经常账户总计盈余

　　is now stronger than would be justified by structural factors and the business cycle alone. 比结构因素以及商业周期所出具的合理范围还有强劲。

　　Growth in the zone relies too much on that of its largest trading partners, including America; 欧元区内的增长过多的依赖于其最大的一些贸易伙伴，比如美国；

　　worthy investment projects at home—in German infrastructure, say—go unfulfilled. 国内有价值的投资项目—比如，德国基础设施建设—都无法实现。

　　Surpluses also have political consequences outside the bloc. 盈余在欧元区外部也产生了政治后果。

　　President Donald Trump sees Europe as a "foe" because of its bilateral trade surplus with America. 由于欧洲与美国的双边贸易盈余，唐纳德·特朗普总统将欧洲看做是一个“敌人”。

　　He has slapped tariffs on European steel and aluminium, and threatened them on cars; the European Union has retaliated. 他对欧洲钢铁和铝征收关税，并威胁要对汽车征税；欧盟以牙还牙。

　　The two sides are negotiating, but trade tensions are likely to keep simmering. 双方正在谈判，但是贸易紧张似乎一触即发。