贬值常常被各国用来改善其经常项目。因为经常项目等于本国储蓄减去国内投资，所以只有当投资下降、储蓄上升或两者同时发生时这种改善才可能实现。那么。贬值究竟如何影响一国的储蓄和投资呢? Devaluation is often used by countries to improve their current accounts．Since the current account equals national saying less domestic investment，however，this improvement can occur only if investment falls，saving rises，or both．How might devaluation affect．national saving and domestic investment?