美国对外负债的可持续性与国际货币体系的未来

Sustainability of US' Foreign Borrowing and the Future of International Monetary System

要回归到某种形式的固定汇率制度,需要对国际资本流动进行全面且国际性的管制,乃至各国放弃管理货币制度下行使的金融主权。从经济、政治和政策上考虑,这两种要求都无法实现。欧元、日元、人民币甚至把合成货币(SDR)都考虑在内,也难以想像在可以预测的未来(21世纪中叶为止)能够出现替代美元的货币。美国的对外资产和负债之间有正的投资回报差额,这一差额在长期内将一直存在。只要这种回报差额持续存在,并且对外资产和负债占GDP的比率能够按照一定的速度扩大,那么即便美国的贸易收支逆差占GDP的比率维持在4%左右,其对外纯负债占GDP的比重维持稳定状态的可能性也是很大的。因此,以美元为中心的、由多数主要货币构成的现行浮动汇率制度具有很强的可持续性,以至于完全有可能在今后继续存在。

Return to certain form of fixed exchange rate regime requires all-round international regulation of capital movement and the willingness of world economies to give up their financial sovereignty in their management of monetary systems.Considering their economic,political and policy implications,the requirements are not feasible.It is hard to imagine that there will be a currency to replace the dollar in the foreseeable future(by the middle of the 21st century),whether it is euro,yen,yuan or even SDR as a 'mixed currency'.There is a positive investment return gap between US external assets and liabilities and the gap will exist for a long time.So long as there is the gap and the ratio of external assets and liabilities to GDP could expand at certain rate,then even if the ratio of US trade deficit to GDP is maintained at about 4 percent,the possibility is high that its ratio of net external liabilities to GDP will be kept stable.Therefore,the current multi-currency floating exchange rate regime,centered on the dollar,is very sustainable and it is highly possible that it will continue to exist.