美国双缺口、对外债务与经济增长

US Twin Gaps,External Debt and Economic Growth

对外债务显著扩张是当代美国经济外部失衡加剧的主要表现形式,但对外债务扩张的根本原因在于美国经济的内部失衡。对外债务的根本作用在于弥补美国政府部门财政缺口与私人部门储蓄-投资缺口。研究显示,在经济景气阶段,美国私人部门储蓄-投资缺口会扩大,工商企业会增加对外负债弥补储蓄-投资缺口;在经济衰退阶段,美国政府部门财政缺口会扩大,政府部门会增加对外负债弥补财政缺口。因此,无论美国经济景气还是衰退,其对外债务规模都在增加。考虑到美国经济对对外债务的强烈依赖性,我们有理由认为,未来美国的对外债务仍然会持续扩张。

The significant expansion of external debt is the main feature of the external imbalances in the contemporary US economy,but the reason why the external debt expands is the internal imbalance of the US economy.The external debt plays a fundamental role in covering the fiscal gap for the US government and gap in private sector′s savings-investment.Research shows that the gap in US private sector′s savings-investment will expand in the economic boom,and businesses will increase the external liabilities to compensate for the savings-investment gap;in the recessionary period,fiscal gap will expand,and the US government will also increase the external liabilities to make up this fiscal gap.Therefore,no matter whether the US economy in the boom or recession,its external debt keeps increasing.Because the US economy strongly dependent on its external debt,it is reasonable to believe that US external debt will continue expanding in the future.