金融危机后“长期停滞”假说的提出与争论

Secular Stagnation in the Post-Crisis Era

2008 年金融危机爆发后,全球经济复苏之缓、之难都远超预期。在此背景下,美国前财政部长萨默斯重提“长期停滞”假说。在“长期停滞”假说中,均衡实际利率为负是核心,总需求不足是症结,财政刺激政策是药方。对于此番经济表现出的长期疲弱,学术界还有许多不同观点,如:超级债务周期、全球储蓄过剩、流动性陷阱等,争论的焦点主要集中于对原因的总结、对债务问题的认识以及对未来均衡实际利率走势的判断上。本文的一大目标就是梳理当前有关的学术争论:争论什么,为何争论,有何依据?厘清这些问题可为下一步凝聚共识、政策协调奠定基础。

Against the backdrop of slower- and harder-than-expected global economic recovery in the wake of the 2008 global financial crisis, former US Secretary of Treasury Larry Summers re-proposed the hypothesis of secular stagnation. The hypothesis is characterized by negative natural interest rate, with the problem ascribed to the demand side, and the solution goes for fiscal stimulus. As for the prolonged sluggish economic performance, the academic circle has come with many other views, like debt super-cycle, global saving glut and liquidity trap, with disagreements mainly focused on the cause of the recession, the perceptions of debt and estimation of future interest rates. This article aims to summarize the related debates, i.e., what the debates are about and why researchers have failed to reach an agreement. The clarification of those debates can lay a foundation for future consensus and policy coordination.