Medium‐Term Money Neutrality and the Effective Lower Bound
研究发现，在利率有效下限（ELB）时，中期货币中性的模型容易导致均衡不存在，引发产出急剧收缩（收缩黑洞），反而强化了扩张性货币政策的理由，支持央行暂时超调通胀目标。
Abstract Conventional wisdom suggests that medium‐term money neutrality imposes strong limitations on the effects of monetary policy. The point of this paper is that models with medium‐ and long‐term money neutrality are prone to generate nonexistence of equilibria at the effective lower bound (ELB) on interest rates. Nonexistence is suggestive of sharp output contractions—so‐called contractionary black holes—at the ELB. Paradoxically, the case for expansionary monetary policy at the ELB is even stronger in models that feature near money neutrality. The results highlight the benefits of a monetary policy regime in which the central bank temporarily overshoots its inflation target once confronted by the ELB.