The signalling channel of negative interest rates
研究了负利率的一种新信号渠道，证明在时间一致政策和政策平滑偏好下，负利率可有效传递宽松信号，且其效果受政策惯性、准备金水平和零下限持续时间影响。
Negative interest rates remain a controversial policy for central banks. We study a novel signalling channel and ask under what conditions negative rates should exist in an optimal policymaker’s toolkit. We prove two necessary conditions for the opti mality of negative rates: a time-consistent policy setting and a preference for policy smoothing. These conditions allow negative rates to signal policy easing, even with deposit rates constrained at zero. In an estimated model, the signalling channel dominates the costly interest margin channel. However, the effectiveness of negative rates depends sensitively on the degree of policy inertia, level of reserves, and ZLB duration.