The recent financial crisis led central banks to lower their interest rates in order to stimulate the economy until they hit the zero lower bound. How should one identify monetary policy shocks in unconventional times? Are unconventional monetary policies as effective as conventional ones? And has the monetary policy transmission mechanism changed in the zero lower bound era? This article aims to provide an overview of the econometric challenges of and the solutions to the identification of monetary policy shocks in unconventional times as well as a survey of their empirical effects on the economy.

中文翻译：

---

识别和评估非常规货币政策的影响：如何做到这一点以及我们学到了什么？

最近的金融危机导致中央银行降低利率以刺激经济，直到达到零下限。人们应该如何识别非常规时期的货币政策冲击？非常规货币政策是否与常规货币政策一样有效？在零下限时代，货币政策的传导机制是否发生了变化？本文旨在概述非常规时期货币政策冲击的计量经济学挑战和解决方案，以及对其对经济的实证影响的调查。