Have We Underestimated the Likelihood and Severity of Zero Lower Bound Events?
发现此前研究因忽略模型参数不确定性、过度关注大缓和时期以及依赖无法产生持续零利率下限的结构模型，低估了零利率下限对央行的威胁，并指出美联储资产购买虽改善经济但未阻止其负面影响。
Prior to the financial crisis, most economists probably did not view the zero lower bound (ZLB) as a major problem for central banks. Using a range of structural and statistical models, we find that previous research understated the ZLB threat by ignoring uncertainty about model parameters and latent variables, focusing too much on the Great Moderation experience, and relying on structural models whose dynamics cannot generate sustained ZLB episodes. Our analysis also suggests that the Federal Reserve's asset purchases, while materially improving macroeconomic conditions, did not prevent the ZLB constraint from having first‐order adverse effects on real activity and inflation.