Understanding Persistent ZLB: Theory and Assessment

We develop a theoretical framework that rationalizes two hypotheses of long-lasting low-interest rate episodes: deflationary-expectations-traps and secular stagnation in a unified setting. These hypotheses differ in the sign of the theoretical correlation between inflation and output growth that they imply. Using the data from Japan over 1998:I–2019:IV, we find that the data favor the expectations-trap hypothesis. The superior model fit of the expectations trap relies on its ability to generate the observed negative correlation between inflation and output growth. (JEL E12, E31, E32, E43, E52)