In this paper, I consider a simple model in which agents learn about the inflation target of a central bank over time by observing the policy instrument or inflation outcomes. Measuring credibility as the distance between the perceived target and the actual target, an increase in credibility is beneficial to the central bank because it brings the policy consistent with attaining the inflation target closer to that required to attain the output target.
This paper surveys the literature on the zero bound on the nominal interest rate. It addresses questions ranging from the conditions under which the zero bound on the nominal interest rate might occur to policy options to avoid or use to exit from such a situation. We discuss literature that examines historical and country evidence, and literature that uses models to generate evidence on this question.