Defence date: 21 November 2015Examining Board: Professor Russell Cooper, Penn State University (Supervisor); Professor Piero Gottardi, EUI; Professor Kalin Nikolov, ECB; Professor Cyril Monnet, University of Bern and Study Center Gerzensee.This thesis investigates the design of appropriate institutions to ensure the good conduct of fiscal and monetary policy. The three chapters develop theoretical frameworks to address the time-inconsistency of policy plans or prevent the occurrence of self-fulfilling prophecies. Time-inconsistency refers to a situation where preferences over policy change over time. Optimal policy plans are not credible, since agents anticipate the implementation of another policy in the future. This issue is particularly ...