Defence date: 15 November 2012Examining Board: Professor Giancarlo Corsetti,University of Cambridge (External Supervisor) Professor Gianluca Benigno, London School of Economics Professor Russell Cooper, Penn State University Professor Henrik Jensen, University of Copenhagen.This thesis investigates the implications of imbalances within a monetary union. In the first chapter, I study how international financial frictions lead to international imbalances and affect optimal fiscal policy in a two-country, two-good DSGE model of a monetary union. I show that the presence of international imbalances affects the optimal conduct of cooperative fiscal policies when the traded goods are complements. Government expenditures optimally play a cross-...