Defence date: 13 February 2014Examining Board: Professor Arpad Abraham, EUI; Professor Piero Gottardi, Supervisor, EUI; Professor Timothy J. Kehoe, University of Minnesota; Professor Franck Portier, Toulouse School of Economics.First made available online on 16 May 2014.This thesis contributes to two traditional debates in quantitative macroeconomics: (i) the welfare costs of aggregate shocks and (ii) the role of financial integration for international business cycle co-movement and risk-sharing. In recent years both debates regained attention, in particular after the experience of the recent U.S. financial crisis and the subsequent international recession. The first chapter of this thesis, joint work with Tommaso Oliviero, investigates the...