From its very beginning, the Euro area has been characterized by manifold economic heterogeneity, and the recent economic crisis highlights the central role that economic heterogeneity can play, especially when it comes to the transmission of unconventional monetary policy. Therefore, this year's spring conference, which is jointly organized by the Banque de France and the Deutsche Bundesbank, is dedicated to research on heterogeneity in the euro area and on unconventional monetary policy.