An excerpt of the debate between Martin Höpner (Max Planck Institute for the Study of Societies, Germany) and Emiliano Brancaccio (University of Sannio, Italy) during the seminar “Un Plan B pour l’Europe” that was held in Paris on January 23, 2016. Höpner supports Lafontaine’s proposal to return to the old European Monetary System. Brancaccio states that it is necessary to add controls on international mobility of capital and maybe even goods to and from countries that adopt deflationary policies to increase their external surplus. On this subject see also “Back to the old EMS? A comment on Lafontaine”.