This 4th volume of the "University of St. Gallen Series in Law and Economics" contains a transcript of the 4th International Conference on "The Law and Economics of Money and Currency" that was held at Instituto de Ensino e Pesquisa - Insper on June 3, 2011 in São Paulo, Brazil. Organized under the auspices of the Master Program in Law and Economics of the University of St. Gallen and Instituto de Ensino e Pesquisa - Insper, the conference was generously sponsored by the Lemann Foundation. The volume contains contributions of well known lecturers from various countries: Peter Nobel, Heinz Zimmermann, Ulrich Kohli (all from Switzerland), Klaus Löber, Stefan Gerlach, Peter Sester (all from Germany), Juan Jensen, Luciana Yeung, Mário Mesquita, Claudio Haddad (all from Brazil), Gianni de Nicolo (USA) and Sebastian Barnes (France).