The papers in this Symposium issue complement two other compilations of research on the multilateral trading system published in Evenett and Hoekman (2006) and Hoekman and Vines (2007) and are a final output of the UK Department for International Development supported Global Trade and Financial Architecture project. The genesis of this Symposium was a CEPR workshop hosted by the OECD in March 2012 with support from DG Research (grant: PEGGED Collaborative Projects under the EU's Seventh Framework Programme, Contract no. SSH-CT-2008-217559). Draft papers were presented at a conference at the Elliott School of International Affairs, George Washington University, hosted by Michael Moore in April 2013. We are very grateful to Frank van Tongeren at the OECD and Mike Moore at the Elliott School for their support of the meetings, to Michelle Chester and Rebecca Martin at the World Bank for help with logistics, to the participants in both events, especially the discussants, and to Alan Winters and an anonymous referee for comments on the submitted papers.