Foreword Lance Liebman; Introduction Henrik Horn and Petros C. Mavroidis; US compliance with WTO rulings on zeroing in anti-dumping: United States – zeroing (EC); United States – zeroing (Japan) Article 21.5 DSU Implementation Reports Bernard Hoekman and Jasper Wauters; United States – continued existence and application of zeroing methodology: the end of zeroing? Thomas J. Prusa and Edwin Vermulst; Incomplete harmonization contracts in international economic law: report of the panel, China – measures affecting the protection and enforcement of intellectual property rights, WT/DS362/R, adopted 20 March 2009 Kamal Saggi and Joel P. Trachtman; Comment Robert Howse; Trading cultures: Appellate Body Report on China – audiovisuals WT/DS363/AB/R, adopted 19 January 2010 Paola Conconi and Joost Pauwelyn; Comment Frieder Roessler; 'Optimal' retaliation in the WTO – a commentary on the upland cotton arbitration Gene M. Grossman and Alan O. Sykes.