Abstract: This paper reviews the WTO Appellate Body Reports on United States–Zeroing (EC) (Article 21.5 DSU – EC) (WT/DS294/AB/RW, 14 May 2009) and United States–Zeroing (Japan) (Article 21.5 DSU – Japan) (WT/DS322/AB/RW, 18 August 2009). The Appellate Body found that the United States had not brought its anti-dumping measures into compliance with the WTO Anti-Dumping Agreement as it continued to use zeroing in annual reviews of anti-dumping orders. We argue that this conclusion – based on a complicated discussion of what constitutes a ‘measure taken to comply’ – could have been reached through a much simpler and direct argument. Continued noncompliance by the United States generates costs to traders targeting the United States and the trading system more generally. We argue that from a broader WTO compliance perspective consideration should be given to stronger multilateral surveillance of anti-dumping practice by all WTO members and to more analysis and effective communication by economists regarding the costs of zeroing and anti-dumping practices more generally.