WTO Zeroing Dispute

When the U.S. Department of Commerce calculates a weighted average dumping margin for a given company, it typically takes into account numerous comparisons between sales in the United States and sales in the home market or third-country market (or costs in the home market).  It is not uncommon for the Commerce Department to find that some comparisons reveal dumping ( e.g., the price in the United States is lower than the home market price), while others reveal no dumping (e.g., the price in the United States is higher than the home market price).  Where a comparison reveals no dumping, Commerce assigns a zero to that comparison, rather than a negative number equal to the amount by which the U.S. price exceeds the home market price.  This practice is commonly referred to as "zeroing."
 
In this dispute, Mexico challenged the use of "zeroing" in both the investigation phase and in assessment proceedings (the proceedings in which authorities determine the actual amount of antidumping duties owed).
 
- Contributed by Vaibhav Agarwal