CIT Sustains Use of Simple Averages in Denominator of 'd' Test

The Court of International Trade on Feb. 12 sustained the Commerce Department's decision to use a simple average of standard deviations in the denominator of Cohens d test for detecting "masked" dumping as part of the antidumping investigation of steel nails from Taiwan. The U.S. Court of Appeals for the Federal Circuit has remanded this decision twice, finding that the academic literature relies on a weighted average. On remand, Commerce said the literature uses a simple average when the sample sizes are equal and that the standard deviation of a full population is "in fact the actual standard deviation." Because the agency used the full population of data in using the Cohen's d test, using a simple average is supported, Judge Claire Kelly said.