The commerce authorities of China and the United States on Friday unveiled a report on a statistical discrepancy in merchandise trade, saying the discrepancy's share in bilateral trade is dropping.

The report was based on a study conducted by the China-U.S. Joint Commission on Commerce and Trade (JCCT) in an effort to explain and quantify a discrepancy in official China-U.S. merchandise trade statistics via research of published data for 2008, 2009 and 2010.

The report was signed by both China's Ministry of Commerce (MOC) and the U.S. Department of Commerce.

"The statistical discrepancy's share in bilateral trade is declining continuously," the report said.

The greatest discrepancy in the statistics was in China's exports to the U.S., which accounted for 88 percent of the total discrepancy, the report said.

Major causes of the discrepancy in China's export data include differences in trade moving directly from China to the U.S., the amount of goods shipped via intermediary countries and value added in those countries, as well as conceptual and methodological differences, the report said.

After adjusting the identified factors, the discrepancies for 2008, 2009 and 2010 dropped by 71 percent, 64 percent and 67 percent, respectively, according to the report.

Based on the percentages, the U.S trade deficit with China should be 22 percent, 20 percent and 19 percent lower than indicated by previous data for the three years, according to MOC.

The JCCT was established in 1983 as a platform for China and the U.S to promote trade relations and address issues of mutual concern.