Detecting Illegal Intercountry Trade of Mercury Using Discrepancies in Mirrored Trade Data

The ongoing international movement to phase out mercury, mainly led by the Minamata Convention on Mercury, raises concerns about illegal intercountry trade, including smuggling. This study aims to detect the existence of illegal intercountry mercury trade under the social mercury phase-out movement, focusing on discrepancies in each country's trade statistics. To analyze the trends by year and country for discrepancies in intercountry mercury trade, an intraclass correlation coefficient (ICC) was applied to the mirrored exports and imports from trade statistics of each country provided by the UN Comtrade. The year-based ICC analysis identified a tendency to reduce the detection of discrepancies in the reported mirrored exports and imports for mercury at the intercountry level under the recent mercury phase-out movement. Through an ICC analysis focusing on exporting and importing countries, the validity of the ICC analysis was verified as a way to detect illegal intercountry trade of mercury. Our analyses detecting the illegal trade of related countries contribute to the effectiveness evaluation and custom capacity building required in the Minamata Convention by offering a data-driven method to enable the effective detection of illegal mercury trade.