Naya and Morgan [2] suggest that if the trade figures of any two trading partners were accurate, the f.o.b. imports of one country as a ratio of the trading partner's f.o.b. exports to that country should be 1.0 for both countries. This article shows that, even with completely accurate data, the ratio need not be 1.0 if the system of designating import and export trading partners involves imports being recorded by country of production and exports by some asymmetrical method. The analysis has relevance for Naya and Morgan's study on the accuracy of trade statistics of Southeast Asian countries because most of these countries and their trading partners record trade data by such methods.