Cross-hauling is the practice of trading the same commodity in both directions between two countries. For example, if the U.S. sold cars in Japan in addition to Japanese cars being imported into the U.S., that would be cross-hauling. Trade statistics show that many commodities are cross-hauled. Explain why international trade economists find invalid the argument of U.S. auto makers that, the inability of U.S. auto firms to sell in Japan shows unfair trade practices.