The last eight columns of Table 2.1

The last eight columns of Table 2.1 contain import (9-12) and expon (13-16) shares for each trading partner in total impons or expons. It is apparent from columns 9 and 13 that the United States relies upon markets outside North America for most of its import supply and export demand, with economywide averages of 81 percent for imports and 79 percent for expons. Thus, the potential for trade diversion by the United States in response to North American economic integration may be considerable. The United States and Canada do, however, maintain the world's largest bilateral trade relationship, with U.S.-Japan trade in second place, and U.S. trade shares with respect to its nonhem neighbor are significant in many sectors. About two-thirds (64 percent) of U.S. paper imports and 39 percent of transpon equipment imports come from Canada. Canada in turn buys two-thirds of U.S. nonferrous metal product exports, over half (51 percent) of its mining exports, and over one-third of its exports of leather (47 percent), nonelectric machinery (41 percent), transpon equipment (38 percent), nonmetal mineral products (37 percent), and textiles (34 percent). Generally speaking, the United States had significantly higher export dependence on Canada than import dependence under 1988 protection patterns.
United States' trade dependence on Mexico is generally lower than its dependence on Canada, as would be expected given the relative sizes of the three economies. Import dependence averages only 10 percent in primary sectors
and 5 percent in manufacturing (column 12) but is as high as 15 percent in agriculture and 8 percent in beverages.
As an export market, Mexico is more attractive to some U.S. sectors (column 16), although the averages for primary
and manufacturing are only 6 and 7 percent, respectively. U.S. leather producers direct 37 percent of their exports to Mexico, and 28 percent of U.S. apparel exports were destined there in 1988. The lower economywide averages
for U.S.-Mexico trade shares indicate that considerable scope may exist for trade creation within, and diversion to, a Nonh American customs union.