Extending McCallum's (1995) result, based on a gravity model of 1988 trade flows, that a typical Canadian province trades 22 times more with other provinces than with U.S. states of similar size and distance, this paper asks how Quebec trade patterns compare with those of other provinces. The results, based on revised data for 1988, 1989 and 1990, show that while the typical province trades more than 20 times as much with other provinces as with comparable U.S. states, for Quebec the multiple is even greater. Thus trade between Quebec and the United States appears to be an even less viable alternative to interprovincial trade for Quebec than it is for the rest of Canada. The implications of these results for international economics are considerable, as they show that trade linkages within a national economy are far greater than previously imagined. If these results are confirmed, they imply that the fabric of national economies is far tighter than that of the global trading system, even for countries operating without substantial trade barriers.
