Canada-United States interregional trade: quasi-points and spatial change

Interregional trade between Canada and the United States has undergone significant change since the inception of free trade. However, the magnitude of that change for the different regions in Canada and the United States has not been properly identified because of a lack of an appropriate measure. This paper introduces the concept of a quasi-point and employs a spatial point pattern test to measure the degree of change in the interregional trade of Canadian provinces and US states, with an emphasis of that change on Ontario. It is found that the degree of change in the interregional trade flows is related to the degree of change in the provincial tariff rates.