In this study the impact of transportation improvements on Brazilian interregional commodity flows are considered. The decreasing friction of distance is measured by two variants of the gravity model. First, distance coefficients are calculated for trade among all states in 1942 and 1962. Second, distance coefficients for each state's imports are calculated separately and then related to state per capita income, for the year, 1962. Both the time-series and cross-section results indicate a significant diminution in the friction of distance in the course of Brazilian development. The degree to which trade has integrated the national economy is assessed by the convergence of agricultural prices. Not only have interregional price differentials tended to diminish, but regional price structures are becoming more similar. The interrelation of these price structures provides a method of regionalizing the Brazilian space-economy.
The extent of the market in a nation depends not merely upon its population and per capita income, but also upon the ease with which commodities can move from one location to another. In the course of development, interregional transportation networks improve, accelerating the rate of commodity flows. Increases in interregional trade lead to changes in regional commodity prices, which in turn may translate into changes in relative levels of regional income. In this essay, some of these consequences of transportation improvements are traced in the Brazilian context. First, the magnitudes of these improvements are sketched. Second, recent trends in the * Most of the data for this study were collected during the author's tenure as Ford Foundation Visiting Professor at