This paper examines changes in net value added generated through Canadian and U.S. farm production, 1970-2000. We consider how the structural changes in Canadian and U.S. agriculture have affected the size and distribution of net value added and its components: rent, capital, labor, and to net farm income. We use the Theil Measure of Inequality (TMI) to compare and explain changes in 1) the between and within-region distribution of net value added, and 2) changes in the distribution of factor shares of net value added in Canada and in the U.S. Results show that in Canada (1960-2000), net value added has become somewhat more equally distributed relative to the number of farms per province, but has varied widely from 1972-1988. Between-region inequality in net value added accounted for from 0.5 to 85.5 percent of this inequality from 1960-2000. In the U.S. (1949-2000), net value added has become more unequally distributed. About half of the variation in net value added in the U.S. is due to between-region variation and about half to within-region variation in net value added. We find that most of the variation in the components of net value added (returns to capital, labor, nonoperator landlords, and to farm operators) in Canada and the United States is due to variations across regions, rather than to variations in the components of net value added themselves. These variations have generally been due to macroeconomic differences in regions, such as shifts in enterprise specialization, urbanization, changes in government programs, and to other structural changes in agriculture.