Much of the contemporary concern for ’“structural change” in advanced economies has its origins in the significant changes in patterns of international trade which have occurred over the last two decades. While these changes in trade patterns are the joint consequences of developments in a number of interrelated dimensions (e.g., differentials in rates of technological innovation and diffusion and differential changes in relative factor prices, in rates of savings and capital formation, in the vintage of the capital stock and in primary materials and energy prices and availabilities), a growing emphasis in a number of countries on the environmental consequences of productive activities has constituted an important contributing factor, serving to discourage apparently “environmentally-adverse” (“ pollutionintensive”) production in some countries and to encourage the transfer of that production to countries in which environmental concerns are less intense (or impinge less severely on productive activity).