LAUSR

Low agricultural productivity remains the primary source of poverty in the developing regions and yet little is known about the influence on agricultural productivity of domestic and international accumulated R&D knowledge and the channels through which this knowledge is transmitted internationally. Following a large scientific literature, this article argues that R&D and R&D knowledge spillover are ecozone†specific and, therefore, are transmitted internationally through ecozones, where ecozones are the broadest biogeographic division of the earth's land surface. Using data for a panel of 88 countries, it is shown that international knowledge spillovers are ecozone†specific and have been an important contributing factor behind the marked widening of the income gap between developed and developing countries since 1983.