deforestation (bSerr?o/b and Homma, 1993). High transportation costs between the Amazon and the rest of the country, which lead to high agricultural input costs and limit interregional trade, also affect deforestation. Pfaff (1997) b....../b Companhia bVale/b do Rio Doce, Brazil. Coy, M. (1992) Pioneer front and urban development: social and economic differentiation of pioneer towns in northern Mato Grosso (Brazil). Applied Geogra- phy and Development 39, 7?29. ...