Joao plinio Juchem neto Universidade Federal do Pampa, Campus Alegrete   Av. Tiaraju, 810 Bairro: Ibirapuita Alegrete, RS 97546-550 Brazil   plinio@unipampa.edu.br   www.unipampa.edu.br           JEL Areas: R0 : Urban, Rural, and Regional Economics: General O4 : Economic Growth and Aggregate Productivity: General