[1] Univ Puerto Rico, Dept Agr Econ & Rural Sociol, Mayaguez 259 Blvd Alfonso Valdes Cobian, Edificio, Mayaguez, PR 00681 USA
[2] ISDC Int Secur & Dev Ctr, Auguststr 89, D-10117 Berlin, DE, Germany
[3] Univ Connecticut, Dept Agr & Resource Econ, 1376 Storrs Rd, Storrs, CT 06269 USA
[4] Pforzheim Univ, Tiefenbronner Str 65, D-75175 Pforzheim, DE, Germany
[5] Ecuadorian Secretariat Higher Educ Sci Technol & I, Quito, Ecuador