Aquaculture experienced a significant global expansion at the end of the 20th century, becoming one of the fastest growing sectors of animal husbandry and production during that period. Chile's contribution to world expansion of salmon and trout production was notorious, given that in a short twenty five-year period it became one of the leading world producers. One prominent feature of salmon production in Chile is that the industry concentrated geographically in a limited area around Puerto Montt, in Region 10 of the country. Industry concentration cannot be exclusively explained in terms of natural advantages, and evidence is presented in favour of Venables's model (1996). A qualitative analysis of the evolution of the industry is presented to provide evidence of input-output linkages, economies of scale, competition and the progressive multiplication of inputs, applying two types of data sources: a review of the existing technical literature on the subject and in-depth interviews with 20 industry experts.

The aim of this research is to investigate the coherence and reliability of subjective crop yield probability density functions (PDF) elicited from a series of interviews carried out on a wide group of farmers. Three different elicitation techniques were used: the Two-Step PDF estimation method, the Triangular distribution and the Beta distribution. Subjects who were interviewed gave both estimates for point crop yield (mean, highest possible, most frequent and lowest possible) and for the PDF based on interval estimates. To evaluate persistence, two concepts were used: time persistence and methodological persistence. The results are deemed valuable in order to determine the level of trust in the techniques applied in obtaining data, and in their effectiveness in designing a farm decision support system (DSS).

The aim of this research was to investigate the persistence of annual crop yield point value subjective estimates, elicited from a series of interviews carried out on a wide group of farmers. Time persistence is a necessary condition of coherence and reliability in subjective crop yield probability estimation. The interviewed subjects gave estimates for point crop yield (mean, highest, most frequent and lowest possible). Limited relative differences for all variables were found, except for the lowest possible crop yield estimates, which had a broad dispersion. The results are deemed valuable in order to determine the level of trust in the techniques applied in obtaining data, and in their effectiveness in designing a farm decision support system (DSS) to enhance the outcome of farmers' decision making.

El artículo tiene como objetivo describir una metodología de selección de proveedores sostenibles basada en el proceso de análisis jerárquico y la técnica de preferencias ordenadas por similitud a una solución ideal para la minería del cobre. Con base en una revisión de la literatura, se desarrolla un modelo de selección de proveedores conformado por criterios de selección basados en las dimensiones de sostenibilidad, e incluye un modelo de ponderación de factores con base en comparaciones ordenadas. Esta metodología se valida en una compañía minera de cobre ubicada en la región de Antofagasta, Chile. Con los resultados se encuentra que la aplicación del proceso de análisis jerárquico y las técnicas de preferencia de ordenadas por similitud como una solución ideal que apoya el proceso de toma de decisiones y aumenta las capacidades para la selección de proveedores sostenibles al utilizar modelos cuantitativos y escalas de comparación de criterios que consideran la subjetividad en las decisiones. De esta manera, se contribuye al mejoramiento de empresas mineras, donde el proceso de compras y la gestión de proveedores son componentes críticos del sistema logístico minero.

No abstract