Abstract:
The position taken in this study is that long run sustainability is a complex and context dependent concept, implying that the estimation of value depends on the issues at stake, the decision actors involved and the criteria being emphasised. Sustainability connects the economic process explicitly to the natural environment and the study elucidates how thermodynamics can supplement, although not substitute economic analyses. Both natural and social systems are multidimensional and changes are difficult to assess in a simple, one-dimensional way. The standard assumptions in many decision methods concerning rationality are thus hardly adequate.

The empirical focus is on agricultural production and wastewater handling and in four papers decision supporting tools presuming different types of criteria, scales and degrees of commensurability are analysed. In paper 1, energy utilisation in crop and dairy production systems is analysed through systems modelling showing that variation across different production intensities, thus giving valuable information for the evaluation of the sustainability of various systems. In paper 2, an LP-model is used to find cost-efficient combinations of wastewater systems given a restriction on total pollutant load to a recipient. In paper 3 it is observed that a shift from a household strategy to a recipient strategy is allocatively cost-efficient and increases flexibility. Still the household strategy dominates in praxis. The paper discusses reasons for this i.e., transaction costs, implicit rights modifications and loss aversion. In paper 4, a multicriteria planning model is used to handle value incommensurability when choosing between waste water systems. This is done through an explicit process where different decision actors articulate their preferences.

Key words: Not ready for WEB

The dissertation was handed to the committee for evaluation in June 2001, and successfully defended on October 12, 2001. Professor Arild Vatn was the advisor of this dissertation.

Karen Refsgaard was born in Otting in Denmark in 1962.. She currently works as a researcher in the Norwegian Agricultural Economics Research Institute in Oslo, Norway.