This thesis, consisting of six methodological and empirical articles, treats cases from the forest area, with a special focus on forest biodiversity. The basic approach is how maintenance of biodiversity from a forest can be compared, within economic analysis, to the provision of forest goods with market prices. Biodiversity will normally comprise non-market / public goods. The typical scenario is a presumed conflict between timber production and the preservation of specific forest habitats that harbour endangered plant and animal species. The method applied to economically valuing changes in forest biodiversity is contingent valuation (CV), a survey method that is described and discussed from various angels in the following articles.