The paper discusses and redefines the traditional concept of externalities. Inspired by J.R. Commons' theory of institutional evolution we define externalities as policy relevant institutional interdependencies. Our concept of externalities is more general and reflects institutional failure...

The paper analyzes the conflict between illegal and legal exploitation of wildlife species in an East African context. In the model there are two agents, an agency managing a national park of fixed area and a group of local people living in the vicinity of the park. The park agency has the legal...

In this paper we analyze the exploitation of wildlife in a Third World context. In the model there are two agents: an agency managing a habitat area of fixed size and a group of peasants. The agency managing the habitat area has the legal right to exploit the wildlife, while the local people...

The paper analyses economic and ecological mechanisms determining wildlife investments in the context of pastoral exploitation of the semi-arid African rangeland. We consider a group of pastoralists practising two production activities, cattle herding and wildlife harvesting. Livestock and...

We study the economy and ecology of sheep farming under future climate change scenarios. The analysis is at the farm level and includes two different categories of the animals, ewes (adult females) and lambs with a crucial distinction between the outdoors grazing season and the winter indoors...

This chapter develops a sustainable economic yield harvesting model for the wild Atlantic salmon (Salmo salar) where the population comprises different age classes. It is shown that the weight–fecundity relationship of the spawning population, comprising two age classes, is crucial for the...

This paper explores the ecological and economic impacts of interactions between escaped farmed and wild Atlantic salmon (Salmo salar, Salmonidae) over generations. An age- and stage-structured bioeconomic model is developed. The biological part of the model includes age-specific life history...

The escape of cultured fish from a marine aquaculture facility is a type of biological invasion that may lead to a variety of potential ecological and economic effects on native fish. This paper develops a general invasive species impact model to capture explicitly both the ecological and...

Economic interdependency of wildlife or fish stocks is usually attributed to ecological interdependency, such as predator - prey and competitive relationships, or to density dependent migration of species between different areas. This paper provides another channel for economic interdependency...

This paper presents a bioeconomic analysis of a red deer population within a Norwegian institutional context. This population is managed by a well-defined manager, typically consisting of many landowners operating in a cooperative manner, with the goal of maximizing the present-value hunting...