The Salmon industry in Norway includes three sectors, namely sea and river fishing for wild salmon, and salmon farming, or aquaculture. The three sectors provide different social, economic and cultural benefits to society, but also face many problems and challenges. They have different...

This paper develops an optimal harvesting model for the wild Atlantic salmon (Salmo salar), where various age classes of the population is included. It is shown that the marginal value-fecundity relationship of the spawning population, comprising young and old fish, is crucial for the optimal...

The literature on catching up suggests that due to diffusion and imitation relatively backward countries should grow at a faster rate. A model along lines suggested by Abramovitz is constructed to examine this. A country's change in productivity (technological gap) is supposed to depend on the...

The paper treats the economy of controlling an African pest rodent, the multimammate rat, causing major damage in maize production. An ecological population model is presented and used as a basis for the economic analyses carried out at the village level using data from Tanzania. This model...

The paper analyses the social optimal management of terrestrial animal species where land-use costs, non-consumptive benefits of the wild species and nuisance costs, in addition to harvesting profit, are taken into account. When there is harvesting, it is demonstrated that increased...

After coming close to extinction, the grey wolf (Canis lupus) has re-colonized Scandinavia during the last two decades. The current population numbers some 100–120 individuals, and is distributed in small packs along the Swedish–Norwegian border. However, with wolf re-colonization, several...

A model analyzing the economics of sheep farming is formulated. The basic idea is simple. Sheep are capital and they are held by farmers as long as their capital value exceeds their slaughter, or meat, value. The farmers are therefore portfolio managers aiming to find the optimal combination of...

This paper formulates a simple biomass growth model of a fishery. In this model, fish are exploited in a restricted open-access regime where a fixed number of harvesters exploit the fish stock in a myopic profit-maximizing manner. It is demonstrated that more modern fishing technology has a...

Biodiversity is today threatened by many factors of which destruction and reduction of habitats are considered most important for terrestrial species. One way to counteract these threats is to establish reserves with restrictions on land-use and exploitation. However, very few reserves can be...