The paper analyses the relation between demographic transformation, agricultural transformation and land-use pressure within a simple agrarian economy where population is treated both as a cause and consequence of economic changes. In this Malthusian-type of economy, population growth and food...

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...

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 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...

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...

Without resorting to the folk theorem or to altruistic preferences, we demonstrate that the problem of overharvesting among individually rational harvesters in a local commons vanishes if the harvesters share, and voluntarily contribute to, some public good. Formulating the model as a two-stage...

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...