Publications > Cahiers (English)> N° 4, april 1987

Environnement et ressources naturelles
[Environment and Natural Resources]

• [The impact of agricultural practices and policies on the environment], L.-P. Mahé,
  P. Rainelli
• [Rent and profit in matter of halieutic resources management], J.-P. Boude, M. Morisset, J.-P. Revéret
• [Use of public coastal areas for oyster culture and tarification topics], P. Dumont
• [A model or regional by-products supply], V. Réquillart
• [Is quarries restoration profitable or not ?], F. Bonnieux, P. Rainelli
• [The irreversibility effect in environment economy], J.-P. Amigues

L'impact des pratiques agricoles sur l'environnement
[The impact of agricultural practices and policies on the environment]

L.-P. Mahé, P. Rainelli

In : Cahiers d'Economie et Sociologie Rurales, n° 4, april 1987, pp 9-31

Abstract : Agricultural practices have now become harmful to the environment to a signifiant extent. Not only long run productive pretentials are endangered but serious risks on human health are also generated by agricultural inputs pollution like nitrates. But there are also less reversible or even completely irreversible implications of the way agriculture has developped over these last decades. Adapting the countryside to modern technology also means standardization of landscape, loss of wild life diversity and in several instances species extinction. An analytical framework is used to highlight the economics of agricultural pollution due to intensive farming. Economic growth has contributed to enlarge the gap between intensive practices and social optimum. The problem is set in perspective of price support policies which have exacerbated the incentives to increase the purchased inputs-to-land ratio. The price of land is working as a lever in that process. It is suggested that neither price support cut, nor input taxes alone are likely to be sufficient tools to solve the agricultural pollution problem. They may help alleviate the situation, however.

Key-words : environment, agricultural practice, agricultural policy, agricultural pollution, agricultural development.

Rente et profit en matière d'exploitation des ressources halieutiques
[Rent and profit in matter of halieutic resources management]

J.-P. Boude, M. Morisset, J.-P. Revéret

In : Cahiers d'Economie et Sociologie Rurales, n° 4, april 1987, pp 33-44

Abstract : In regard to matter of management of living resources most theoretical writings relating to fishing economics refer to the notion of rent for calling monetary surplus brought out by the production activities. This paper attends to define the notion of rent and of profit in matter of halieutic resources management by the light of attainments of the different schools of thaught. This allows to give a better answer to the questions asked from the economists in matter of management or renewable resources.

Key-words : halieutic resources, rent, profit, fishing economics.

Utilisation du domaine public maritime par l'ostréiculture et problèmes de tarification
[Use of public coastal areas for oyster culture and tarification topics]

P. Dumont

In : Cahiers d'Economie et Sociologie Rurales, n° 4, april 1987, pp 45-66

Abstract : This article is an attempt to assess the profitability of public coastal areas for oyster producers by means of linear programming models. The shadow price is higher than the fees which are due to the state. This explains why some sales of public grounds take place among oyster growers. It also contributes to the underexploitation of the regions along the coast available for oyster culture. The competition between oyster producers and between the oyster culturing industry and other activities involve external effects. They require that a distinction be made between social and private profitability. The allocation of coastal areas implies social transfers between various economic agents : oyster producers, the State, consumers, and other users of coastal domain.

Key-words : coastal area, oyster culture, public ground.

Un modèle d'offre régionale de sous-produits agricoles
[A model or regional by-products supply]

V. Réquillart

In : Cahiers d'Economie et Sociologie Rurales, n° 4, april 1987, pp 67-86

Abstract : From a technological point of view, prospects of industrial valorisations of ligno-cellulosic products are important. In this paper we first present specificities of supply of by-products. The market appears to be an oligopoly which implies a price higher than the marginal cost. We also show the dilemma farmers are facing, namely : to sell by-products in order to increase the income in a short term with the risk of a decline of future incomes, due to a loss of fertility, or to incorporate by-products. A simple theoretical model presents this dilemma. The application of this model is difficult because of a lack of data. In a second part, we present a model of regional supply of by-products, allowing an analysis supply of industrial plants. The model allows to take into account some keys factors, namely supply characteristic including risk, constraints of soil fertility maintenance, problems of harvesting transportation and storage of products. An example of utilisation of this model is presented.

Key-words : valorisation of agricultural by-products, model, regional supply of by-products.

Le remblaiement des carrières peut-il être intéressant ?
[Is quarries restoration profitable or not ?]

F. Bonnieux, P. Rainelli

In : Cahiers d'Economie et Sociologie Rurales, n° 4, april 1987, pp 87-96

Abstract : Since 1971, law has prescribed the reclamation of quarries after exploitation. Restoration is not compulsory for quarries exploited previously. This study reports an attempt to assess the economic advantage of such restoration. It considers different types of restoration involving various costs and levels of profitability. The profitability for agricultural purposes, especially in the case of dairy farms, is very low. Soil restoration can be economically justified only if there is an opportunity of housing development. On the other hand, reclamation is valuable for recreational fishing. From the point of view of public economy, soil restoration appears to be gainful if associated externalities are taken into account.

Key-words : soil restoration, reclamation of quarries, profitability, public economy.

L'effet d'irréversibilité en économie de l'environnement
[The irreversibility effect in environment economy]

J.-P. Amigues

In : Cahiers d'Economie et Sociologie Rurales, n° 4, april 1987, pp 97-112

Abstract : Decisions of developing natural zones often involve dramatic alterations of the environment. When the development is irreversible and its expected benefits uncertain, it may be profitable to postpone the decision in order to make use of further information opportunities. In this case, conservation of the environment exhibits a specific positive value, the so-called "quasi option value" even if risk neutrality of the decision maker is assumed.

Key-words : environment economy, decision of development, irreversibility, quasi option value.