The Economics of Biodiversity Loss and Agricultural Development in Low Income Countries

Introduction Biodiversity conservation has traditionally been seen as problem of protecting genetic diversity. It has had two dimensions: ex situ germ plasm preservation in zoos, aquaria and arboreta (and by extension, seed banks, tissue cultures and genomic libraries), and in situ species preservation in refugia, especially in megadiversity areas involving high levels of endemism. Increasingly, however, biodiversity conservation is being taken out of zoos and protected areas. It is recognised that biodiversity is important for the functioning of all ecosystems, and that excessive loss of biodiversity imposes real costs on resource users (Heywood, 1995). It is therefore interesting to consider the problem of biodiversity loss not just in refugia, but in managed ecosystems. These are ecosystems from which some species have been deleted in order to enhance the productivity of others. The problem of biodiversity conservation in such cases does not therefore involve preservation of all existing species. It involves maintenance of sufficient interspecific and intraspecific diversity to protect the productivity of the system. Put another way, the problem of biodiversity conservation in managed systems requires us to think about the optimal or efficient level of species deletion. The main question I want to pose in this paper is whether current rates of biodiversity loss are efficient. This is not an uncontroversial way to look at the problem. It implies that it is reasonable to apply conventional economic tests to biodiversity loss, and many regard such an approach with repugnance. Wilson (1984, 1993), for example, argues that humans have an inherent inclination to affiliate with life and lifelike processes and these innate tendencies form a basis for an ethic of care and conservation of the diversity of life. But to say that there may be an efficient level of biodiversity implies that it may be optimal to drive some species to extinction (if only locally). While most people have little difficulty with this suggestion when the species at issue are, say, the AIDS or smallpox viruses, there is less consensus about endemic agricultural pests or competitors. Nevertheless, this is the approach I want to take: to consider whether current rates of biodiversity loss in agroecosystems are efficient. The paper does not report original research results, but uses existing literatures in ecology and economics to consider three aspects of the problem. The first, addressed in section 2, is to identify the external costs of biodiversity loss in agroecosystems in developing countries. …