Soil erosion and soil mining are important environmental problems in many developing countries and may represent a considerable drag on economic development. The cost of soil degradation depends, however, not only on the productivity effects it has on agricultural growth, but also on how the agricultural sectors are linked to the rest of the economy. This article describes an integrated economy–soil-productivity model for Ghana, and through several simulated scenarios we calculate the drag on the Ghanaian economy of soil mining and erosion, and illustrate the effects of different policies aiming at a reduction in these environmental problems.

This article develops a model of wild-resource exploitation that includes both the standard bioeconomic properties of growth and harvesting and a species-area relationship linked to habitat conversion. The model is developed for both a closed and an open economy. In the closed-economy model the characteristics of the long-run equilibrium are analysed in three versions of the model: the basic bioeconomic model, the inclusion of habitat conversion and the addition of biodiversity value. In the case of the open-economy model, we also examine the potential effects of trade interventions on the optimal exploitation of species and habitat conversion in the long run. The results confirm that the inclusion of habitat conversion as well as biodiversity value in a model of wild-resource exploitation yields significantly different outcomes than a basic bioeconomic model.

This article investigates the linkages between economic growth, energy consumption and carbon dioxide (CO2) emissions in India by analysing the structure of production and consumption in the Indian economy. We begin with an examination of the consumption pattern of six different income classes, three each in urban and rural India, and then estimate the direct and indirect energy and CO2 emission coefficients for supporting production in various sectors. This provides us with a basis for estimating the energy and emission content of the consumption baskets of the different income classes in India. CO2 emissions are projected to increase from 0.18 tonnes of carbon (tC) per capita in 1990 to about 0.62 tC per capita in 2020 under the reference scenario which corresponds to a GDP growth rate of 5.5% per annum. We then analyse scenarios of technology improvement in which emissions are reduced to 0.47 tC per capita in 2020. Our projection methodology takes into account the changes in aggregate consumpti on pattern due to mobility of the population across the income classes and from rural to urban areas, besides the increase in per capita consumption of all classes.

In one sense, everyone making a decision of any consequence uses something very like benefit-cost analysis. That is, they weigh up the pros and cons of the options confronting them and decide between them accordingly. Benefit-cost analysis is merely one systematic way of evaluating the economically relevant pros and cons of various options. The authors of the project appraisal manuals of the early 1970s (Mishan, 1971; Dasgupta et al., 1972; Pearce, 1972; Little and Mirrlees, 1974) were interested in establishing a set of rules that might ensure that the results of distinct social investment decisions would be efficient (or at least consistent). On the surface, the paper by Arrow et al. (1996) that is the focus of this forum merely argues for an extension of benefit-cost rules to an area where, as David Pearce points out in his commentary, policy-making tends to be dominated by hasty, ill-conceived, ad hoc responses to the pressures of the moment. The paper argues that environmental, health and safety regulations in the US could and should be informed by an analysis of their economically relevant costs and benefits.

The general argument presented by Arrow et al. runs as follows: government regulation might improve on free market outcomes, since markets sometimes misallocate resources. However, the costs of regulations need to be assessed against their presumed benefits. Benefit-cost analysis is a valuable technique for making such an assessment, even though it was developed for the appraisal of physical investment projects. However, since the technique is not perfect, it should not provide the only input into the process, but rather be part of an array of evidence.

The growing impact of regulations on the economy has led both Congress and the Administration to search for new ways of reforming the regulatory process. Many of these initiatives call for greater reliance on the use of economic analysis in the development and evaluation of regulations. One specific approach being advocated is benefit-cost analysis, an economic tool for comparing the desirable and undesirable impacts of proposed policies.

The thrust of the principles enunciated in Arrow et al. is that economic benefits and costs can be a great help in organizing disparate concerns, in identifying issues, and in designing regulatory policies and individual projects with environmental impact. While this true, I must disagree with the authors that 'formal benefit-cost analysis should not be viewed as either necessary or sufficient for designing sensible public policy' (p. 201). At least there can be little doubt that cost-benefit analysis is necessary for sensible policy. I comment below from the perspective of devloping countries.

Arrow et al. revisit the case for using benefit-cost analysis in a developed country, the USA, where markets work reasonably efficiently and where the capacity to implement such studies is undoubted. Their recommendations deserve wholehearted support in that context, particularly their recommendation 1 calling for a comparison of gains and losses from regulatory actions. Those who have not worked in government will recognise that most decisions are not in fact made with any form of calculus that we might describe as 'cost benefit thinking'. Indeed, the whole process of policy priority setting is all too often ad hoc, reactive, crisis-based and over-responsive to often ill-informed pressure groups (of all kinds).

Can benefit-cost analysis (BCA) be used in the developing world in the same way in which it is used in developed market economies? The paper by Arrow et al. makes a good case for employing BCA to evaluate environmental, health, and safety regulations in the United States. It offers a number of principles to guide the use of benefit-cost analyses, some of which can be applied to developing countries. Conservation policies in the tropics can help illustrate the relevance of BCA for evaluating regulations in less industrialized countries. I use a set of studies on the Mantadia National Park to show in practical terms how and when BCA can serve as an effective evaluative tool.

Among the tools of the economic trade, cost-benefit analysis is the most widely used in policy circles. Asking whether there is a role for cost-benefit analysis is like asking whether there is a role for the weatherman. Of course there is.