Systematic trends in the general price level of goods and services are the subject of extensive measurement and significant interest among researchers, policy makers and the general public. Dynamic price measurement is also important in environmental accounting in that real measures of augmented output are required to draw inferences on sustainability. This paper computes price indices for emissions of five air pollutants in the United States. Using marginal damages, the paper computes Paasche, Laspeyres, Fisher and Tornquist index numbers for five air pollutants spanning the period 1999–2008 for use in computing real environmental accounts. Evidence of time series heterogeneity in the marginal damages is detected: marginal damages for nitrogen oxides increase by a factor of two and marginal damages for NH3 decrease by one-half. The analysis finds that nominal gross damages from air pollution in the United States decrease by 40 per cent between 1999 and 2008.

This paper contains a critical assessment of the claim that NNP can be used for welfare comparisons. The analysis assumes that national accounts are comprehensive (in particular ‘greened’ by taking into account environmental amenities and natural resource depletion), but does not assume optimal resource allocation. The general conclusion is that greater NNP corresponds to welfare enhancement only if net investment flows are revalued. Real utility-NNP and real measurable NNP made comparable across time by means of a consumer price index allow for such revaluation, and thus indicate welfare improvement.

This study predicts the impact of climate change on African agriculture. We use a generalized linear model (GLM) framework to estimate the relationship between the proportion of various Agro-Ecological Zones (AEZs) in a district and climate. Using three climate scenarios, we project how climate change will cause AEZs to shift, causing changes in acreage and net revenue per hectare of cropland. Our results predict that Africa will suffer heavy annual welfare losses by 2070–2100, ranging between US$14 billion and US$70 billion, depending on the climate scenario and cropland measure considered.

Using stream water polluted with untreated wastewater in agriculture is controversial due to its combination of benefits and negative health impacts. Using data from a household survey, ‘wastewater’ and ‘freshwater’ farmers were analysed comparatively to examine the perceived impacts of irrigation water quality on farmers' health and to evaluate the extent of health damage. Probability of illness was estimated using the theory of utility-maximising behaviour of households subject to the conventional farm household production model, augmented by adding a health production function. Reduced model and instrumental variable probit specifications both show that perceived illness prevalence is significantly higher for household members working on wastewater irrigation farms than for those working with freshwater. Our data entails econometric complications (e.g., endogeneity of farmers' behaviour, unobserved location-specific characteristics). Ignoring these will result in underestimation of the value of policy interventions designed to reduce potential health damage of wastewater use in irrigation.

Research on PES programs in agro-ecosystems is recent and limited in developing countries. The authors use a multi-method, quasi-experimental impact evaluation approach to examine direct and indirect livelihood impacts of the Equitable Payments for Watershed Services (EPWS) program piloted in the Morogoro region in Tanzania. The evaluation is based on a survey of 116 program participants and 117 non-participants, 32 semi-structured interviews and 16 focus group discussions to complement the survey data. They find that, while the EPWS program incentives resulted in direct benefits, indirect benefits such as increased crop yields, higher land values, new employment opportunities, more knowledgeable farmers, improved leadership skills as well as increased trust, expanded internal and external networks and strengthened institutions were more important. The results clearly indicate the potential of PES schemes to generate win-win outcomes in agro-ecosystems, but they also call for attention to equity in the design of PES programs implemented on agro-ecosystems.

Global forests could play an important role in mitigating climate change. However, there are significant implementation obstacles to accessing the world's forest carbon sequestration potential. The timing of regional participation and eligibility of sequestration activities are issues. The existing forest carbon supply estimates have made optimistic assumptions about immediate, comprehensive, and global access. They have also assumed no interactions between activities and regions, and over time. We use a global forest and land use model to evaluate these assumptions with more realistic forest carbon policy pathways. We find that an afforestation only policy is fundamentally flawed, accelerated deforestation may be unavoidable, and a delayed comprehensive program could reduce, but not eliminate, near-term accelerated deforestation and eventually produce sequestration equivalent to idealized policies – but with a different sequestration mix than previously estimated by others and thereby different forests. We also find that afforestation and avoided deforestation increase the cost of one another.

We study the welfare and energy poverty implications of energy price change scenarios in Indonesia. Our analysis extends previous analyses of energy price impacts at the household level in three ways. First, by employing a household energy demand system (QUAIDS), we are able to distinguish between first- and second-order welfare effects over the income distribution. Second, our results point to the ownership of energy-processing durables as another source of impact heterogeneity. Third, we extend the welfare analysis beyond the money-metric utility effects and look at energy poverty, which is understood as the absence of or imperfect access to reliable and clean modern energy services. The analysis indicates that energy prices may serve as an effective instrument to reduce energy use but also have important adverse welfare effects. The latter can, however, be mitigated by appropriate compensation policies.

Gasoline and diesel fuel are heavily taxed in many developed and some emerging and developing countries. Outside the United States and Europe, however, there has been little attempt to quantify the external costs of vehicle use, so policy makers lack guidance on whether prevailing tax rates are economically efficient. This paper develops a general approach for estimating motor vehicle externalities, and hence corrective taxes on gasoline and diesel, based on pooling local data with extrapolations from US evidence. The analysis is illustrated for the case of Chile, although it could be applied to other countries.

We explore poor farmers' incentives to adopt production systems that increase soil carbon sequestration, focusing on the impact of risk. A dynamic optimization model of conservation agriculture adoption is presented, where farmers optimize over expected utility of profits from agriculture and carbon sequestration. Adoption impacts on agricultural productivity are modeled as a combination of the technological effects of the new system, and productivity effects of changes in soil carbon on agricultural output. Comparative static results indicate increases in soil carbon sequestration price and the discount rate have unambiguous impacts on equilibrium soil carbon levels; the former leading to higher, and the latter to lower, carbon levels. Increases in the price of agricultural output and risk aversion have ambiguous impacts, depending on the relative strength of the productivity and technology effects. The paper concludes with a discussion of designing soil carbon payment mechanisms to benefit low income farmers.

Many opportunities exist to take advantage of integrated surface water–groundwater management with consequent resource and investment savings. In inappropriate legal and administrative settings, groundwater becomes an open-access resource leading to excessive contemporary and inter-temporal externalities. Several policy instruments have been used to correct these externalities: limits in well spacing and capacities, pumping taxes and tradable pumping permits. Urban–agricultural competition for limited groundwater need not result in crises for either sector if these instruments are used to mediate the competition. In the case of non-renewable stocks of groundwater, rates of economic and demographic development should be planned in keeping with long-term criteria to avoid overly rapid exploitation of the resource, non-sustainable population levels and inappropriate investment in infrastructure. Island states and coastal areas have special problems related to saltwater intrusion and coastal subsidence that can be mitigated if not eliminated through the use of economic and physical measures. Five brief case studies illustrate these points.

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.

The authors develop a theoretical model that elucidates the relationship between the quality of governance, the composition of government spending and pollution as a by-product of the consumption process. In particular, they determine the impact of government spending that alleviates market failure such as subsidies to the poor which reduce credit market failure and environmental regulations to correct for pollution externality. It is found that a shift in government spending towards goods that alleviate market failure has countervailing effects – consumption pollution rises due to increases in income, but consumption pollution also falls due to increasing environmental regulations. Conditional on the government adopting a democratic regime, the effect through environmental regulations outweighs the effect through income leading to lower consumption pollution. The authors estimate an empirical model and find that the results support their theoretical predictions.

Continental-scale economic analysis suggests that changes in climate conditions are associated with lower agricultural net revenue in sub-Saharan Africa. Specific locations, however, may not reflect this overall trend due to variation in baseline climate, soils, and socioeconomic factors that are difficult to model at large scales. The economic effect of changes in climate conditions on agricultural revenue in particular places in sub-Saharan Africa remains largely unknown. To test this effect, we study an area of West Africa with high climate variation over a small geographic area. We find that higher temperatures and precipitation lower agricultural revenues in the more important rainy season but increase revenues in the less important cool, dry season.

A national campaign of well testing through 2003 enabled households in rural Bangladesh to switch, at least for drinking water, from high-arsenic wells to neighboring lower arsenic wells. We study the well-switching dynamics over time by re-interviewing, in 2008, a randomly selected subset of households in the Araihazar region who had been interviewed in 2005. Contrary to concerns that the impact of arsenic information on switching behavior would erode over time, we find that not only was 2003–2005 switching highly persistent but also new switching by 2008 doubled the share of households at unsafe wells who had switched. The passage of time also had a cost: 22 per cent of households did not recall test results by 2008. The loss of arsenic knowledge led to staying at unsafe wells and switching from safe wells. Our results support ongoing well testing for arsenic to reinforce this beneficial information.

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 incorporates both density-dependent and density-independent (stochastic) factors. Rodents are controlled by applying poison, and the costs are made up of the cost of poison plus the damage to maize production. We analyse how the present-value costs of maize production are affected by various rodent control strategies, by varying the duration and timing of rodenticide application. Our numerical results suggest that it is economically beneficial to control the rodent population. In general, the most cost-effective duration of controlling the rodent population is 3–4 months every year, and especially at the end of the dry season/beginning of rainy season. The paper demonstrates that changing from today's practice of symptomatic treatment when heavy rodent damage is noticed to a practice where the calendar is emphasized, may substantially improve the economic conditions for the maize producing farmers. This main conclusion is highly robust and not much affected by changing prices of maize production.

Environmental economics models are often too complex to be communicated in an illustrative manner. For this reason, this paper develops the Basic Climate Economic (BCE) model that features core elements of macroeconomic and climate economic modelling, while allowing for an illustrative examination of the development path. The BCE model incorporates fossil stock depletion, pollution stock accumulation, endogenous growth, and climate-induced capital depreciation. We first use graphical analysis to show the effects of climate change and climate policy on economic development. Intuition for the different model mechanisms, the functional forms, and the effects of different climate policies is provided. We then show the model equations in mathematical terms to derive closed-form solutions and to run model simulations relating to the graphical part. Finally, we compare our setup to other models of climate economics.

The effects of deforestation in Cameroon such as the erosion of agricultural lands, drying up water bodies during dry seasons, desertification, disappearance of plant and animal species, modifications of both local and regional climatic conditions and global warming through its effect on the global carbon cycle are likely to affect agricultural activities and economic growth. This paper investigates the immediate causes and consequences of deforestation in Cameroon between 1970 and 2000. Quantitative estimates show that coffee, and cocoa producer prices, food crop prices, and the timber export price index, on the one hand, and the oil boom, the structural adjustment policies, and the devaluation of the CFA franc, on the other hand, are quite important in stimulating the clearing of forests. Equally, the agricultural value added per hectare increases the profitability of maintaining forests. The implication of these results is that the importance of non-forest policies is underappreciated in Cameroon.

In this paper we assess the potential economic effects of climate change on Brazilian agriculture scenarios in different regions in a general equilibrium framework, using a detailed regional economic database for the year 2005. Two different climate change impact scenarios are simulated. This paper extends the Brazilian literature in three different ways: by considering detailed shocks by product and region; by highlighting the connections between the potential impacts of climate change on agriculture and the labor market, with an inter-regional focus; and by specifying the links between climate change forecasts for agriculture and household expenditures. Results show that climate change impacts on Brazilian agriculture would have a relatively small economic effect on the Brazilian economy in aggregate terms, but with severe consequences at the regional level, making a strong case for losses that would be concentrated in the poorest regions and for the poorest workers and households in those regions.

This study compares the management performance of timber production among three management systems in Nepal: private forestry, community forestry with collective management, and community forestry with centralized management. While collective management relies entirely on community labor for the whole management, centralized management uses community labor for the protection of forests and hired labor for silvicultural operations, for example weeding, pruning, and thinning. We found that collective community management is less costly for the protection of planted trees but allocates less labor for the management of trees than private management. We also found that centralized management of natural forests leads to higher revenue and profit than collective management. These findings support the hypothesis that, while collective management is more efficient than private management for the protection of trees due to effective mutual supervision, profit-seeking private management or centralized management is more efficient than collective management for silvicultural operations due to superior work incentives. This study, however, failed to compare efficiency of private and centralized management.

The Mekong River Basin (MRB) is a trans-boundary river shared by six countries. The governance by the Mekong River Commission (MRC) of the Lower Mekong Basin (LMB) is weak. This study investigates the welfare effects in the year 2030 arising from strengthening the MRC's governance versus joint management of the entire MRB. Without joint management, strengthening the MRC's governance has a huge potential to achieve welfare gains and it requires that the interests of all stakeholders be equally balanced. A bargaining approach shows that the LMB has no incentive to negotiate with China and is better off strengthening the MRC's governance instead. If such strengthening could be realized, further welfare gains of joint management by a wider and stronger MRC, including China, would be very small.