The economics of climate change in agriculture

This paper presents a conceptual frameworkof the impact of climate change onagriculture. It assumes that climatechange will result in a fertilizationeffect and a shift of agro-ecologicalconditions away from the Equator towardsthe Poles. The agro-ecological shift islikely to reduce yield because of reducedacreage and the fertilization effect willincrease yield. The aggregate effectdepends on whichever of the two dominates. The overall effect of climate change may beless significant than its distributionaleffects and the results are consistentwith previous empirical studies. Theimpact of climate change depends on itspace. Faster changes in climate willresult in higher cost. The assessment ofthe cost has to consider that climatechange is a dynamic phenomenon that mayrequire continuous adjustment. Environmental regulation that emphasizesconservation may increase cost ofadjustment and environmental policiesshould emphasize adaptation andflexibility.     

Intrapericardial teratoma with hydrops leading to in utero demise

We report a case of intrapericardial teratoma following in utero demise at 29 weeks with nonimmune hydrops. The diagnosis was strongly suggested by ultrasound findings and confirmed by fetopathology. The mechanism whereby intrapericardial teratomas may lead to hydrops and death is massive pericardial effusion responsible for compressive tamponade. When prenatal diagnosis is performed before this stage, in utero interventions can obtain decompression, and the birth can be planned with rapid and appropriate management of the neonate. Copyright © 2007 John Wiley & Sons, Ltd.     

Optimal exploitation of energy resources: Solar power and electricity generation in below sea level basins

This paper analyzes the generation of hydroelectric power by the transfer of seawater to locations which are significantly below sea level (e.g., the Dead Sea in Israel and the Qatara depression in Egypt) combined with solar energy that via evaporation will perpetuate the hydroelectric power capacity. Two scenarios are depicted. The first focuses on optimal planning of the canal capacity and optimal use of its water to generate hydroelectric power while filling the basin to its steady-state level. The second includes the impact of solar pools as a new technology whose date of adoption is a random event. It is shown that the optimal flow of water through the canal depends on the relationship between optimal canal capacity and the rate of water evaporation in the basin. The optimal design of the canal can be considered a hybrid between depletion of a natural resouce (the height differences in filling up the basin) and use of a renewable resource (solar energy to evaporate the basin water). The optimal policy is shown to consist of sequential intervals, some of which may vanish under certain conditions: first, the operation of the canal at full capacity; then the gradual decrease of water flow at a rate equal to the elasticity of the marginal product of electricity generation times the sum of interest rate and the marginal evaporation rate; and, finally, the stabilization of the water flow at the rate of steady-state evaporation. The stochastic model with the introduction of solar pools technology treated as a random event is formulated as a two-stage maximization problem. It is shown that, in contrast to the scenario without solar pools, the canal may be operated underutilizing its capacity in the initial period. But even in this case, the quantity of water flowing through the canal is a nonincreasing monotonic function over time with a jump in the quantity of flow at the date the solar pools are introduced.     

Optimal Environmental Health Regulations with Heterogeneous Populations: Treatment versus “Tagging”

In this paper, we develop a model of population level environmental health risk with individuals that are heterogeneous in their susceptibility to environmental toxins. This framework allows us to determine when it is optimal to target vulnerable subgroups of the population with special exposure-reducing treatments. Our analytic results show that the potential economic gains from targeted policies will depend critically on the quality of existing capital, the degree of returns to scale in treatment technologies, and the size and sensitivity of the vulnerable population. An empirical application of the model is extended to the case of cryptosporidium in drinking water supplies.     

Two-goal regional environmental policy: The case of the Santa Ana river basin

In determining public policy measures, the value of information about the functional relationships between targets and instruments can hardly be understated. In the present paper these macrorelations are obtained for a competitive industry by way of aggregation over many individual firms following simple behavioristic patterns. With the exact knowledge of the macrorelations, obtaining the numerical values of the instruments becomes a simple mathematical programming problem. These principles are applied in examination of the water pollution problems generated by the dairy industry in the Santa Ana River Basin where local governments face the problem of controlling environmental quality with minimum opportunity costs in terms of output.     

Two-goal environmental policy: An integration of micro and micro ad hoc decision rules

A method of predicting and comparing the immediate impact of different environmental policies and of selecting the optimal policy is suggested in this paper. The degradation of water quality by a polluting industry is used to demonstrate this approach. Aggregation over this industry consists of firms with “putty clay” properties in production, and credit constraints in the capital market generate the macrorelations. The macrorelations which depend on the level of the policy variables are expressed in terms of probabilities and moments of the distribution of the microrelations and are used for different planning purposes.     

Environmental policy with collective waste disposal

Centralized collection and disposal is an integral component of waste management strategies for many solid and liquid wastes, and carbon capture and storage is currently being considered for gaseous waste. In this paper we show how collective waste disposal systems introduce essential changes in the design of optimal environmental policy. Absent collective disposal, an optimal environmental policy imposes relatively stringent regulations on polluters in regions where local environmental damage functions are “high”; however, under collective waste disposal, the optimal environmental policy level increases monotonically over distance from the disposal site, and this is true irrespective of the degree of spatial heterogeneity in local environmental damage functions. We characterize the optimal spatial pattern of environmental policy levels under collective waste disposal and identify optimal membership size for waste disposal networks comprised of homogeneous producers.     

Green markets, eco-certification, and equilibrium fraud

Consumers voluntarily pay significant price premiums to acquire unobservable environmental attributes in green markets. This paper considers the performance of eco-certification policy under circumstances where consumers cannot discern environmental attributes in goods, but are able to form rational expectations regarding the extent of illicit activities in the green market. The main results are: (i) fraud is less prevalent in green markets when entry barriers limit the number of firms; (ii) conventional environmental policies on polluting techniques increase the incidence of fraud, and can even preclude the use of non-polluting techniques which would otherwise emerge in green markets; (iii) voluntary eco-certification policies can decrease fraud, increase output, and raise profits per firm; and (iv) in cases where the socially optimal resource allocation can be supported, the optimal policy involves negative unit certification fees, positive fixed certification fees and is revenue-generating for the certifying agent.     

Environmental and Distributional Impacts of Conservation Targeting Strategies

Resource purchasing funds have become a major tool for environmental protection and resource conservation. These funds use various strategies to target resources for conservation, the choice of which may lead to striking differences in environmental performance. This paper develops an analytical framework to analyze the impact of alternative targeting strategies on different interest groups, including consumers, producers, labor, and environmentalists. We show that ignoring the output price effect of purchasing funds reduces environmental gain and in some cases may make a purchasing fund counterproductive, and we argue that the optimal design of targeting criteria must consider the price feedback effect.