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Renewable Resources in an Overlapping Generations Economy Without Capital   总被引:1,自引:0,他引:1  
We incorporate a renewable resource into an overlapping generations model without capital and with quasi-linear preferences. Besides being an input for production the resource serves as a store of value. We characterize the dynamics, efficiency, and stability of the steady-state equilibria. The stability properties are sensitive to the type of resource growth. For constant growth there is only one steady-state equilibrium which is stable and efficient. In the general case of the concave growth function, there are usually at least two steady-state equilibria, one of which is stable and the other one unstable. The unstable steady state is efficient, but the stable one may or may not be. We study the robustness of our results by assuming a logarithmic utility function. We show that for the Cobb–Douglas production function the steady state is unique and stable regardless of whether the equilibrium is efficient or inefficient. Our analytical results are illustrated by numerical calculations.  相似文献   
2.
An environmentally extended input-output (EE-IO) analysis - environmental impacts of material flows caused by the Finnish economy - was carried out in order to improve data on production and consumption in Finland. The study resulted in the ENVIMAT model, which can be used to analyze the relationship between material flows, environmental impacts and the economy. The model is based on monetary and physical input-output tables and an environmental life-cycle impact assessment. This article summarizes the main methodological aspects and findings regarding the material flows and climate impacts caused by the Finnish economy in 2002 and 2005. The Finnish model has relatively detailed input data with 150 industries and 918 products and the data on imports was assessed according to a mixed approach with the help of life-cycle inventory data. The results of the model showed that the Finnish economy uses imported material resources as much as domestic resources. Life-cycle greenhouse gas (GHG) emissions caused by imports were equivalent to 70-80% of domestic emissions. The GHG emissions embodied in imports (emissions abroad) and exports (emissions within Finland) were of the same magnitude. The analysis showed that the service sector accounted for 44% of GHG emissions caused by the domestic final use of products. Analysis of the results also showed that the indicator of total material requirement (TMR) should not be used for environmental impact comparisons of products and services. In the future, the aim is to use the ENVIMAT model for assessing temporal changes in the economy; for monitoring sustainable development; for planning climate change mitigation; and for identifying important factors in the economy and assessing their impacts.  相似文献   
3.
Corruption and forest concessions   总被引:3,自引:0,他引:3  
We examine how corruption impacts a central government's application of concession policy instruments consisting of royalty rates, concession size, environmentally sensitive logging levels, and enforcement. Harvesters have incentives to illegally log by taking more volume than is allowed, high grading through removal of only the highest valued and best formed trees, and shirking environmentally sensitive logging requirements, all of which reduce public goods produced from native tropical forests. Corruption is introduced through logging inspectors who can be bribed by harvesters to avoid fines associated with illegal logging. Both the theory and a simulation are used to compare policy design under corruption and no corruption.  相似文献   
4.
Environmental Science and Pollution Research - For a recirculating aquaculture system (RAS), a passive water treatment system was designed for efficient discharge nutrient removal and water reuse...  相似文献   
5.
This paper studies the impact of harvesting, property, and profit taxes on private rotation age in an ongoing rotations model, where the private landowner is interested not only in the present value of harvest revenue, but also in the private amenity services provided by the forest stand. The main finding of the paper is that conventional wisdom about the rotation effects of forest taxes, distilled from the Faustmann model, predominantly ceases to hold. This is because forest taxes distort the relative profitability of timber and amenity production in a way that is sensitive to the precise nature of amenity valuation. Therefore, the design of forest tax policy necessitates good knowledge of the landowner's objective function concerning the type of amenity services.  相似文献   
6.
This paper presents the results of life cycle inventory (LCI) analyses that were carried out to determine the environmental impacts (emissions, resource extractions and land use) of different newspaper waste management options for the Helsinki Metropolitan Area (HMA). LCI analyses were performed for five product systems, in which discarded newspapers were divided into two streams: separately collected newspapers and newspapers in mixed waste. In all the options, the manufacturing and printing processes of newspaper were kept unchanged. The waste management alternatives included combinations of material recycling, energy recovery and landfilling. These product systems were modelled using the current collection rate of newspaper and four additional collection rates. The LCIs of the product systems showed that the life cycle phase causing the most environmental impacts was the paper mill. When comparing the different waste management systems, the energy recovery options were in general superior to landfilling. The ecological implications of the increased energy recovery and decreased material recycling of newspaper were, however, not yet considered in the study. These aspects were assessed in the life cycle impact assessment (LCIA), which was performed after the LCI phase.  相似文献   
7.
Endemic hantavirus infection impairs the winter survival of its rodent host   总被引:1,自引:0,他引:1  
The influence of pathogens on host fitness is one of the key questions in infection ecology. Hantaviruses have coevolved with their hosts and are generally thought to have little or no effect on host survival or reproduction. We examined the effect of Puumala virus (PUUV) infection on the winter survival of bank voles (Myodes glareolus), the host of this virus. The data were collected by monitoring 22 islands over three consecutive winters (a total of 55 island populations) in an endemic area of central Finland. We show that PUUV infected bank voles had a significantly lower overwinter survival probability than antibody negative bank voles. Antibody negative female bank voles from low-density populations living on large islands had the highest survival. The results were similar at the population level as the spring population size and density were negatively correlated with PUUV prevalence in the autumn. Our results provide the first evidence for a significant effect of PUUV on host survival suggesting that hantaviruses, and endemic pathogens in general, deserve even more attention in studies of host population dynamics.  相似文献   
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