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1.
This article analyzes the effect of market power in the presence of dynamic and biological externalities. When several countries harvest fish in international waters the evolution of fish population is affected by their joint action, thus generating a biological and a dynamic externality. If there is trade, the market-clearing prices depend on the harvesting and consumption in all countries. Therefore, market-clearing prices also generate an externality. We find a subgame perfect Cournot–Nash equilibrium and study the conditions under which it may be efficient. We also analyze the role of different externalities in generating inefficiency.  相似文献   

2.
Since the Olympic Games will be held in Beijing at 2008, the urban development plan of Beijing deserves special attention. The essence of regional sustainable development is that population (P), resources (R), environment (E) and economy (E) could develop with sustenance, order and coordination during a certain period, which forms a complex system called the PREE complex system. For this system, a multi-objective integrated model is formulated and solved by a nonlinear goal programming technique. Beijing's PREE complex system is then used as an empirical study. Twelve interesting goals are carefully selected, the parameters of each goal function were estimated by using Beijing's 50-year (1949–1999) statistical data, and their ideal goal limits for 2000 and 2005 are chosen according to the 9th and 10th Five-Year Economic Development Plans of Beijing. The results showed that population size is the most sensitive element in Beijing's PREE complex system. Furthermore, some suggestions related to public policies about the urban development of Beijing are proposed.  相似文献   

3.
The design of marine reserves is complex and fraught with uncertainty. However, protection of critical habitat is of paramount importance for reserve design. We present a case study as an example of a reserve design based on fine-scale habitats, the affinities of exploited species to these habitats, adult mobility, and the physical forcing affecting the dynamics of the habitats. These factors and their interaction are integrated in an algorithm that determines the optimal size and location of a marine reserve for a set of 20 exploited species within five different habitats inside a large kelp forest in southern California. The result is a reserve that encompasses approximately 42% of the kelp forest. Our approach differs fundamentally from many other marine reserve siting methods in which goals of area, diversity, or biomass are targeted a priori. Rather, our method was developed to determine how large a reserve must be within a specific area to protect a self-sustaining assemblage of exploited species. The algorithm is applicable across different ecosystems, spatial scales, and for any number of species. The result is a reserve in which habitat value is optimized for a predetermined set of exploited species against the area left open to exploitation. The importance of fine-scale habitat definitions for the exploited species off La Jolla is exemplified by the spatial pattern of habitats and the stability of these habitats within the kelp forest, both of which appear to be determined by ocean microclimate.  相似文献   

4.
We examine the influence of risk attitudes on the provision of an externality and on the proper size of Pigouvian correction when the externality is a random variable whose distribution is affected by an observable externality-generating activity. An intervening technology relates changes in this observable activity to the probability distribution of the relevant externality. Unlike the now-standard result in the theory of the firm involving the influence of risk attitudes on output levels, we cannot conclude that increases in risk aversion will lead necessarily to a reduction in the level of the externality. Our results are applied to a wide range of market failures.  相似文献   

5.
Regulator reputation, enforcement, and environmental compliance   总被引:1,自引:0,他引:1  
This paper explores empirically the impact of enforcement efforts on environmental compliance, focusing on the role of regulator reputation spillover effects. We find that, on the margin, the impact of a fine for water pollutant violations is about a two-thirds reduction in the statewide violation rate in the year following a fine. This large result obtains through the regulator's enhanced reputation; the deterrence impact on other plants in a state is almost as strong as the impact on the sanctioned plant. Focusing only on the response of the sanctioned plant, as in previous studies, may therefore seriously underestimate the efficacy of fines and other sanctions. This paper also examines the relative effectiveness of monitoring and enforcement instruments. Non-monetary sanctions contribute no detected impact on compliance, and the marginal fine induces substantially greater compliance than the marginal inspection.  相似文献   

6.
This paper estimates the impact of climate change on the prevalence of criminal activity in the United States. The analysis is based on a 30-year panel of monthly crime and weather data for 2997 US counties. I identify the effect of weather on monthly crime by using a semi-parametric bin estimator and controlling for state-by-month and county-by-year fixed effects. The results show that temperature has a strong positive effect on criminal behavior, with little evidence of lagged impacts. Between 2010 and 2099, climate change will cause an additional 22,000 murders, 180,000 cases of rape, 1.2 million aggravated assaults, 2.3 million simple assaults, 260,000 robberies, 1.3 million burglaries, 2.2 million cases of larceny, and 580,000 cases of vehicle theft in the United States.  相似文献   

7.
Abstract

Due to vast research programmes of industrial countries during the last two decades, our knowledge about the intrinsic properties of nanomaterials has increased considerably. However, ‘nanoregulation’ lags behind this progress. Key elements of nanoregulation are definition/scope and safety/consumer information. Safety information along the nano life-cycle is vital for the nanoparticle producer down to the industrial downstream user (product producer). However, nanodeclaration (in the sense of a label on the product for consumers) is not yet widely spread, in different geographic regions for different reasons. This is a case study for the EU, Switzerland, Thailand, the USA, and Intergovernmental Organisations. In addition, this study investigates inter- and governmental activities and the relationship between nanodeclaration and WTO rules. Non-compliance with WTO rules is a pretext for not introducing nanodeclaration in products. It is concluded that WTO rules do not exclude nanodeclaration.  相似文献   

8.
International externalities, strategic interaction, and domestic politics   总被引:1,自引:0,他引:1  
Domestic politics can sometimes play an influential role when externalities have strategic and international implications. If voters delegate the choice to policymakers and if individual countries independently determine their environmental policy using a consumption tax on the emissions generating good, the result could be an outcome that is inferior to the one preferred by the median voter in the absence of delegation. On the other hand, if the international externality is unilateral in nature, rather than reciprocal, we find that delegation is largely irrelevant, since voters’ choice of policymaker is no longer strategic in character. Similarly, if voters anticipate policymakers successfully coordinating their policies at a later stage, there also will be no difference between the policymakers’ and the median voters’ aggregate weighting of environmental emissions.  相似文献   

9.
Phylogeny, niches, and relative abundance in natural communities   总被引:3,自引:0,他引:3  
Kelly CK  Bowler MG  Pybus O  Harvey PH 《Ecology》2008,89(4):962-970
Community structure refers to the number of species in a community and the pattern of distribution of individuals among those species. We use a novel way of representing community structure to show that abundance within closely related pairs of co-occurring tree species in a highly diverse Mexican forest is more equitable than is abundance within more distantly related pairs. This observation is at odds with the fundamental assumption of neutral models of community structure, i.e., that species are interchangeable. The observed patterns suggest niche apportionment, in which interaction is focused pairwise between congeners but falls away from the phylogenetic structure above the genus level. Thus niche processes may significantly affect community structure through regulating relative abundance in a substantial proportion of species, which in turn potentially enhances community stability. One such mechanism of stable coexistence has already been shown to be active in this forest.  相似文献   

10.
This paper examines climate-change benefit-cost analysis in the presence of scientific uncertainty in the form of ambiguity. The specific issue addressed is the robustness of benefit-cost analyses of climate-change policy alternatives to relaxation of Savage's original axioms. Two alternatives to subjective expected utility (SEU) are considered: maximin expected utility (MEU) and incomplete expected utility (IEU). Among other results, it is demonstrated that polar opposite recommendations can emerge in an ambiguous decision setting even if all agree on Society's rate of time preference, Society's risk attitudes, the degree of ambiguity faced, and the scientific primitives. We show that, for a simple numerical simulation of our model, an MEU decision maker favors policies which immediately tackle climate change while an IEU decision prefers “business as usual”.“Each agency shall assess the costs and benefits of the intended regulation, and recognizing that some costs and benefits are difficult to quantify, propose or adopt a regulation only upon a reasoned determination that the benefits of the intended regulation justify its cost.” Executive Order 12866 of the US President.  相似文献   

11.
Abstract:  Debate about the nature and appropriateness of advocacy by environmental scientists is important—it represents understanding the role of these citizens in our society. Much has been written about advocacy by scientists, and that literature describes substantial diversity in reasons why advocacy by scientists is or is not appropriate. Despite the nature of this literature there has been no comprehensive, systematic review of why some favor and others oppose advocacy by environmental scientists. Through a literature review we catalogued, categorized, and critiqued the arguments used for and against the appropriateness of advocacy by environmental scientists. Most arguments, whether for or against advocacy, are characterized by some significant deficiency. From our analysis of the literature an argument emerges that to date has never been fully articulated: that advocacy is nearly unavoidable, and that scientists, by virtue of being citizens first and scientists second, have a responsibility to advocate to the best of their abilities, to improve their advocacy abilities, and to advocate in a justified and transparent manner. We also discuss the meaning and relevance of advocacy being justified and transparent. We suggest scientists expend their efforts to better understand what constitutes appropriate advocacy and spend less effort pondering whether they should advocate .  相似文献   

12.
Stochastic Pollution, Permits, and Merger Incentives   总被引:1,自引:0,他引:1  
Pollution permit regulations introduce nonlinearities into the objective function of a polluting firm. We develop a microeconomic model to show the effects these nonlinearities might have upon firm decisions when emissions are stochastic. Under perfect competition the fraction of planned pollution covered by permits is shown to be separable from planned production. We also demonstrate that permit management incentives may motivate a merger of otherwise independent firms. Incentives to petition for “bubble” coverage are also considered. The model is studied under risk neutrality and risk aversion. Imperfectly competitive situations in the output and permit markets are also analyzed.  相似文献   

13.
Wildlife management is limited by uncontrolled and often unrecognized environmental variation, by limited capabilities to observe and control animal populations, and by a lack of understanding about the biological processes driving population dynamics. In this paper I describe a comprehensive framework for management that includes multiple models and likelihood values to account for structural uncertainty, along with stochastic factors to account for environmental variation, random sampling, and partial controllability. Adaptive optimization is developed in terms of the optimal control of incompletely understood populations, with the expected value of perfect information measuring the potential for improving control through learning. The framework for optimal adaptive control is generalized by including partial observability and non-adaptive, sample-based updating of model likelihoods. Passive adaptive management is derived as a special case of constrained adaptive optimization, representing a potentially efficient suboptimal alternative that nonetheless accounts for structural uncertainty.  相似文献   

14.

The global amount of solid waste has dramatically increased as a result of rapid population growth, accelerated urbanization, agricultural demand, and industrial development. The world's population is expected to reach 8.5 billion by 2030, while solid waste production will reach 2.59 billion tons. This will deteriorate the already strained environment and climate situation. Consequently, there is an urgent need for methods to recycle solid waste. Here, we review recent technologies to treat solid waste, and we assess the economic feasibility of transforming waste into energy. We focus on municipal, agricultural, and industrial waste. We found that methane captured from landfilled-municipal solid waste in Delhi could supply 8–18 million houses with electricity and generate 7140 gigawatt-hour, with a prospected potential of 31,346 and 77,748 gigawatt-hour by 2030 and 2060, respectively. Valorization of agricultural solid waste and food waste by anaerobic digestion systems could replace 61.46% of natural gas and 38.54% of coal use in the United Kingdom, and could reduce land use of 1.8 million hectares if provided as animal feeds. We also estimated a levelized cost of landfill solid and anaerobic digestion waste-to-energy technologies of $0.04/kilowatt-hour and $0.07/kilowatt-hour, with a payback time of 0.73–1.86 years and 1.17–2.37 years, respectively. Nonetheless, current landfill waste treatment methods are still inefficient, in particular for treating food waste containing over 60% water.

  相似文献   

15.
In practice, complete demand systems are not estimated. Rather, either an incomplete demand system is estimated, or separability is invoked and a partial demand system is estimated. This paper considers the relationship between the conventional compensating variation (equivalent variation) and the corresponding welfare measure that can be derived from a partial demand system and the current budget allocation to the separable group. Even assuming the separability assumption invoked is appropriate, these partial measures provide, in general, only a limited amount of information about the compensating variation and no information about the equivalent variation. Great care is therefore needed when using partial welfare measures to evaluate policy.  相似文献   

16.
Environmental Geochemistry and Health - Perchlorate (ClO4?) has been identified as a persistent environmental contaminant of concern. Perchlorate exposure is a potential health concern...  相似文献   

17.
Climatic Change, Wildfire, and Conservation   总被引:11,自引:0,他引:11  
Abstract:  Climatic variability is a dominant factor affecting large wildfires in the western United States, an observation supported by palaeoecological data on charcoal in lake sediments and reconstructions from fire-scarred trees. Although current fire management focuses on fuel reductions to bring fuel loadings back to their historical ranges, at the regional scale extreme fire weather is still the dominant influence on area burned and fire severity. Current forecasting tools are limited to short-term predictions of fire weather, but increased understanding of large-scale oceanic and atmospheric patterns in the Pacific Ocean (e.g., El Niño Southern Oscillation, Pacific Decadal Oscillation) may improve our ability to predict climatic variability at seasonal to annual leads. Associations between these quasi-periodic patterns and fire occurrence, though evident in some regions, have been difficult to establish in others. Increased temperature in the future will likely extend fire seasons throughout the western United States, with more fires occurring earlier and later than is currently typical, and will increase the total area burned in some regions. If climatic change increases the amplitude and duration of extreme fire weather, we can expect significant changes in the distribution and abundance of dominant plant species in some ecosystems, which would thus affect habitat of some sensitive plant and animal species. Some species that are sensitive to fire may decline, whereas the distribution and abundance of species favored by fire may be enhanced. The effects of climatic change will partially depend on the extent to which resource management modifies vegetation structure and fuels.  相似文献   

18.
Geomorphological and sedimentological studies were carried out along the Garigliano and Elis littorals with the aim to highlight if similar geoenvironmental features are controlled by same coastal processes. Actually, both sites are in Mediterranean climate regions very far each other, modeled by western winds and storms, characterized by wide sandy coastal dunes parallel to the present shoreline, with abundant pumices, and locally anthropized. The Garigliano littoral is characterized by Holocene dune and Pleistocene aeolian deposits. The beach is bounded landwards by a dune system emplaced during the Holocene. Geoarchaeological surveys highlighted the presence of a Roman road which cut the dune, with age older than Graeco-Roman Period. Since the end of the 1950’s, strong littoral retreat affected the beach-dune system, partly due to human activity. The coastland of Elis is characterized by Quaternary marine deposits. Three significant morphogenetic phases occurred during the Holocene. During the last phase, from Graeco-Roman Period to current, shoreline retreat and deposition of aeolian sands occurred. Geoarchaeological evidences suggest that this phase is related to a sea-level lowstand followed by a slow sea-level rise up to the present position, and by humid-temperate climate. Geomorphological surveys of the dunes of Garigliano and Elis, each other compared, suggest that the main phases of their development are related to the effects of climatic conditions, sea-level changes, and secondly to the recent anthropization. The coarse pumices found on both beaches of Campania and Peloponnese regions show the same mineralogical and petrographic features, so we assumed that they likely originated from the Aeolian Arc, southern Italy, which have same composition. These pumices reached the studied coasts by flotation, under the influence of winds and marine surface currents from the southwest-southeast and northwest-west respectively, participating to local coastal processes and representing a good geoindicator of long-distance drift. Precisely for these morphologically converging aspects, such distant sites have been selected and compared.  相似文献   

19.
Vertebrate animals can be injured or threatened with injury through human activities, thus warranting their “rescue.” Details of wildlife rescue, rehabilitation, release, and associated research (our 4 Rs) are often recorded in large databases, resulting in a wealth of available information. This information has huge research potential and can contribute to understanding of animal biology, anthropogenic impacts on wildlife, and species conservation. However, such databases have been little used, few studies have evaluated factors influencing success of rehabilitation and/or release, recommended actions to conserve threatened species have rarely arisen, and direct benefits for species conservation are yet to be demonstrated. We therefore recommend that additional research be based on data from rescue, rehabilitation, and release of animals that is broader in scope than previous research and would have community support.  相似文献   

20.
Kendall BE  Fox GA  Fujiwara M  Nogeire TM 《Ecology》2011,92(10):1985-1993
Demographic heterogeneity--variation among individuals in survival and reproduction--is ubiquitous in natural populations. Structured population models address heterogeneity due to age, size, or major developmental stages. However, other important sources of demographic heterogeneity, such as genetic variation, spatial heterogeneity in the environment, maternal effects, and differential exposure to stressors, are often not easily measured and hence are modeled as stochasticity. Recent research has elucidated the role of demographic heterogeneity in changing the magnitude of demographic stochasticity in small populations. Here we demonstrate a previously unrecognized effect: heterogeneous survival in long-lived species can increase the long-term growth rate in populations of any size. We illustrate this result using simple models in which each individual's annual survival rate is independent of age but survival may differ among individuals within a cohort. Similar models, but with nonoverlapping generations, have been extensively studied by demographers, who showed that, because the more "frail" individuals are more likely to die at a young age, the average survival rate of the cohort increases with age. Within ecology and evolution, this phenomenon of "cohort selection" is increasingly appreciated as a confounding factor in studies of senescence. We show that, when placed in a population model with overlapping generations, this heterogeneity also causes the asymptotic population growth rate lambda to increase, relative to a homogeneous population with the same mean survival rate at birth. The increase occurs because, even integrating over all the cohorts in the population, the population becomes increasingly dominated by the more robust individuals. The growth rate increases monotonically with the variance in survival rates, and the effect can be substantial, easily doubling the growth rate of slow-growing populations. Correlations between parent and offspring phenotype change the magnitude of the increase in lambda, but the increase occurs even for negative parent-offspring correlations. The effect of heterogeneity in reproductive rate on lambda is quite different: growth rate increases with reproductive heterogeneity for positive parent-offspring correlation but decreases for negative parent-offspring correlation. These effects of demographic heterogeneity on lambda have important implications for population dynamics, population viability analysis, and evolution.  相似文献   

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