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1.
Optimal regulation of a polluting natural monopolist must correct for both external damages and market power to achieve a social optimum. Existing non-Bayesian regulatory methods require knowledge of the demand function, while Bayesian schemes require knowledge of the underlying cost distribution. We introduce mechanisms adapted to use less information. Our Price-based Subsidy ( PS) mechanisms give the firm a transfer that matches or approximates the incremental surplus generated each period. The regulator need not observe the abatement activity or know the demand, cost, or damage functions of the firm. All of the mechanisms induce the firm to price at marginal social cost, either immediately or asymptotically. 相似文献
2.
Hotelling's r-percent rule does not hold for monopoly extractors of durable exhaustible resources. An example with a nondurable resource in which the rule also fails to hold is presented. An economy with a fixed average propensity to save is modelled. The monopoly extractor recognizes that resource extraction, by affecting output and hence capital accumulation, affects future demand. The firm exploits this effect by causing the marginal profitability of extraction to grow faster or slower than the rate of interest, depending upon initial conditions. Conditions are developed under which the growth rate will be less than the interest rate. 相似文献
3.
I analyze the pricing and investment behavior of a firm that signals the environmental attributes of its production technology through its price to uninformed environmentally conscious consumers. I then analyze the effect of change in environmental regulation on the signaling outcome and the firm's ex ante incentive to invest in cleaner technology. When regulation is weak, a firm signals cleaner technology through higher price; in this case, the firm earns lower profit when it has cleaner technology and thus, has no incentive to invest in cleaner technology. The price charged by the clean firm declines sharply beyond a critical level of regulation. When regulation is sufficiently stringent, the firm with cleaner technology charges lower price but earns higher signaling profit, and ex ante the firm has positive incentive to invest in cleaner technology. With weak regulation, the incentive of the firm to directly disclose its environmental performance rather than signal it through price is increasing in the level of regulation; the opposite holds when regulation is sufficiently stringent. 相似文献
4.
I analyze the pricing and investment behavior of a firm that signals the environmental attributes of its production technology through its price to uninformed environmentally conscious consumers. I then analyze the effect of change in environmental regulation on the signaling outcome and the firm's ex ante incentive to invest in cleaner technology. When regulation is weak, a firm signals cleaner technology through higher price; in this case, the firm earns lower profit when it has cleaner technology and thus, has no incentive to invest in cleaner technology. The price charged by the clean firm declines sharply beyond a critical level of regulation. When regulation is sufficiently stringent, the firm with cleaner technology charges lower price but earns higher signaling profit, and ex ante the firm has positive incentive to invest in cleaner technology. With weak regulation, the incentive of the firm to directly disclose its environmental performance rather than signal it through price is increasing in the level of regulation; the opposite holds when regulation is sufficiently stringent. 相似文献
5.
The objective of the study was to investigate and develop new alternative approaches to effectively meeting the federal SOx and particulate ambient air quality standards at cost savings. Since air pollution control costs would very likely be passed along to the consumer, it is in the best interests of the consumer and industry to find the least-cost alternative policies. Cost-sharing possesses advantages not shared by other control schemes, such as emissions taxes, auctioning of “pollution certificates,” or other methods. The results of this paper indicate that the cost-sharing approach is useful for particulates control in order to minimize the burden of plants already performing substantial control who may require significant added capital investment beyond their initial amount. For SO ξ emissions control the cost-sharing analysis calculations show significant savings in nearly all situations, whether or not stack gas treatment methods were assumed available. Furthermore, the cost-sharing approach may allow further savings when the particular cost requirements of an individual firm differ substantially from the average engineering cost estimates. A cost-sharing option should thus be included in implementation plans as an option to be used by industries at their own initiative. The spatial characteristics of emissions resulting from a particular application of the cost-sharing approach are considered. A spatial airshed emissions allocation model is discussed as a useful method of evaluating cost sharing. 相似文献
6.
Background In ecophysiology and ecotoxicology, gastropods are important both as target organisms for molluscicides and non-target organisms for environmental pollutants or other environmental stressors. With respect to both aspects, biomarkers are investigated at different levels of biological organization in order to understand mechanisms which enable gastropods to cope with or even to benefit from unfavourable environmental conditions. Main topics The paper focuses on the ecotoxicological and ecophysiological work of the author on gastropods which will be reviewed in the context of the state of knowledge in this field of research. In addition to cellular aspects in biomarker research, also biochemical responses of snails to environmental stress (stress proteins, metallothioneins, and metabolic enzymes) will be addressed. Conclusions The paper highlights the suitability of terrestrial and aquatic gastropods as sensitive indicators of environmental stress induced by chemicals or other non-chemical factors. Biomarker studies have been shown not only to be applicable in environmental risk assessment but also to provide fundamental and background knowledge necessary to understand correlations of responses at different levels of biological organization. Recommendations and perspectives A standardized toxicity test with the grapevine snail (ISO 15952) has been established for toxicity assessment in terrestrial habitats. However, freshwater gastropods display a high sensitivity as well, e.?g. to endocrine disrupters, and should be incorporated into future standardized assays for aquatic toxicity testing on the basis of existing knowledge. 相似文献
7.
First-best pricing or assignment of property rights for rival and non-excludable goods is often infeasible. In a setting where the social planner cannot limit total use, we show that common-property resources can be over or under-consumed. This depends on whether the external benefits of reallocating users to less congested resources outweigh the additional costs imposed by new entrants. Importantly, we show that it may be optimal to encourage consumption of some common property resources. Our results have important implications for settings ranging from fisheries and forestry to recreational demand and transportation. 相似文献
8.
The distribution of reproductive success within societies is a key determinant of the outcomes of social evolution. Attempts to explain social diversity, therefore, require that we quantify reproductive skews and identify the mechanisms that generate them. Here, we address this priority using life history and genotypic data from >600 individuals in 40 wild groups of the cooperatively breeding white-browed sparrow weaver, Plocepasser mahali. We show that groups comprise up to six males and seven females, but within-group reproduction is completely monopolised by a single dominant male and female, while extra-group males sire 12–18 % of offspring. Strong within-group kin structure could frequently explain these monopolies, as subordinates had typically delayed dispersal from their natal groups and so frequently (1) lacked within-group outbreeding partners, and/or (2) stood to gain little from contesting dominant reproduction, being almost as related to the dominant’s young as they would have been to their own. Kin structure alone cannot account entirely for these monopolies, however, as they remained complete following the immigration of unrelated males and females. That subordinate females remain reproductively quiescent despite also showing comparable body condition to dominants, overlapping them substantially in age, and showing no evidence of elevated stress hormone levels raises the possibility that they exercise reproductive restraint due instead to a threat of action by dominants and/or deficits in offspring fitness that might arise if subordinates bred. Our findings highlight the complexity of the mechanisms that generate reproductive disparities in animal societies and the challenge of identifying them when skews are complete. 相似文献
9.
Background, aim, and scope In order to assess the effects of social change from the point of view of sustainability the article considers demographic, social and cultural developments. Taking the sectors ‘Building and Housing’, ‘Infrastructure Systems’ and ‘Mobility and Transport’ as examples, it outlines visible trends and describes the possible scope for actions and instruments to achieving sustainably social change. Main features Demographic change, social-cultural change, extent of social change in Schleswig-Holstein, the sectors ‘Building and Housing’, ‘Infrastructure Systems’, and ‘Mobility and Transport’, environmental impact of social change. Results From the point of view of sustainability the essential kriterion is not so much the size of the population in absolute terms as consumer habits, which are subject to numerous influences. One important characteristic of the evolution from the industrial to the post-industrial society is a pluralization of lifestyles, with the associated consumption patterns, in sectors relevant to sustainability. Discussion A diversity of technologies is available for reducing the environmental burden. They influence thermal insulation of buildings, electricity and water sparing, domestic appliances and fuel-efficient vehicles with controlled catalytic converters. The use of these technologies rather depends on cultural and economic trends as well as political decisions than on technical feasibility . Conclusions If no actions occur to counteract them, the effects of social change on the environment will be immense. There will be no ‘demographic benefit’, and neither can the sustainability balance of the postmaterialists be considered more favourable than that of people with a materialistic attitude. Recommendations and perspectives Political groups should address the problems raised by social change, analyze their effects and initiate a comprehensive social process of dialogue and agreement with the players concerned. Quick solutions are not to be expected, since the complexity of the subject, the different interests involved and the large numbers of issues to be regulated require perseverance and a time frame that goes beyond a single legislative period. 相似文献
10.
Keeping track of social interactions among conspecifics is a driving force for the evolution of social cognition. How social cognition, such as social knowledge, ties in with a species' social organization is, however, largely unexplored. We investigated the social knowledge of wild Guinea baboons ( Papio papio) ranging in Senegal, a species that lives in a fluid multilevel society with overlapping habitat use. Using playback experiments, we tested how adult males differentiate between subjects from their own vs. a neighboring or a stranger social unit (“gang”) and assessed ranging patterns with Global Positioning System (GPS) data. While territorial species usually differentiate between group and nongroup members and often respond more strongly to strangers than neighbors (the “dear enemy” effect), subjects in this highly tolerant species should largely ignore other unit members and mainly attend to subjects from their own unit. Males responded strongly after playback of calls recorded from members of their own gang, while they attended only briefly to neighbor or stranger calls. Apparently, males benefit from monitoring the social maneuvers in their own social unit, while it remains to be resolved whether they are unmotivated or unable to keep track of the identities and actions of individuals outside their own gang. The study highlights how the allocation of social attention is tuned to the specifics of a species' social organization, while a complex social organization does not necessarily translate into the need for more elaborate social knowledge. 相似文献
11.
A growing awareness of increasing trends in coastal erosion and flooding due to climate change is triggering a demand for the rapid assessment of the potential responses of the coastlines around the world, principally in locations where human occupation is especially endangered. Investigations of present and future physical vulnerability and associated social risk have, therefore, become crucial for coastal management. In order to provide a quick and simple methodology for the identification of vulnerable coastal segments, Sharples ( 2006) has proposed a mapping methodology, called the smartline approach, which consists of representing, by means of simple lines, a geomorphic classification of the hinterland, backshore and beaches. The aim of this paper is to apply the smartline approach to coastal vulnerability assessment with inclusion of social data. The results show that this methodology is appropriate for the indication of coastal segments with varying degrees of vulnerability to erosion and flooding and for the appraisal of the resulting social risk. 相似文献
12.
Ground-dwelling sciurids exhibit a continuum of sociality and several models predict levels of sociality within this taxon. Models of ground squirrel sociality predict round-tailed ground squirrels ( Xerospermophilus tereticaudus) to be solitary; however, previous behavioral studies suggest round-tailed ground squirrels have a matrilineal social structure. To resolve this discrepancy, we combined behavioral observations with genetic analyses of population structure. We assessed levels of agonistic and amicable behaviors combined with fine-scale population genetic structure of round-tailed ground squirrels in a multi-year study in AZ. Only 45 agonistic and 40 amicable interactions were observed between adults in over 137 h of observations. Overall rates of agonistic or amicable interactions between adults were low (≤0.69/h), with no relationship between relatedness of individuals and rates of either amicable or agonistic interactions. Interactions between juvenile littermates were predominantly amicable. Population substructure was not evident with Bayesian analyses, global or pairwise F ST values; average relatedness among females was not different from males. However, in 2006, the year after a population reduction through targeted animal elimination, a population bottleneck was detected within at least five of seven loci. Contrary to previous behavioral studies, this population of round-tailed ground squirrels, although aggregated spatially, did not exhibit high levels of social behavior nor subpopulation genetic structure. Analyses of the genetic relationships and sociality along a continuum, particularly within aggregates of individuals, may lead to insights into the origin and maintenance of social behaviors by elucidating the mechanisms by which aggregates with intermediate social levels are formed and maintained. 相似文献
13.
The rapid urbanization of the Earth has led to highly populated cities that act as concentrated centers of anthropogenic stressors on the environment. Much of these stressors originate from nonlinear coupling between man-made urban elements (i.e., networks of engineering and socio-economic infrastructures) and the natural environment. An urban area can be treated as a system of urban elements (or elemental systems), and simple interactions between the latter may lead to complex outcomes, known as emergent properties, in the former. Emergent properties of urban systems play an important role in determining their resilience and sustainability, studies on which require an in-depth knowledge of dynamics, interdependencies and feedbacks of urban elements as well as development of quantitative holistic models to integrate such knowledge to predict the overall system response. To facilitate this demanding effort, it is proposed to initiate a new sub-discipline within the discipline of Earth System Engineering, with the portmanteau of Polimetrics, to deal with quantitative scientific aspects of urban systems. This paper discusses two examples of polimetrics related to urban fluid flows. The first deals with the urban heat island and the other with storm surges in coastal cities. 相似文献
14.
Many authors have proposed mechanisms to induce regulated polluting firms to truthfully reveal their private information. This paper proposes an alternative scheme in which the regulator offers each firm a menu of linear price-quantity contracts; faced with this menu, each firm′s dominant strategy is to truthfully report its private information and self-select the contract that is ex post efficient. The proposed menu schedule that is more elastic than the firm′s residual marginal damage function engenders a positive quantity effect, thereby counterbalancing the firm′s incentive to misreport prompted by the linearity of price. Due to its built-in price quantity structure, the scheme performs as designed regardless of the elasticities of marginal damage and demand functions. 相似文献
15.
Animal aggregations are widespread in nature and can exhibit complex emergent properties not found at an individual level. We investigate one such example here, collective vortex formation by congeneric spadefoot toad tadpoles: Spea bombifrons and Spea multiplicata. Tadpoles of these species develop into either an omnivorous or a carnivorous (cannibalistic) morph depending on diet. Previous studies show that S. multiplicata are more likely to develop into omnivores and feed on suspended organic matter in the water body. The omnivorous morph is frequently social, forming aggregates that move and forage together and form vortices in which they adopt a distinctive slowly rotating circular formation. This behaviour has been speculated to act as a means to agitate the substratum in ponds and thus could be a collective foraging strategy. Here we perform a quantitative investigation of the behaviour of tadpoles within aggregates. We found that only S. multiplicata groups exhibited vortex formation, suggesting that social interactions differ between species. The probability of collectively forming a vortex, in response to introduced food particles, increased for higher tadpole densities and when tadpoles were hungry. Individuals inside a vortex moved faster and exhibited higher (by approximately 27%) tailbeat frequencies than those outside the vortex, thus incurring a personal energetic cost. The resulting environmental modification, however, suggests that vortex behaviour may be an adaptation to actively create and exploit a resource patch within the environment. 相似文献
16.
We develop a biologically correct cost system for production systems facing invasive pests that allows the estimation of population dynamics without a priori knowledge of their true values. We apply that model to a data set for olive producers in Crete and derive from it predictions about the underlying population dynamics. Those dynamics are compared to information on population dynamics obtained from pest sampling with extremely favorable results. 相似文献
17.
We develop a biologically correct cost system for production systems facing invasive pests that allows the estimation of population dynamics without a priori knowledge of their true values. We apply that model to a data set for olive producers in Crete and derive from it predictions about the underlying population dynamics. Those dynamics are compared to information on population dynamics obtained from pest sampling with extremely favorable results. 相似文献
18.
The efficient structure of pollution tax policy is examined when it is recognized that enforcing compliance will be costly. There are two components of this cost: (1) the direct cost of enforcement and (2) the cost polluters incur avoiding enforcement. Considering only the first cost, the efficient pollution policy calls for a tax in excess of that conventionally recommended as efficient, T1 but with little enforcement. Once avoidance cost is recognized the efficient policy can be substantially altered; requiring a tax lower than T1, but with greater enforcement. Even when direct enforcement cost is zero, it is shown that there is no unique advantage to T1 in the absence of avoidance cost. 相似文献
19.
Environmental and social factors are critical to determine the timing and duration of lekking behavior since they provide species with signs to maximize benefits over costs in sexual displays. However, these factors have rarely been studied under different environmental conditions, and thus, it remains unclear whether exogenous factors affecting group displays show a general species-specific pattern or whether they are population-specific. Using audio-trapping techniques, we compared factors influencing the daily occurrence and duration of lekking behavior in two populations of Hyla molleri and two populations of Hyla meridionalis located at the thermal extremes (coldest vs. hottest) of their Iberian distribution range. From 12,240 hourly recordings over one season, multimodel inference revealed that the major determinants of chorus occurrence were similar between populations and species (i.e., chorus size the previous day, daytime air temperature, relative humidity, and barometric pressure), and accounted for 51–79 % of its deviance. In contrast, the major determinants of chorus duration differed between populations and species (i.e., chorus size, number of day, and air temperature and relative humidity at the onset of the chorus), and accounted for 38–69 % of its variance. Our findings suggest that the decision making related to lek attendance is environment-dependent, takes place at time between lekking events, and is associated with exogenous factors that may be both stable across species ranges and population-specific when populations are under different climatic conditions. This intraspecific variation might be underlain by plasticity mechanisms providing tree frogs with means to cope with changing environments. Moreover, social facilitation related to male-male acoustic competition seems to play a relevant role on the daily time invested by males in lek attendance. 相似文献
20.
Burning fossil fuels account for over 75% of global greenhouse gas emissions and over 90% of carbon dioxide emissions, calling for alternative fuels such as hydrogen. Since the hydrogen demand could reach 120 million tons in 2024, efficient and large-scale production methods are required. Here we review electrocatalytic water splitting with a focus on reaction mechanisms, transition metal catalysts, and optimization strategies. We discuss mechanisms of water decomposition and hydrogen evolution. Transition metal catalysts include alloys, sulfides, carbides, nitrides, phosphides, selenides, oxides, hydroxides, and metal-organic frameworks. The reaction can be optimized by modifying the nanostructure or the electronic structure. We observe that transition metal-based electrocatalysts are excellent catalysts due to their abundant sources, low cost, and controllable electronic structures. Concerning optimization, fluorine anion doping at 1 mol/L potassium hydroxide yields an overpotential of 38 mV at a current density of 10 mA/cm2. The electrocatalytic efficiency can also be enhanced by adding metal atoms to the nickel sulfide framework. 相似文献
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