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1.
Sustainable management of natural resources, and in particular fisheries, must take into account several conflicting objectives. This is the case in the French Guiana shrimp fishery for which profitability objectives imply a reduction in the fishing activity. On the one hand, this fishery has negative externalities on marine biodiversity due to discards. On the other hand, this fishery has positive externalities on the economy of the local community and interestingly enough on a protected seabird species in the area (the Frigatebird that feeds on discards). In this paper, we examine the viability of that system considering two sustainability objectives: an economic objective in terms of the profitability of the fishing activity, and a conservation objective in terms of the Frigatebird population. For that purpose, we have developed a dynamic model of that bioeconomic system and study here the trade-offs between the two conflicting objectives. It provides a means to quantify the necessary give and takes involving the economic and ecological objectives that would ensure a viable management solution. Our study confirms the relevance of the viability approach to address natural resource management issues, which should lead to the development of new tools for the arbitration of conflicting sustainability objectives. In particular, such tools could be used as a quantitative basis for cost–benefit analysis taking into account environmental externalities.  相似文献   

2.
This paper explores how harvesting technology can affect firms' internalisation of common pool externalities and the incentives for expanding firm's size. Focusing on supply side non-pecuniary externalities, our closed-entry harvesting competition model suggests that when marginal harvesting costs are weakly sensitive to common pool externalities, atomistic competition is likely to remain, other things equal, as the predominant industrial structure in the fishery. The avenue for increasing industrial concentration is modelled via Stackelberg leadership which offers the option of preempting rivals' production. In our static modelling, a fishery subject to Stackelberg signalling results in higher overfishing versus the case of a highly decentralised harvesting sector (proxied by the use of Nash conjectures). Given that static optimising behaviour could be interpreted as a result of entry controls and other fishing regulations being widely perceived as ineffective controls, the obtained overfishing ranking suggests that in fisheries where strategic preemption in production is feasible, but where entry controls and other important regulations on fishing effort are considered to be ineffective, overfishing is likely to remain the predominant outcome, even if other incentives promote evolution towards a more concentrated industry structure. When the fishery is already overpopulated by numerous small firms, whatever advantages large firms may have in terms of profitability, numerous small-scale fishermen tend to make up for in the political arena. This imposes constraints on the politically feasible fishing regulations. We use a second best welfare benchmark to illustrate resulting policy trade-offs.  相似文献   

3.
The history of the management of Baltic fishery resources suggests that both biological and non-biological factors influence management decisions and that both types of information are essential for management which promotes sustainability. There is a direct link between the exploitation level and the risks for fishing as an economic activity due to fluctuations in the resource. This paper analyses the sustainability of the present catch levels of major Baltic fish stocks. By examining the rate of fishing mortality and recruitment variability, the possibility of sustaining present catch levels can be investigated. Current catch levels of Baltic cod and some salmon stocks are not sustainable whereas sprat and herring catches are. High rates of fishing mortality of cod and salmon may endanger stocks if a drop in the recruitment causes an increase of the fishing mortality rates in order to sustain short-term catches. By analysing the trade off between exploitation level and risk of stock decline, managers can obtain a basis for quota negotiations.  相似文献   

4.
A two-agent model for the exploitation of the Arcto-Norwegian cod stock is developed to investigate the economic benefits that can be realized from the resource, and the effect of exploitation on stock sustainability under cooperation and non-cooperation. The two agents are identified in this study as a trawl fishery versus a coastal fishery. Unlike in Munro (1979), where conflicts in the management strategies of agents arise from differences in the perceptions of the discount factor, fishing effort costs, and consumer preferences, here conflicts arise mainly from the differences in fishing gear and grounds, and the age group of cod targeted by the two agents. Using a game theoretic framework, we show that given available data, the optimum optimorum is obtained under cooperation with side payments and no predetermined harvest shares, in which case the coastal fishery buys out the trawl fishery. However, sensitivity analysis shows that if the price premium assumed for mature cod is taken away, the trawl fishery takes over as the producer of the optimum optimorum.  相似文献   

5.
A key element in evaluating fishery management strategies is examining their effects on the economic performance of fishery participants, yet nearly all empirical studies of fisheries focus exclusively on the amount of fish harvested. The economic benefits derived from fish stocks involve the amount of revenue generated from fish processing, which is linked to both the way fish are harvested and the products produced from the fish. In this study we econometrically estimate a flexible revenue function for catcher-processor vessels operating in the Alaskan pollock fishery, recognizing potential endogeneity and a variety of fishing inputs and conditions. We find significant own-price supply responses and product substitutability, and enhanced revenues from increased fishing days and tow duration after a regulatory change introduced property rights through a new fishing cooperative. We also find significant growth in economic productivity, or higher revenues over time after controlling for observed productive factors and price changes, which exceeds that attributable to increased harvest. These patterns suggest that the move to rights-based management has contributed significantly to economic performance in the pollock fishery.  相似文献   

6.
Marine scientists and policymakers are encouraging ecosystem-based fishery management (EBFM), but there is limited guidance on how to operationalize the concept. We adapt financial portfolio theory as a method for EBFM that accounts for species interdependencies, uncertainty, and sustainability constraints. Illustrating our method with routinely collected data available from the Chesapeake Bay, we demonstrate the gains from taking into account variances and covariances of gross fishing revenues in setting species total allowable catches. We find over the period from 1962-2003 that managers could have increased the revenues from fishing and reduced the variance by employing EBFM frontiers in setting catch levels.  相似文献   

7.
Agri-environmental policies in the EU and United States: A comparison   总被引:4,自引:0,他引:4  
Agri-environmental policies (AEPs) in the United States and the European Union are examples of payments for environmental services that pay farmers to reduce the negative externalities of agricultural production, while serving as a means to transfer public funds to farmers. We show that despite similar origins, AEPs in the two regions differ both in their specific objectives and in their implementation. For example, AEPs in most member states of the EU-15 have the additional objective of using agriculture as a driver for rural development. This objective is achieved by compensating farmers for the private delivery of positive public goods, such as attractive landscapes, produced by agriculture. The rationale is market failure, and there is empirical evidence that Europeans are willing to pay for such positive externalities. No comparable provision exists in U.S. policy. By contrast, U.S. AEPs focus almost entirely on reducing agriculture's negative externalities, such as soil erosion. Second, we find that U.S. programs are more targeted than their EU counterparts, and take opportunity cost into account. The EU programs, on the other hand, address a wider range of externalities, and are focused more on the paying for a particular farming process than reducing specific negative externalities. The EU takes a broader view of AEPs than does the United States, both in terms of type of activity that can be funded, and by using less targeting by land characteristics, and so the European program could be more easily used as a mechanism for transferring income to producers. Despite this, we find evidence that many of the amenities targeted by the programs are demanded by the population.  相似文献   

8.
Recent studies have shown that many marine ecosystems are experiencing an accelerating loss of population and biodiversity. It is apparent that there is a growing disparity between the available supply of fish and the desire of the growing world population to catch them. Although studies have begun to question the ecological sustainability of managed fishery systems, they often omit the corresponding effects on the economic sustainability of fishery industries. This is particularly important in rural coastal areas where the fishing industry is often a dominant employer. In this article, we analyze the interactions between economic and ecological dynamic systems using a multi-agent dynamic model of fishery management. Multiple agents (fishers) harvest multiple fish species and adapt the amount and allocation of their effort to their value functions, which are given as net profits of the fish harvest sold for a market price. This is largely unique in fishery models, since many econometric studies view fishers as represented by homogenous ‘average’ agents. We introduce and compare two different decision rules governing the behavior of fishers engaged in a competitive market. We demonstrate a situation where both behaviors lead to a decline of all fish stocks, as well as profits for most fishers. As an alternative, we introduce a cooperative approach in which fisheries jointly set sustainable limits for total harvest and effort that are then distributed to the fishers according to distribution rules. The simulation reveals that fish stocks and profits can stabilize at significantly higher levels in the cooperative case, leading to a continuous accumulation of capital for all fishers. This model demonstrates key aspects of overfishing conflicts that can be overcome through planned fishing quotas and cooperative market mechanisms. It also demonstrates a novel approach for simulating the dynamic behavior of heterogeneous fishers.  相似文献   

9.
Several world fish stocks are being explored at unsustainable levels and require management plans to rebuild stock abundance. Defining a management plan is, however, a complex task that entails multidisciplinary work. In fact, while it requires solid scientific knowledge of fish stocks, the inclusion of economic and social objectives is crucial to a successful management implementation. In this paper we develop an age-structured bioeconomic model where the objective function is modified to accommodate preferences from different stakeholders. In particular, we consider important characteristics that a management plan should take into account: profit maximization, fishermen’s preference for reducing landings’ fluctuations and risk of fishery collapse. Modeling preferences for reducing landings’ fluctuations is accomplished by defining a utility function with aversion to intertemporal income fluctuations. Building upon biology literature, we model precautionary concerns by incorporating a probability of collapse that depends on current spawning biomass. We illustrate how this framework is able to assist in the analysis and design of harvest control rules applying it to the Ibero-Atlantic sardine stock.  相似文献   

10.
This paper sets out to assess the workability of the regulation currently in force in the European anchovy fishery of the VIII division. Particular attention is paid to the importance of the institutional regime in the allocation of natural resources. The study uses a bio-economic approach and takes into account the fact that, not only the European Union and the individual countries involved, but also some of the resource users or appropriators intervene in its management. In order to compare the effectiveness of the rules which, at the various levels, have been set up to restrict exploitation of the resource, the anchovy fishery is simulated in two extreme situations: open access and sole ownership. The results obtained by effective management will then be contrasted with those obtained from the maximum and zero profit objectives related with the two above-mentioned scenarios. Thus, if the real data come close to those derived from the sole ownership model it will have to be acknowledged that the rules at present in force are optimal. If, on the other hand, the situation more closely approach the results obtained from the open access model, we will endeavour in our conclusions to provide suggestions for economic policy measures that might improve the situation in the fishery.  相似文献   

11.
A major problem affecting world fisheries today is overcapacity of which overfishing is both a cause and a consequence. There is a general consensus that fisheries subsidies cause great harm to the resource by exacerbating the problems resulting from the common resource issues of fisheries leading to overexploitation of the resource through a new set of perverse incentives. Many now advocate that subsidies should gradually be terminated, and that capacity enhancing and fuel subsidies should be terminated immediately. On account of the global fisheries crises, highly subsidised fisheries and the anticipated reforms of the European Union's Common Fisheries Policy this study aimed to estimate the impact of eliminating fisheries subsidies on various macro and micro economic variables pertaining to the regional economy of the Azores using a dynamic computable general equilibrium model based on a social accounting matrix. The simulation results suggest that reduction, and in particular, elimination of fisheries subsidies would have a substantial effect on the region, however, the negative social and economic effects would be largely confined to the fishing sector. Conversely, the augmentation of fishery subsidies would benefit the fishing sector with an overall adverse effect on the rest of the economy.  相似文献   

12.
We present an analysis of quota regulation and discarding in multispecies fisheries, explicitly taking into account the costs of non-compliance with quotas and a possible discard ban, as well as the costs of selective fishing (avoidance effort). We examine the impact of a discard ban on vessels’ profit maximising behaviour, in particular where species quotas are not set in proportion to their availability on the fishing grounds, considering both non-tradeable quotas and ITQs. We show the interdependence between penalty rates for both discards and over-quota landings in determining quota market outcomes. We find that quota prices are sensitive to penalty rates and to the presence of restrictive quotas for “choke” species.  相似文献   

13.
The incorporation of the intergenerational equity objective has rendered the traditional Cost–Benefit Analysis (CBA) approach obsolete for the evaluation of projects presenting an important number of environmental externalities and for those whose impacts extend throughout a long period of time.Based on the assumption that applying a discount rate rewards current consumption and, therefore, that it is only possible to introduce a certain intergenerational equity in a Cost–Benefit Analysis, in this work we propose an approach to discounting based on a different rationale for tangible and intangible effects. We designed two indicators of environmental profitability: a) the Intergenerational Transfer Amount (ITA), which quantifies in monetary units what the current generation is willing to pass on future generations when an environmental restoration project is carried out, and b) the Critical Environmental Rate (CER), measures the implicit environmental profitability.These concepts were tested through an empirical case study pertaining to the assessment of an Erosion Control Project in the southeast of Spain. The results yield traditional profitability indicators that are higher — and probably closer — to the real values set by the contemporary society. The information provided by the environmental profitability indicators proposed renders more transparency to the quantification of the levels of intergenerational equity applied, thereby facilitating the difficult reconciliation of the CBA technique with the objective of sustainability.  相似文献   

14.
The paper puts forward a model of the Atlantic salmon fishery in the Baltic Sea that integrates the salient biological and economic characteristics of migratory fish stocks. Designed to be compatible with the framework used for actual stock assessments, the model accounts for age-structured population dynamics, the seasonal harvest and competing harvesting by commercial and recreational fishermen. It is parameterized for the Simojoki River stock. The socially optimal policy for maximizing discounted net benefits from the fishery within an uncertain environment is determined using a dynamic programming approach and numerical solution method. Our results indicate that substantial economic benefits could be realized under optimal management without compromising stock sustainability.  相似文献   

15.
Understanding the trade-off relationships between ecological, economic and social objectives is important in designing policies to manage or restore ecosystems. Using the northern South China Sea (NSCS) as a case study, we explore the trade-offs between conservation and socio-economic objectives in managing fisheries in tropical marine ecosystems. Using a numerical optimization routine and ecosystem modelling (Ecopath with Ecosim), the study shows that current management of the NSCS is sub-optimal both in terms of conservation and economic objectives. Therefore, improvement in both conservation status and economic benefits can be achieved by reducing fishing capacity. However, the implementation of conservation plans may be hindered by the reduced number of fisheries-related jobs and the lack of alternative livelihoods. Similar trade-offs are apparent in many tropical marine ecosystems. Thus, this paper supports claims from previous studies that solving the alternative livelihood problems appears to be a priority for improving management and conservation in these ecosystems. A buy-back scheme that is funded by fishers might be effective in reducing fishing capacity. However, public funds are required if management objectives focus strongly on conservation. This might be justified by the direct or indirect benefits to society that could be provided by well-conserved ecosystems. This study highlights the conflict between maximizing conservation and social objectives, although win-win solutions between conservation and economic objectives may be possible.  相似文献   

16.
Optimal Harvesting of an Age-Structured Schooling Fishery   总被引:1,自引:0,他引:1  
Biologists have criticized traditional biomass models in fishery economics for being oversimplified. Biological stock assessment models are more sophisticated with regard to biological content, but rarely account for economic objectives. This study includes a full age-structured population model for studying schooling fisheries and extends the delayed difference approach used in earlier studies. We take the total harvest as the choice variable, resulting in a simple analytical structure. The model produces optimal steady states that may be higher or lower compared to the delayed-difference formulation. The model is applied to the Baltic sprat fishery. Both ecological and harvesting cost data support specifying Baltic sprat as a schooling fishery. Given nonlinear harvesting costs, the optimal solution is a path toward a steady state with smooth annual harvest and population age structure. Sensitivity analysis shows that the optimal solution is highly dependent on the population level of the sprat’s main predator Baltic cod. A linear cost function and an interest rate below 9 % imply pulse fishing instead of smooth continuous harvesting. Given nonlinear harvesting cost, the optimal steady state yield is rather insensitive to changes in the interest rate. However, under a high cod scenario, interest rates of 10 % or higher implies that no optimal steady state exists.  相似文献   

17.
In an important contribution in Ecological Economics, van de Bergh (2010) correctly concludes that sustainability does not imply zero externalities. However, he continues with the Delphic statement "(Delphic statements were uttered by the renowned oracle of ancient Greece at Delphi. They were phrased in such a way as to be self-fulfilling because alternative interpretations covered every possibility.)" "Without externalities the problem of sustainability vanishes". If this statement refers to an impossible economic process that produces no externalities then he is right. However, it might be interpreted as stating that whenever environmental policy internalizes environmental externalities then sustainability will be ensured. In this note, I assert that in the real world where externalities prevail, their internalization or neutralization in the traditional way cannot lead to sustainability. Only if internalization takes a very specific form that results in the inviolable preservation of environmental rights of future generations in pure biological terms can sustainability be ensured. After revised the original commentary I resubmit it. The issues raised by the editor have been carefully considered.  相似文献   

18.
This paper develops a formal analysis of the recovery process for a fishery, from crisis situations to desired levels of sustainable exploitation, using the theoretical framework of viable control. We define sustainability as a combination of biological, economic and social constraints which need to be met for a viable fishery to exist. Biological constraints are based on the definition of a minimum resource stock to be preserved. Economic constraints relate to the existence of a guaranteed profit per vessel. Social constraints refer to the maintenance of a minimum size of the fleet, and to the maximum speed at which fleet adjustment can take place. Using fleet size adjustment and fishing effort per vessel as control variables, we first identify the states of this bioeconomic system for which sustainable exploitation is possible, i.e. for which all constraints can be dynamically met. Such favorable states are called viable states. We then examine possible transition phases, from non-viable to viable states. We characterize recovery paths with respect to the time of crisis of the trajectory, which is the number of periods during which the constraints are not respected. The approach is applied to the single stock of the bay of Biscay Nephrops fishery. The transition path identified through the viability approach is compared to the historical recovery process, and to both open-access and optimal harvesting scenarios.  相似文献   

19.
This dissertation focuses on the political economy of fisheries governance. The study develops a formal model of fisheries governance by combining the features of the common pool fishery and the political institution of lobbying; designs a laboratory fishery governance institution and conducts economic experiments to test the hypotheses derived from the formal model. Specifically, the study analyzes how fishing firms invest in efforts to influence fishery regulation and management through voluntary contribution lobbying. The study also analyses and compares contribution and effort behavior in the lobbying and the CPR using data from economic experiments. The results indicate that lobbying to change suboptimal fishery regulations was significantly below the subgame perfect equilibrium prediction and contributions to raise the cap were significantly different than contributions to lower the cap toward the social optimum. Study results show that subjects successfully lobbied to raise inefficiently low fishing quotas, but were unable to lobby to reduce inefficiently high fishing quotas. Detailed analysis of subjects’ contribution and effort behavior suggest that despite the interesting benefit-cost duality between pure public goods and CPRs, the pattern of cooperative behavior in these two social dilemma situations was different and the level of cooperation in the voluntary contribution lobbying experiment was lower than those reported in other public goods experiments. To provide external validity to these experimental findings, the study further analyzes and compares lobbying expenditures in the fishery sector with those in other natural resource industries using field data from the United States. A comparison of actual lobbying expenditures as percentage of valued added shows that lobbying effort in the U.S fishery sector is not significantly different than those in other natural resource industries such as mining and electric utility industries, but the pattern of lobbying is different. Whereas fishing firms lobby through associations or pressure groups, firms in other natural resource industries lobby unilaterally. This observation suggests that differences in industrial structure and incentives influence the pattern of lobbying and the lobbying behavior of firms across industries. The theoretical predictions derived from the formal model of fisheries governance are consistent with our experimental findings and with the field data on lobbying in the US fisheries sector. These findings suggest that heterogeneity drives rent-seeking activities in the US fisheries sector and that fishing firms attempt to circumvent political collective action problems by forming and lobbying through associations of stakeholders with relatively homogenous policy preferences. JEL Classification D22, D72, D78, H41 Advisor: Prof. Jon G. Sutinen  相似文献   

20.
Throughout its history, America has viewed its oceans as vast fishery frontiers. These frontiers are suffering depletion as large amounts of fishing power combined with significant oceanographic changes are straining the limits of sustainability. The new ocean frontier is not the promise of undeveloped resources, but rather the challenge of undeveloped sustainable governance systems. This paper discusses the institutional transformation necessary to achieve sustainable governance. The first part provides an historical overview of the American use of resources as frontiers. The second part characterizes the frontier as an extreme form of resource use, contrasting it to its opposite ideal, the commons. The third part outlines behavioral differences between the users of frontiers and commons, the pioneers and shareholders. Building on the attributes of resource management under the two ideals, the fourth part of the discussion focuses on the necessary conditions and major challenges to developing the institutional capital required for sustainable US fishery management. The institutional capital needed for sustainable fisheries governance is comprised of several pieces: (1) A perception of the fishery as an integrated ecosystem; (2) an identification of shareholders; (3) an allocation of decision making power and responsibility which vests all interests and internalizes the source of control; (4) incentive structures to promote long-term management; (5) management skills among fishery interests; (6) management processes that promote adaptability to change. The final section provides conclusions and an assessment of the progress US fishery management has made in institutional capital development. Pressures of scarcity are forcing US fisheries management to evolve away from the frontier ideal, but the development of the institutional capital necessary for sustainable fishery governance is incomplete.  相似文献   

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