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1.
Overcapacity (OC) and excess capacity (EC) are serious obstacles affecting the sound management of commercial fisheries around the world. The use of individual fishing quotas (IFQs) has been proposed as a promising management tool to cope with these challenges. However, the empirical evidence on the efficacy of this instrument is scarce. Drawing on a stochastic distance frontier analysis, we investigate the impact of the US Gulf of Mexico red snapper IFQ program on fishing capacity, capacity utilisation (CU) and OC. The paper also offers an alternative approach to compute species‐specific capacity measurements for multispecies fisheries. Our findings show that following the introduction of the IFQ program, fishing capacity decreased, primarily due to the exit of a large number of fishing vessels. CU increased marginally indicating modest decreases in EC. Conversely, we find that OC remains high. Our estimates suggest that about one‐fifth of the actual fleet could harvest the entire quota.  相似文献   

2.
The success of regulations of multispecies fisheries may depend critically on understanding output dependencies correctly. An example is purse seine fisheries that target several species over the season but are specialized in the sense that each species are targeted individually. Such fisheries are typically modeled as either independent single species fisheries or using standard multispecies functional forms characterized by jointness in inputs. We argue that production of each species is essentially independent but that jointness may be caused by competition for fixed but allocable input of vessel capacity. We develop a fixed but allocatable input model of purse seine fisheries capturing this particular type of jointness. We estimate the model for the Norwegian purse seine fishery and find that it is characterized by nonjointness, while estimations for this fishery using the standard models imply jointness.  相似文献   

3.
In this study, we analyse effort optimisation in common rights‐based joint‐stock artisanal fisheries when several objectives are pursued by the authorities and the fleets are heterogeneous. The purpose is to discuss policy options available to the authorities and their implications in terms of trade‐offs between goals. We apply a multi‐objective programming model to the sardine and anchovy artisanal fisheries in central southern Chile. The results suggest that the regulatory system generates inefficient solutions for profit and employment maximisation goals. Moreover, the fleet structure of the artisanal organisations is central for the outcomes obtained by different policy simulations. To improve effort assignment, the authorities should seek to increase flexibility in the system.  相似文献   

4.
We present the first ex post study that quantitatively analyses the effects of a licence buy‐back and enhanced quota trading on the profitability and productivity of individual vessels in a fishery. Using firm‐level data and a profit index decomposition method, we find that small and large vessels and three different trawler fleets all experienced substantial productivity gains in the year immediately following a licence buy‐back and the establishment of a quota brokerage service. The apparent ongoing benefits of the buy‐back and increased quota trading over the sample period are in stark contrast to the generally unfavourable long‐term outcomes commonly associated with vessel buy‐backs in input‐controlled fisheries.  相似文献   

5.
Annual recruitment of the New Zealand longfin eel (Anguilla dieffenbachii) has decreased by 75 per cent since significant levels of commercial fishing began in the early 1970s. This motivates application of a multiple‐cohort bioeconomic model to a New Zealand longfin eel fishery to investigate its optimal management and ascertain the suitability of existing regulatory policy. The use of historical harvest to calculate total allowable catch is asserted to be unsustainable based on recovery dynamics. In addition, individual transferable quota systems are argued to be fundamentally flawed for the protection of longfin fisheries because of high‐grading, low‐surplus production and a current lack of effective stock‐assessment procedures. Area closure and the spatial definition of harvest rights are attractive alternatives given the territoriality of longfins and high larval spillover. The importance of unfished reserves is reinforced when significant uncertainties regarding population strength, harvest intensity and growth dynamics are considered. Restriction of exploitation to older cohorts in fished areas is demonstrated to maximise economic yield.  相似文献   

6.
The Atlantic salmon has been harvested by both commercial and recreational fishers for many years on the river systems of the province of New Brunswick on Canada 's Atlantic coast. The commercial fisheries were closed and controls were placed on the recreational fisheries following the 1983 collapse of the salmon stocks. This management policy remains in effect. A preliminary analysis using a linear control model showed this to be an economically efficient harvest allocation policy on New Brunswick's Miramichi River. The analysis is extended to the more realistic nonlinear framework here to determine whether the harvest allocation decision would be significantly changed. Both fisheries are found to generate positive net economic benefits, although the recreational fishery is determined to be more valuable than the commercial fishery. Permanent closure of the commercial fishery is not indicated.  相似文献   

7.
World-wide, forest managers have long recognised the benefits of using optimisation-based modelling techniques to improve decision-making. With no such systems in operation in Irish forestry, optimisation-based economic models were developed for harvest scheduling on a forest level within the context of a hierarchical approach. These new techniques were compared to those currently employed by Coillte Teoranta (the Irish Forestry Board). The development of the optimisation models involved the evaluation of: different management options strategies, optimisation techniques, model types and constraint strategies. Evaluation of the models was carried out in Clonbrock forest (294.8 ha), a typical Irish plantation forest, owned and managed by Coillte. The application of the selected model resulted in an increase in net present value (NPV) over the 5-year planning period of 14.2% compared to the NPV produced by Coillte's current process.  相似文献   

8.
Illegal foreign fishing for sharks in Northern Australia has increased substantially over the last two decades. This has likely resulted in declines of shark species abundance, with potentially far‐reaching impacts on the ecosystem. This, in turn, could also have indirectly affected the legal prawn, shark, and other fisheries in the region through changed predation patterns and direct removal of targets. The prawn fishery in Northern Australia is currently one of Australia's most valuable fisheries. Sharks themselves are also a major target species by many Queensland and Northern Territory fishers. In this article, an ecosystem model developed in the Ecopath with Ecosim framework is used to estimate the impacts of illegal shark fishing on the remaining system, and the potential economic impacts on commercial fisheries in the region.  相似文献   

9.
渔业配额捕捞的制度构成及解析   总被引:1,自引:0,他引:1  
渔业配额捕捞制度主要由TAC设定、分配配额、交易机制、监管措施等层面构成。其中,TAC设定主要由锁定目标鱼种、求取MSY、确立TAC三个层面构成;分配配额主要由配额发放对象和分配方法两个层面构成;交易机制则由参与交易的主体和客体、交易场所以及反垄断措施等层面构成;监管环节包括渔船监测系统、观察员制度、捕捞日志等措施手段。结合发达渔业国实践经验,通过对制度各层面的剖析,希冀为我国配额捕捞的启动实施提供有益参考。’  相似文献   

10.
This paper estimates the inefficiencies associated with the regionalisation of the milk quota trade. An optimisation model is developed to estimate the economic value of quota. Quota values are aggregated to derive quota sale and purchase curves under two scenarios: first, where quotas can be traded nationally and second, where the trade of quota is regionally restricted. Quota trade is simulated and the consequent effects on supplier structure estimated. Through the derivation of sectoral cumulative cost curves it is possible to estimate the impact of regionalising quota trade on sector efficiency. The model is solved using National Farm Survey data from Ireland and the inefficiencies of regionalised quota trade in Ireland are estimated at €27 million. The paper concludes by discussing the implications of restricted quota trade, especially in the context of eventual quota removal.  相似文献   

11.
Interdependencies among land use systems resemble a complex network connected through demand–supply relationships. Disruption of this network may catalyse systemic risks affecting food, energy, water and environmental security (FEWES) worldwide. We describe the conceptual development, expansion and practical application of a stochastic version of the Global Biosphere Management Model (GLOBIOM), used to assess competition for land use between agriculture, bioenergy and forestry at regional and global scales. In the stochastic version of the model, systemic risks of various kinds are explicitly covered and can be analysed and mitigated in all their interactions. While traditional deterministic scenario analysis produces sets of scenario‐dependent outcomes, stochastic GLOBIOM explicitly derives robust outcomes that leave the systems better‐off, independently of which scenario applies. Stochastic GLOBIOM is formulated as a stochastic optimisation model that is critical for evaluating portfolios of robust interdependent decisions: ex‐ante strategic decisions (production allocation, storage capacities) and ex‐post adaptive (demand, trading, storage control) decisions. As an example, the model is applied to the question of optimal storage facilities, as buffers for production shortfalls, to meet regional and global FEWES requirements when extreme events occur. Expected shortfalls and storage capacities have a close relationship with Value‐at‐Risk (VaR) and Conditional Value‐at‐Risk (CVaR) risk measures. A Value of Stochastic Solutions is calculated to illustrate the benefits of the stochastic over the deterministic model approach.  相似文献   

12.
This paper examines the allocation problem arising from conflicting demands for marine resource use by (i) commercial fishers, (ii) recreational fishers, and (iii) conservationists. It is shown that decentralised trading of individual transferable quotas (ITQs) is capable of an efficient allocation of resource use between the first two parties. In contrast, it is found that the standard ITQ system is not capable of performing the same ideal co‐ordination between the conflicting interests of extractive users, that is, all fishers, and the non‐extractive ones, that is, conservationists. The reason is that quota trades between individual fishers and conservationists are inevitably accompanied by (positive) externalities on both other fishers and conservationists. As a result, decentralised quota trades between these parties cannot be efficient. The fundamental economic observation is that quotas for conservation and for extraction constitute two different goods. It follows that a socially optimal market allocation of these two goods requires two prices instead of the single quota price in the standard ITQ system. Thus, to achieve efficiency, the ITQ system has to be extended to incorporate both types of goods. It is shown in the paper that if fishers and conservationists can organise themselves into groups, trades of conservation quotas between the two groups can in principle lead to fully efficient allocation. An interesting implication of this modified ITQ system is that the need for a fisheries authority to set the total allowable catch (TACs) disappears.  相似文献   

13.
国内外渔业资源管理制度研究进展   总被引:1,自引:0,他引:1  
通过科学的渔业资源管理制度实现渔业资源合理开发和有效保护,是渔业管理的重要方面。渔业资源管理可分为资源限制开发和资源修复两大方面,渔业资源的限制开发具体表现为捕捞限额制度和捕捞配额制度,其理论基础为渔业权制度。渔业资源养护主要是增殖放流制度。近年来,国内外学者在渔业权、捕捞限额和配额制度、增殖放流制度等方面的研究不断深入,取得了较大进展,对我国渔业资源管理制度建设具有很好的参考和借鉴意义。  相似文献   

14.
Rock lobster fisheries are Australia's most valuable wild fisheries in terms of both value of production and value of exports. Different states harvest and export different lobster species, with most of the landings being sent to the Hong Kong market. A perception in the Australian lobster industry is that the different species are independent on the export market, such that a change in landings of one species has no impact on the price of the others. This study investigates the market integration of Australian exports to Hong Kong for the four species and different exporting states. Our results indicate all four species and producers/export states are perceived to be substitutes for one another, so that, in the long run, prices paid to operators in the industry will move together. The integrated nature of the Hong Kong export market for Australian lobster suggests that the potential impacts of alternative fisheries management and development strategies at state and species levels cannot be considered in isolation, at least from an economic perspective. In addition, impacts of external shocks affecting production in one state (e.g. climate change) can be expected to affect all Australian lobster fisheries.  相似文献   

15.
Farmland abandonment is a widespread process with mixed socio-economic and environmental consequences. Farmland abandonment in Rio de Janeiro State is mainly instigated by the sugarcane industry crisis. The sugarcane crisis in Rio de Janeiro State affected traditional livelihoods and altered the environment and economy in the Norte Fluminense region (eastern part of Rio de Janeiro State). Therefore, it is essential to understand the underlying forces and contributory causes of farmland abandonment in Rio de Janeiro. We hypothesized that since the 1970s, macroeconomic and agricultural reforms mediated by economic shocks had driven the farmland abandonment in Rio de Janeiro State. We applied an interrupted time-series analysis over sugarcane harvest areas, relating the years of policy reforms and economic shocks to the trends in sugarcane harvest areas. The results suggest that the removal of agricultural subsidies, macroeconomic reforms, and elimination of the supply quota in the sugar mills have prompted competition and favored high-input agroindustry. Meanwhile, the labor force migration to the higher-paying oil Industry exacerbated the farmland abandonment rates for the smallholders of Rio de Janeiro State. This paper offers a valuable contribution to scientists and policymakers by providing an overview of the outcomes of the policies implemented and how they contributed to shaping the socio-economic dynamics in Rio de Janeiro State.  相似文献   

16.
Since the early 1970s there has been interest in the application of optimal control theory to the management of economic systems. Specifically, optimal control theory prescribes policy strategies which optimise a quantifiable policy preference function subject to market equilibrium conditions. Problems of this kind have been identified among agricultural markets and this paper aims to illustrate the application of optimal control theory to the British potato market. The paper takes evidence from policy makers to derive target values for the producer price, imports, and the changes in the quota area from year to year. The constraints on optimisation are specified in terms of a partial equilibrium econometric model which specifies, demand, supply and trade relationships. The policy preference function is specified as a quadratic and a ‘revealed preference approach’ is employed to estimate the parameters which penalise market equilibria which over or under-shoot policy targets. The resulting optimal control problem is minimised by a dynamic programming routine. The results suggest that policy makers may benefit from taking dynamic effects directly into account when formulating policy strategies.  相似文献   

17.
浅析中国渔业保险模式的选择   总被引:8,自引:0,他引:8  
随着中国渔业的快速发展,对渔业风险保障体系的构建提出了迫切要求,而渔业保险是市场经济条件下保障渔业生产经营活动稳定性的有效途径。本文从中国渔业保险的经营现状着手,指出中国目前还没有适合自身的渔业保险模式,在分析对比世界上存在着的六种渔业保险模式和参考中国保监会提出的五种农业保险模式的基础上,首次提出适合中国国情的新模式,即渔业相互保险公司经营渔业原保险,商业保险公司经营渔业再保险的渔业保险经营模式,并对该模式的构建进行了初步探索。  相似文献   

18.
研究目的:基于上海市建设用地减量化的政策背景,分析上海市土地指标交易现状与存在的问题,探讨如何建立土地指标市场化交易机制,为上海市土地利用制度改革提供经验借鉴。研究方法:文献研究法、比较分析法和实地调查法。研究结果:上海市土地指标交易存在交易半径较狭小、市场化程度较低、定价机制不合理、收益分配不完善等一系列问题,应研究市场竞争与政府调控相结合的指标交易机制。研究结论:针对经济快速发展与土地指标短缺的现实矛盾,上海市政府应从机制构建与配套措施两方面进行土地指标市场化交易体系建设,以推动上海市土地市场的发展。  相似文献   

19.
The economic efficiencies of the Danish, Icelandic, and Norwegian cod fisheries are examined. For this purpose, nonlinear aggregate models of these fisheries are constructed. Comparing the calculated optimal harvest and biomass quantities with the actual fisheries provides a measure of the degree of efficiency in these fisheries. The comparisons confirm that the cod harvesting policies of these countries have been hugely inefficient in the past. It appears that inefficiency has been increasing over the last three to four decades, even after TAC regulations replaced open access, indicating that the management policies adopted by all three countries have failed to cure overfishing.  相似文献   

20.
An important challenge in managing renewable resources is to understand why owners and managers sometimes make decisions that deplete resources and future earnings, such as when graziers allow pastures and land condition to be degraded. In this paper, we test two potential reasons for unsustainable management practices, myopia and salience, with each explaining why resource managers may exhibit impatience in harvest decisions. Myopia is associated with decision makers placing lower weight on future outcomes than would be implied by their pure time preference. Salience is associated with overweighting of consumption ‘now’, implying inconsistency in time preferences. To test for these effects on renewable resource management, an incentivised, dynamic field experiment was carried out with rangeland grazing enterprise owners in north‐eastern Australia that related management choices with uncertain rainfall events to both profits and land condition over time. Results demonstrate that respondents exhibiting myopia/salience in their choices tended to achieve lower cumulative scores in the experiment, as well as lower land conditions on their properties as measured with remote sensing data. Our results explain why there may be persistent optimisation failures by resource owners that reduce both profits and environmental outcomes.  相似文献   

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