Storage and Viability of a Fishery with Resource and Market Dephased Seasonalities

In this study we analyse the role of the storageregulation in a fishery's production process when theresource exploited and the market to which theproduction is exported are characterized by seasonaldephased oscillations. For this purpose we built up adynamic model drawn from the French Guyana shrimpfishery example. The underlying objective of the modelis not the maximisation of a given criterion (as wouldbe in the optimal control approach), but merely themaintenance of the fishery's economical viability. Thefundamental principle is here to try to preserve asmany as possible viable control options. Theconditions to achieve and maintain this viability arecaptured in a certain number of constraints. Theanalysis points out periods and situations within theseason where the fishermen must anticipate theevolution of their storage to avoid violating thoseviability constraints. The study also indicates howthe fishery's viability can be ensured even if theexploitation costs exceed the commercial value of thelandings for a finite part of the year. However, whenthe resource's and/or market's oscillations are toolarge, the fishery may be not viable any longer and itappears that the crisis can not be removed byinvesting in larger storage capacities.     

Asymmetric volatility of stock returns during the Asian crisis: Evidence from Indonesia

This paper investigates the conditional volatility in stock returns in Indonesia over the period covered by the Asian crisis. Rolling regression parameter estimates from three asymmetric volatility models suggested that all parameters, including those capturing asymmetric response, were time-varying. The precise pattern of adjustment was sensitive to model selection. Nevertheless, increases in asymmetric response patterns appear to coincide with the very large exchange rate devaluations in the rupiah over this period and were followed by more general symmetric short-term volatility in the post crisis period. Estimates from a smooth transition volatility model indicated both sign and size asymmetries during the crisis period.     

Sustainability of an economy with an exhaustible resource: A viable control approach

We examine the conditions for the sustainability of a production–consumption system based on the use of an exhaustible natural resource. Instead of studying the environmental and economic interactions in terms of optimal control, we focus on the viability of the system, defined by a set of constraints combining guaranteed consumption and a stock of resources to be preserved at all times, which refers to a Rawlsian intergenerational equity perspective. Using the mathematical concept of viability kernel, which makes it possible to deal with the consistency between constraints and controlled dynamics, we exhibit the sustainable technological configurations and, whenever possible, the policy options and environmental-economic states required to obtain a perennial system. We point out the flexibility of the sustainable “extraction–consumption” choices and we show how they are neither reduced to constant consumption paths nor to Hartwick’s rule. Numerical simulations illustrate the general results.     

International Management Strategies for a Straddling Fish Stock: A Bio-Economic Simulation Model of the Norwegian Spring-Spawning Herring Fishery

In this paper, a three-country dynamic bio-economic simulation model is presented for the spring-spawning herring fishery. The international spring-spawning herring fishery, based on potentially one of the most valuable fish stocks in the world, is currently recovering from a severe depletion of the stock and subsequent harvesting moratorium. Management of the herring fishery is complicated by its multi-nation exploitation, due to the highly migratory behaviour of the species moving between several coastal state zones (exclusive economic zones, EEZs) and the high seas (Ocean Loop). Based on extensive work invested on analysing both the biology of the herring stock and the fisheries economics around its exploitation we study here the profiles of different multi-agent management schemes, simulating catch levels, stock size and profit potentials of alternative management strategies. The stock dynamics are described by a linear discrete-time age-structured population model and the economics are presented by a rent maximising model with constant price of herring catch and different costs of harvesting and efficiency levels for the different national fleets. The simulations, carried out over several decades, show that the benefits of international co-operation far exceed the returns of a competitive open access fishery.JEL Classifications: C7, C15, Q22     

Creating Asset Accounts For A Commercial Fishery Out Of Equilibrium: A Case Study Of The Atlantic Sea Scallop Fishery

This paper demonstrates a methodology for constructing asset accounts for a commercial fishery in which the stock, harvest, and effort level are out of sustainable equilibrium. The paper adopts the framework used by the U.S. Department of Commerce Bureau of Economic Analysis in its preliminary 1993 Integrated Economic and Environmental Accounts and follows methodologies recommended by the National Research Council committee constituted to review those efforts. The accounts were constructed for the period 1985 to 1995 for the Atlantic sea scallop fishery, a significant commercial fishery, using information obtained with the cooperation of the National Marine Fisheries Service from existing databases constructed for management purposes. No significant additional data collection was required for the purpose of this study. Differences between the net rent and user cost values of the stocks over this period indicate the inefficient exploitation of immature scallop populations.     

北极渔业治理的研究综述

气候变暖下的北极渔业逐渐引起国际关注,而技术进步使人类进入北极成为可能,发展北极渔业成为缓解全球海洋渔业资源危机的可行方式。北极拥有丰富的渔业资源,但北极的生态环境极为脆弱,如何有序发展北极渔业、实现北极渔业的有效治理是当前国际社会议论的热点。运用文献综述法,对北极渔业资源相关研究进行归纳,从现有法律制度、管理组织、影响北极渔业治理的主要因素方面总结出北极的渔业治理与一般海洋渔业治理的不同之处,并对未来北极可行的渔业治理模式进行展望。     

Institutional constraints,double imbalances and policy option—global financial crisis and China’s fiscal policy

With the enormous development of China’s economy, we re-implement the proactive fiscal policy not only to response to the global financial crisis, but also to take advantage of the opportunity to resolve the institutional constraints, transform China’s economic growth pattern, keep stability and promote the sustainable growth of the economy. So the goal of fiscal policy should weigh easing the economic crisis against long-term stability and the development of economy. The past experiences of fiscal policy practices in China indicate that the traditional simple counter-cyclical fiscal policy may be able to pull the economy out of recession, but it has little effect on automatic recovery of the economy. Therefore, the fiscal policies need to hang on the entire reform process and the whole economic structure adjustment. This paper firstly reveals the root of “double imbalances” and institutional constraints, then analyzes the paradox between such constraints, and discusses the space of positive fiscal policy.     

Investing in natural capital as management strategy in fisheries: The case of the Baltic Sea cod fishery

Many of today's fish stocks are officially managed following the precautionary approach. Yet, different political objectives and uncertainties among fishermen about their economic future make its implementation difficult. Over 75% of all commercially valuable stocks are exploited, overused, or collapsed and in a state of recovery [FAO, 2004. The state of the world fisheries and aquaculture. FAO, Rome. Managing fish stocks with an ecosystem-based approach is likely to stop the divestment of natural capital by combining sustainable use strategies with the preservation of marine ecosystems. Using the example of the Baltic Sea cod fishery, we show that a recovery program is economically and ecologically viable and reduces negative externalities. While policy makers must assist fishermen during the early years of the program, fishermen will experience greater landings and profits in subsequent years.     

Cooperative and Non-Cooperative Exploitation of the Arcto-Norwegian Cod Stock

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.     

Keeping the big fish: Economic and ecological tradeoffs in size-based fisheries management

We explore several issues raised by a size dependent regulation of a fishery in a situation where it is important for conservation purposes to keep highly reproductive big fish and where the fish prices depend on their body size. Firstly, we represent in a common modeling frame, the interplay between the biological characteristics of the exploited species (growth, reproduction) and the price/size relationship. Secondly, we explore the benefits of conservation measures based on a maximum body size for the fish caught instead of a minimum body size. As a result of computations, it appears that one should ask whether a management based on a maximum body size is not both possible to implement and equally protective of the stock, even when the price function depends on the size of fish.     

Measuring potential profits in a bioeconomic model of the mixed demersal fishery in the North Sea

This paper measures for potential profit in the North Sea mixed demersal fishery for cod, haddock and whiting. Dynamic bioeconomic models for three UK fisheries are developed, incorporating both population dynamics and economic structure. Actual profit in 2006, for the three UK fleets included in the analysis, is estimated at ??10.3?million. If the TAC remains unchanged but vessels are allowed to harvest at near efficient levels with fleet size reduced accordingly, potential profit is measured at ??34.5?million. If demersal stocks are allowed to recover to near optimal levels potential UK profit exceeds ??185?million. This indicates substantial profit dissipation due to overcapacity and stock depletion in the fishery. The results of the paper should be of policy interest and will add to the empirical literature on resource profits in mixed demersal fisheries.     

Valuation and Management of Fishing Resources Under Price Uncertainty

The traditional expected-net-present-value methods cannot properly capture the management flexibility and strategic value aspects of a fishery, and may understate its value. Instead, this paper develops a Real Options model to conceptualize and evaluate fishery exploitation flexibility. Specifically, general models to value the opportunity to either exploit or invest in a fishery are presented. They suffice to determine not only these values, but also the optimal policy for opening, closing, delaying and setting its harvest rate. The sustainable case in which the harvest rate equals the natural net growth function is also considered. Concerning the exploitation decision, it is found that, as could be expected, the higher the resource price the higher the value of this opportunity in both models (general and sustainable). However, the resource stock affects both models differently. As to the investment opportunity, its value is always lower than the exploitation opportunity because of investment costs. Finally, numerical simulations are run in order to illustrate the nature of the solution. Sensitivity analysis concerning the influence of the tax rate, convenience yield, risk-free interest rate and price volatility on the value of the fishery is also reported. Earlier versions of this paper have benefited from conference participants at the Young Economists Conference 2000 (Oxford University), Tenth Biennial Conference of the International Institute of Fisheries Economics and Trade (Oregon State University), XXV Simposio de Análisis Económico (Universidad Autónoma de Barcelona, Spain) and Seminar at the Dpt. Fundamentos del Análisis Económico (Universidad del País Vasco, Spain). We especially thank Prof. Ian Bateman and two anonymous referees whose insightful comments have enabled us to eliminate several errors and to improve the presentation. Murillas gratefully acknowledges doctoral fellowship from Ministerio de Educación y Ciencia (AP96), and financial support from the Xunta de Galicia (PGIDT01PXI30004PR) and from the Ministerio de Ciencia y Teconología (SEC 2001-3700). The usual disclaimer applies.     

Boundary conditions for the sustainable use of major fish stocks in the Baltic Sea

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.     

Economics of biodiversity and sustainable fisheries management

Marine ecosystems are complex, and many marine species are ecologically interdependent. As a result, losing a species could produce a cascading effect on other species. Fishery scientists advocate an ecosystem-based approach to fishery management to meet long-term sustainable goals. This paper models the complex interrelationships among species and the relationship between biomass growth and phenotypic diversity. We found that the equilibrium stock and catch/yield levels are overestimated when the diversity is not accounted for. Consequently, if species are diverse, fishery policy based on a single fishery management could overestimate catch potentials and potentially results in biological overfishing and stock collapse.     

Open access harvesting of the Northeast Atlantic minke whale

The purpose of this paper is to analyze open access exploitation of the Northeast Atlantic minke whale. In particular the question whether open access could lead to stock extinction is addressed. A bioeconomic model of the open access fishery is developed and estimated for data from Norwegian whaling. Numerical analysis shows that open access was not likely to have lead to stock extinction for the minke whale.     

流动性约束与货币政策的资产价格效应

本文在新凯恩斯主义分析框架下,基于一个动态随机模型探讨了代理人消费流动性约束下的货币政策的资产价格效应,得到下列结论：资产价格波动通过财富效应影响代理人的消费。以利率为操作目标的最优货币政策应对股价、房价等资产价格波动做出反应,而其反应强度依赖于受流动性约束的代理人所占的比重。由于资产价格波动导致了流动性约束的时变性,最优利率规则对股价、房价等资产价格波动的最优权重也具有时变性。本文的实证分析表明,我国央行对房价和股价波动的利率调整具有时变性,以及此次金融危机爆发期间显现的这种时变性特征,与本文理论分析结果相吻合。     

贸易自由化、产出结构与产出水平

外资流入劳动密集型产业虽然直接地避免了转轨初期产业结构之存量调整,但这还不是问题的全部,更重要的是,外资流入提高了均衡状态下资本密集型产业的比重,这又起到了避免转轨初期产业结构之存量调整的作用。对于转轨国家来说,资本流入具有增量调整之功效,而产品国际间流动则加剧转轨初期产业结构之存量调整。改革开放以来中国经济的持续高速增长可能得益于大规模的资本流入和产品市场的逐步开放的策略。     

Do good governance provisions shelter investors from contagion?Evidence from the Russian crisis1

This paper studies how the Russian crisis of 1998 affected listed firms in transition economies. The data cover 394 companies that were listed before the Russian crisis, and include financial, industry, ownership and stock market information. Results show that in the short term (within one month of the crisis) good governance did not shelter investors from contagion. On the contrary, stock returns during the crisis period were lower for the largest and most liquid stocks and markets in the region irrespective of their direct exposure to Russia. The paper also documents that in the longer term (one year after the crisis) recovery was faster in firms without direct trade exposure to Russia, as well as in firms with better firm‐level governance as proxied by the presence of a foreign blockholder. The paper presents evidence that both firm‐ and country‐level characteristics are important in overcoming the effects of a crisis. Firm‐specific characteristics, however, play a bigger role for companies operating in countries with weaker corporate governance.     

Fishing in a Shallow Lake: Exploring a Classic Fishery Model in a Habitat with Shallow Lake Dynamics

Renewable resources such as fish exist within habitats. Harvesting activities may directly impact the habitat, beyond the influence caused by changing the balance between species. When harvesting activities impact stock size and habitat health in different ways, both states must be explicitly considered. A classic fisheries model is embedded in a habitat that exhibits shallow lake dynamics, where carrying capacity depends on habitat health and fishing effort damages the habitat. Hysteresis in the habitat dynamics can manifest itself as multiple steady states for both the dynamic and open access solutions. Numerical explorations of the model suggest that a new fishery in such a setting should often be managed to protect the health of the habitat, while it may not be optimal to restore a fishery in an already degraded habitat. Conventional policy tools applied in their classic form are unlikely to be effective.     

双重二元转型与结构调整:模型、命题与中国的经验结果

通过结构调整实现经济增长方式的转型是新时期中国经济实现可持续增长的关键。按照科学发展观的思想,转型成功的核心在于科学地认识我国经济结构演进的机制,而这必须基于对我国经济环境约束条件的清晰认识,以及以此为前提的科学逻辑分析。据此,文章从中国城乡和地区的经济双重二元性现实出发,通过构造一个跨部门和地区的一般均衡模型,对中国结构调整的市场实现机制进行了全面考察。文章认为,中国的结构调整可以通过城乡和地区在要素与产品等方面的结构性互动实现,而其具体的实现机制是地区与城乡非均衡所带来的套利机会,政府的作用在于在尊重这种规律的基础上,着力于解决市场失灵问题。