SHARING THE BENEFITS OF COOPERATION IN HIGH SEAS FISHERIES: A CHARACTERISTIC FUNCTION GAME APPROACH

In the current paper we examine a game-theoretic setting in which three countries have established a regional organization for the conservation and management of straddling and highly migratory fish stocks. A characteristic function game approach is applied to describe the sharing of the surplus benefits from cooperation. We demonstrate that the nucleolus and the Shapley value give more of the benefits to the coalition with substantial bargaining power than does the Nash bargaining scheme. We also compare the results that are obtained by using the nucleolus and the Shapley value as solution concepts. The outcomes from these solution concepts depend on the relative efficiency of the most efficient coalition. Furthermore, the question of fair sharing of the benefits is considered in the context of straddling stocks.     

OPTIMAL RECOVERY OF A SHARED RESOURCE STOCK: A DIFFERENTIAL GAME MODEL WITH EFFICIENT MEMORY EQUILIBRIA

We consider an optimal two-country management of depleted transboundary renewable resources. The management problem is modelled as a differential game, in which memory strategies are used. The countries negotiate an agreement among Pareto efficient harvesting programs. They monitor the evolution of the agreement, and they memorize deviations from the agreement in the past. If the agreement is observed by the countries, they continue cooperation. If one of the countries breaches the contract, then both countries continue in a noncooperative management mode for the rest of the game. This noncooperative option is called a threat policy. The credibility of the threats is guaranteed by their equilibrium property. Transfer or side payments are studied as a particular cooperative management program. Transfer payments allow one country to buy out the other from the fishery for the purpose of eliminating the inefficiency caused by the joint access to the resources. It is shown that efficient equilibria can be reached in a class of resource management games, which allow the use of memory strategies. In particular, continuous time transfer payments (e.g., a share of the harvest) should be used instead of a once-and-for-all transfer payment.     

A dynamic equivalence principle for systematic longevity risk management

This paper addresses systematic longevity risk in long-term insurance business. We analyze the consequences of working under unknown survival probabilities on the efficiency of the Law of Large Numbers and point out the need for appropriate and feasible risk management techniques. We propose a setting for risk sharing schemes between the insurer and policyholders via a dynamic equivalence principle. We focus on a pure endowment contract and derive conditions for a viable risk sharing scheme which enhances the solvency situation of the insurer while being more favorably priced for the policyholders.     

Controlling the bullwhip effect in a supply chain system with constrained information flows

The bullwhip effect problem is one of the most important issues in supply chain management. Limited information sharing increases the difficulty of reducing the bullwhip effect and leads to inefficient supply chain management. The purpose of this paper is to explore new ways to reduce the bullwhip effect in supply chain systems that face uncertainties with respect to information sharing. We first present a supply chain state transition model, based on which we explore the endogenous mechanism of bullwhip effect, especially those related to impacts from limited information sharing. Then we propose a novel inventory control method and study the corresponding control optimization problem, with the aim of reducing inventory volatility in supply chains. Both quantitative analysis and simulation study are conducted. Simulation results show the effectiveness and flexibility of our proposed method in reducing bullwhip effect and in improving supply chain performance, even under conditions of limited information sharing.     

The impact of information sharing in a two-level supply chain with multiple retailers

Information sharing is an important component of cooperation in supply chain management. This paper presents a study to evaluate the impact of information sharing on inventory and expected cost in a two-level supply chain with multiple retailers. Three levels of information sharing are given and the optimal inventory policy under each level is derived. We show that both the inventory level and expected cost of the manufacturer decrease with an increase in the level of information sharing.     

物流末端配送资源共享中政府作用演化博弈分析

资源共享是解决物流末端配送问题的有效途径,在企业各自为政无法进行配送资源共享的情况下,政府如何发挥作用才能激发各企业进行资源共享.构建物流企业与第三方服务平台关于共享物流配送资源的演化博弈模型,考察双方在物流配送末端的资源共享行为及其影响因素,分析政府在促进末端配送资源共享中的决策机理.得出政府不参与管理时,双方超额收益都高于所投入的额外成本才能促进资源共享;政府参与管理时,在双方资源共享成本接受范围内,政府的政策补贴行为能促进资源共享的发展.从机制设计角度分析未来政府参与管理对物流资源共享的促进作用,进一步提出相应的措施建议,从而为政府的机制设计提供一些思路.     

A fair and time‐consistent sharing of the joint exploitation payoff of a fishery

We consider the problem of efficiently managing a fishery where pollution externalities are present. The open‐access bionomic model is analyzed in an ‐player differential game framework with two‐state variables, that is, the fish stock and the pollution stock. We characterize the noncooperative feedback‐Nash equilibrium and cooperative solution, and define an egalitarian sharing rule to allocate the joint welfare maximizing payoff over an infinite time horizon, and show that this rule is time consistent. Recommendations for Resource Managers

• ● Cooperation in management of a fishery where pollution externalities are present yields a higher payoff over time as compared to the noncooperative behavior.
• ● The dividend of cooperation can be allocated among the fisherpersons according to an egalitarian sharing rule.
• ● This allocation is time‐consistent, that is, no player will be tempted to deviate from cooperation as time goes by, and the initial agreement is sustainable.

     

COMPARING PROACTIVE AND REACTIVE MANAGEMENT: MANAGING A TRANSBOUNDARY FISH STOCK UNDER CHANGING ENVIRONMENT

Environmental change in general, and climate change in particular, can lead to changes in distribution of fish stocks. When such changes involve transboundary fish stocks, the countries sharing the stock need to reconsider their harvesting policies. We investigate the effects of changing stock distribution on the optimal fishing policies in a two players’ noncooperative game. We compare reactive management, under which the manager ignores future distributional shifts (knowingly or unknowingly), with proactive management where the manager considers such shifts in his decisions. A dynamic programming model is developed to identify closed‐loop Nash strategies. We show that the role of two players is symmetric under reactive management but asymmetric under proactive management where managers anticipate future changes in stock ownership. The player losing the stock tends to harvest more aggressively compared to the player gaining the stock who acts more conservatively. Strategic interactions show tendency for complementary actions that can change abruptly during the ownership transition. The differences between management regimes vary from quantitative to qualitative; differences are minimal for stocks with little or no schooling, whereas highly schooling stocks may avoid collapse only under proactive management.     

A COALITION APPROACH TO THE MANAGEMENT OF HIGH SEAS FISHERIES IN THE PRESENCE OF EXTERNALITIES

ABSTRACT. The current paper extends the coalition approach of the management of high seas fisheries to the presence of externalities. The coalition approach is set within the framework of a two‐stage game in which the payoffs depend on the entire coalition structure and are determined through a partition function. The relationship between the presence of externalities and the stability of the coalition structures is explored. The equilibrium coalition structures of the game are also examined. The application of the game to the Northern Atlantic bluefin tuna shows a typical picture of the high seas fisheries: the simultaneous presence of strong externalities in the coalition structures and the absence of stability of the grand coalition. A fundamental conclusion of this paper is that, generally, in order to guarantee the stability of the cooperative agreements it is not sufficient to implement a fair sharing rule for the distribution of the returns from cooperation. Stability requires a legal regime preventing the players that engage in noncooperative behavior from having access to the resource.     

A model for glioma growth

Glioblastoma Multiforme (GBM) is the most invasive form of primary brain tumor. We propose a mathematical model that describes such tumor growth and allows us to describe two different mechanisms of cell invasion: diffusion (random motion) and chemotaxis (directed motion along the gradient of the chemoattractant concentration). The results are in a quantitative agreement with recent in vitro experiments. It was observed in experiments that the outer invasive zone grows faster than the inner proliferative region. We argue that this feature indicates transient behavior, and that the growth velocities tend to the same constant value for larger times. A longer‐time experiment is needed to verify this hypothesis and to choose between the two basic mechanisms for tumor growth. © 2005 Wiley Periodicals, Inc. Complexity 11: 53–57, 2005     

RESTRICTED COALITIONS IN THE MANAGEMENT OF REGIONAL FISHERIES ORGANIZATIONS

ABSTRACT. In this paper, we examine a game theoretic setting in which four countries have established a regional organization for the conservation and management of straddling and highly migratory fish stocks as recommended by the United Nations Agreement. These countries consist of two coastal states and two distant water fishing nations (DWFNs). A characteristic function game approach is applied to describe the sharing of the surplus benefits from cooperation. We are specifically interested in the effect of possible coalition restrictions on these shares. According to our results the distant water fishing nations, by individually refusing to join with the coastal states, can considerably improve their negotiation position if their harvesting costs are relatively high and similar. The results show that the DWFNs may have economic reasons for negotiating as a group against coastal states. However, if the coastal states are clearly more efficient than the DWFNs then coalition restrictions may be prevented by coastal states.     

资源共享方式若干问题的研讨

社会公用服务系统和工程技术系统，存在共同的资源共享问题。本文通过典例就资源共享方式的若干问题加以探究：讨论广义的多用户系统中人工资源共享方式的分类；阐述常用的共享方式的特点、优缺点；分析系统时间性能及其改进与共享方式的关系等。文章还提出在系统工程范畴里，应对社会公用服务和工程技术两类系统的资源共享方式予以综合研究，并相互借鉴和移植。     

高管薪酬监督博弈与独立董事有效性研究

研究聚焦董事会内部沟通网络,基于独立董事信息共享机制探讨对高管薪酬的监督效果。研究发现,独立董事相互之间通过共享信息来增强对高管自利行为的抑制能力,有效降低了高管薪酬。同时,管理者权力对独立董事信息共享机制的监督效力起到调节作用,具体表现为随着管理者权力的增强,独立董事信息共享对于高管薪酬的约束作用被弱化,这一结果说明独立董事信息共享机制的监督有效性受到管理者权力的限制。研究构建了独立董事信息共享指标,并基于董事会监督博弈过程分析信息共享对高管自利行为的约束过程,最后运用A股上市公司数据加以验证。研究拓展了对独立董事监督机制的认识,为打开董事会“黑箱”、提升董事会绩效提供新视角,促进公司治理机制由静态结构研究向动态过程研究转化。     

均值-方差期望效用函数下的风险共担

借助Samuelson提出的风险汇合(Risk Adding)与风险分担(Risk Pooling)的概念,讨论了风险共担(Risk Sharing)机制产生的原理.在均值-方差效用函数下,给出了帕累托有效风险共担原则的具体形式,以及风险共担群体接纳新的个体,从而形成更大风险共担群体的条件.在此基础上,证明在均值-方差期望效用函数下,当考虑风险共担群体的形成条件以后,帕累托有效的风险共担原则等价于条件期望风险分配函数.从而在这一特殊效用函数下,建立了风险共担与风险分配函数之间的等价关系.     

云制造环境下企业制造资源共享的演化博弈分析

云制造服务平台为在不同时空上获取制造资源提供了一个良好的工作环境,它实现了产品全生命周期的协同制造、管理和创新。在明确云制造环境下企业制造资源共享模式的基础上,构建了考虑两方行为的制造资源共享的演化博弈模型,分别在博弈群体处于均匀混合和非均匀混合两种状态下,找出了模型的均衡点并对其稳定性进行分析。引入系统动力学的方法,建立制造资源共享的演化博弈SD仿真模型,对比分析不同参数变化对演化结果的影响。研究结果表明,企业群体初始共享比例、升级设备成本、信息化改善收益和技术流失风险对博弈双方的策略演化结果具有显著的影响,促进企业联盟中的信息互通与资源共享,须从上述方面着手管理并持续改进。     

Nonlinearity management in optics

We study nonlinearity management in optics by investigating the propagation of localized pulses and plane waves in a layered, cubically nonlinear (Kerr) medium that consists of alternating layers of glass and air. We show that such nonlinearity management delays the blow-up/collapse of pulses and leads to a band structure of modulationally unstable regions for plane waves. We find excellent agreement between experiments, numerical simulations, and theory. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Channel coordination through a revenue sharing contract in a two-period newsboy problem

This paper studies channel coordination through revenue sharing contract between a single retailer and a single wholesaler in a two-period newsboy problem. Two models are discussed, a single-buying-opportunity model and a two-buying-opportunity model. We discuss how the revenue sharing ratio and the wholesale prices are to be determined in order to achieve channel coordination and a win–win outcome. We find that the wholesale prices are set to be lower than the retail prices and the optimal revenue sharing ratio is linearly increasing in the wholesale prices. The proposed revenue sharing contract has more flexibility than price protection, in that the optimal revenue sharing ratio can be settled reasonably through negotiation between the retailer and wholesaler.     

FEATURES OF BIOECONOMICS MODELS FOR THE OPTIMAL MANAGEMENT OF A FISHERY EXPLOITED BY TWO DIFFERENT FLEETS

ABSTRACT. After the extension of the Exclusive Economic Zone, in 1977, to 200 miles, most fish stocks came under jurisdiction of the adjacent coastal states. This development opened prospects of effective management of the open sea fisheries. Coastal states have the right to plan out the operation of so-called by Clarke and Munro “distant water fishing nations” from their Exclusive Economic Zone. Under some arrangements, a foreign fleet is allowed to harvest the resource in the Exclusive Economic Zone area. Clarke and Munro, in [1987] and [1991], focus on the issue of optimum terms and conditions of access and, in doing so, built a multiobjective model. The main goal of the present work is the development of a more general model including more variables and parameters related to the presence of a domestic fleet as well as a distant water fishing nation. The main difficulty resides in sharing the harvesting between the two fleets. The study responds to the realistic problemof coastal states who own enough resource stocks to allow harvesting by several kinds of fleets. Two optimal scenarios are developed, in each of them a solution is given.     

CLIMATE CHANGE AND COOPERATION IN TRANSBOUNDARY WATER SHARING: AN APPLICATION OF STOCHASTIC STACKELBERG DIFFERENTIAL GAMES IN VOLTA RIVER BASIN

Abstract As multiple countries share a river, the likelihood of conflicts over distributing water resources increases, particularly under the effects of climate change. In this paper, we demonstrate how countries can cooperate in sustainable transboundary water sharing under such conditions. We examine the case of water distribution in the Volta Basin of West Africa between the upstream country, Burkina Faso, and the downstream country, Ghana. The latter faces an additional tradeoff between the production of hydropower in the south, close to the outlet of the basin, and agricultural water use in the reservoir’s catchment area in the north. In the framework of a stochastic Stackelberg differential game, we show how sustainable water‐sharing agreements can be achieved by linking transboundary flows to hydropower exports. Our results indicate that, through cooperation, Ghana will have an opportunity to increase its water abstraction for agriculture, which has remained largely restricted. We also find that the equilibrium strategies for the long‐run distribution are stable even with increasing variances of water flow.     

Platform exploitation in the sharing economy

We model a revenue sharing contract between a sharing economy platform and a freelance service provider, where the latter hides revenue from the former by canceling some assignments and performing them for cash (“platform exploitation”). The platform counters this via costly, imperfect audits with endogenous success probability, and a variable payment. We show that at equilibrium, all agent types except the highest, indulge in revenue falsification. This problem is exacerbated by the principal's ability to extract restitution from the agent.