Self-Induced Coalition Formation between Jurisdictions and Costs Allocation Rules for Development of Infrastructure

社会对水资源开发的需求正在发生变化，有必要将水的环境用途与防洪、灌溉或市政/工业用水等传统用途结合起来，作为多用途水库开发项目的目的。对多目标油藏开发成本分摊进行了实际应用研究。基于博弈论的理论研究也积累了一定的成果。然而，涉及环境利用的多用途水库开发具有一些不同的特点，如（1）没有自身水库容量的用户参与，（2）联盟的外部性，（3）成本和收益分配（净收益分配）的必要性，（4）用户自身利益的自我揭示导致的无效率，以及（5）多个备选方案存在时的成本分配。这些问题在以往的多功能油藏开发中是没有想到的。本文应用博弈论的方法，建立了多功能水库开发成本分摊问题的数学模型，并提出了改进传统的多功能水库开发成本分摊方法的建议。首先，分析了无库容用户油藏开发费用函数的特点，并对常规费用分摊方法的适用性进行了评价。第二，对成本分摊方法进行了扩展，使其能够反映联盟的外部性。第三，探讨了基于自我揭示的水库更新净效益分配机制下的效率问题。最后，针对用户偏好信息不完全和两极分化的情况，提出了一种协调机制，并将该机制应用于水电水库更新冲突中。

Societal demand for water resources development is changing, and it is becoming necessary to incorporate environmental use of water as the purpose of multi-purpose reservoir development project, together with conventional uses such as flood control, irrigation, or municipal/industrial water. Cost allocation for multi-pupose reservoir development has been examined for practical use. The Results of theoretical research based on game theory has been also accumulated. However, multi-purpose reservoir development involving environmental use has some different characteristics such as(1)participation of users without its own reservoir capacib, (2)externality of coalition, (3)necessity of cost and benefit allocation(net benefit allocation), (4)inefficiency caused by self revelation on users' own benefits, and (5)cost allocation in case plural alternatives exist. These problems were not supposed in the past multi-purpose reservoir development. In this study, cost allocation problem is formulated by using game theory, and the proposal to improve conventional cost allocation method for multi-purpose reservoir development incooporating environmental use. First, characteristics of cost function in reservoir development including users without its own reservoir capacity is shown, and the applicability of conventional cost allccation method is evaluated. Second, cost allocation method is extended to reflect externality of coalition. Third, eiffciency under net benefit allocation mechanism based on self revelation in reservoir renewal is discussed. Finany, coordination mechanism is proposed for the case where the information on users' preferences is incomplete and polarized, and the mechanism is applied to the confict on the renewal of the reservoir for hydropower generation.