題目：1. Increasing Returns to Scale and the Incentives to Join a Climate Treaty
2. On the Equivalence of the Nash Bargaining Solution and the Lindahl Equilibrium in Models of Environmental Externalities
主講人：楊自力 教授（紐約州立大學賓漢頓經濟學教授、偉德國際1946bv官網兼職教授、耶魯大學經濟學博士）
時間：2016年1月25日（周一）上午9:30
地點：主樓六層
主講人介紹：
楊自力，主要從事資源與環境經濟學、能源經濟學、經濟建模、應用博弈論、中國經濟等研究工作。同耶魯大學教授William D. Nordhaus合作，發展建立了在世界范圍內最具影響力的氣候變化綜合評估模型（RICE模型），并發表在American Economic Review等重要期刊。RICE模型及其衍生的多個模型在聯合國政府間氣候變化專門委員會（IPCC）歷次報告中被廣泛使用。楊教授獨立發展了將博弈論數值解的概念和算法與氣候經濟綜合評估模型相結合的研究方法，在此開拓性領域居國際領先地位；是世界上第一個將非合作博弈解以及合作博弈解引入大型綜合評估模型的學者；是上世紀90年代麻省理工學院能源實驗室EPPA模型的最主要建模者。
內容介紹：
報告1：Increasing returns to scale (IRS) phenomena are broadly present in international economic relationship. This paper studies the connection between IRS in energy-intensive industries and the attitude towards global climate negotiation. In a model of detrimental externality, the proposition proven states that if some agents maintain IRS with respect to the good generating externality (such as GHG emission), their optimal position in the efficient externality provision can be very close to their inefficient non-cooperative Nash equilibrium position. Numerical simulations validate the conclusion of the proposition. The conclusion explains some fundamental difficulties in international climate negotiations. Finally, the policy implication of IRS on climate negotiation is also discussed.
報告2：The Nash bargaining solution and the Lindahl equilibrium are two important solution concepts in an economy with externality. In this paper, it is proved that the Nash bargaining solution that uses the payoffs of non-cooperative Nash equilibrium as the status quo point is the Lindahl equilibrium without transfers of the problem. Furthermore, the Lindahl equilibrium without transfer can be expressed as the social optimum with the welfare weights set at the cost-sharing ratio retrieved from the Nash bargaining solution. The equivalence connection between this specific Nash bargaining solution and the Lindahl equilibrium without transfers has broad applications in environmental problems. The simulations conducted in the RICE model verify such equivalence relationship and demonstrate the feasibility of its applications in environmental issues. Finally, algorithmic scheme of applying the Nash bargaining solution and the Lindahl equilibrium in environmental modeling are provided in this paper.
（承辦：能源與環境政策研究中心，科研與學術交流中心）
