Designing Greenhouse Gases Emissions Trading Institutions : Theory and Experiments

1997年12月的《气候公约京都议定书》为发达国家和正在向市场经济转型的国家确定了温室气体的国家排放目标。作为实现这一目标的机制之一，它授权进行排污权交易。在这项研究项目中，我们研究了如何为温室气体排放交易设计理想的机构。如果排放许可以竞争性均衡价格进行交易，就可以以最低的成本有效地实现《议定书》的目标。然而，《京都议定书》规定，排污权交易应作为国内温室气体减排行动的补充，而补充性一直是主要问题之一。利用博弈论方法，我们研究了欧盟关于补充的具体建议，并发展了关于补充的一般理论。此外，我们还分析了欧盟、美国和日本在制定京都议定书细节谈判中的政治和战略立场。在这些理论分析的基础上，我们利用受试者进行了80多个排污权交易实验。特别是，我们发现减排投资的不可逆性及其投资时滞效应对排污权交易的效率起着非常重要的作用。当减排投资是可逆的，且不存在时滞效应时，我们观察到，无论交易方法和信息的关闭和披露的选择如何，排污权交易都达到了极高的效率。然而，当引入不可逆转的减排投资及其时滞效应时，我们发现排污权交易中的价格动态有两种模式：成功案例和失败案例。这些结果具体阐明了投资不确定性是如何降低市场效率的。

The Kyoto Protocol to the Climate Convention in December 1997 establishes national emission targets for greenhouse gases (GHGs) for advanced countries and countries undergoing the process of transition to market economies. As one of mechanisms in order to implement this goal, it authorizes emissions trading. In this research project, we have examined how to design desirable institutions for GHGs emissions trading. If emissions permits are traded at the competitive equilibrium price, the goal of the Protocol can be attained efficiently with the minimum cost. However, the Kyoto Protocol specifies that emissions trading should be supplement to domestic actions in reducing GHGs emissions, and supplementarity has been one of the major issues. By using a game theoretical method, we investigated the concrete EU proposal on supplementarity and developed a general theory on supplementarity. Moreover, we analyzed the political and strategic positions of the EU, the USA, and Japan in negotiations to design the details of the Kyoto Protocol.Based on these theoretical analyses, we have conducted over eighty experiments on emissions trading using subjects. In particular, we found that irreversibility of abatement investment and its investment time-lag effect play very important roles in terms of efficiency of emissions trading. When abatement investment is reversible and no time-lag effect is introduced, we observed that emissions trading attains extremely high efficiency, regardless of the choice of trading methods and information closure and disclosure. However, when introducing irreversible abatement investment and its time-lag effect, we found two patterns of price dynamics in emissions trading : the "success" case and the "failure" case. These results clarify how investment uncertainty reduces market efficiency concretely.