The stability likelihood of an international climate agreement

Results derived from empirical analyses on the stability of climate coalitions are usually very sensitive to the large uncertainties associated with the benefits and costs of climate policies. This paper provides the methodology of Stability Likelihood (SL) that links uncertainties about benefits and costs of climate change to the stability of coalitions. We show that the concept of SL improves upon the robustness and interpretation of stability analyses. Moreover, our numerical application qualifies conclusions from a recent strand of literature based on stylised models with ex-ante symmetric players that learning has a negative impact on the success of coalition formation in context of uncertainty.      

Socially Subjective Equilibrium in Strategic Form Games

This study provides a new framework and a new equilibrium concept, which are able to describe the situation where people have various images of the society and have various solution concepts for social outcomes, and where people accept the social outcomes. In socially subjective equilibrium, people have a coherence of their own norms in two senses. One is the consistency of the norm itself. Imagined outcomes should satisfy a certain (subjective) solution concept. The other is the consistency between the imagined outcomes and realized one. These are the main features of our equilibrium concept. This paper forms a part of my doctoral thesis, which is titled “On socially subjective equilibrium”. The first person I would like to thank is my direct supervisor Professor Ken Urai (Osaka University). I obtained a basic idea of the main concept of my doctoral thesis, that is, the solution concept scheme, from Professor Urai. I am grateful to Professor Hiroaki Nagatani (Osaka University) and Professor Ken-Ichi Shimomura (Kobe University), who monitored my works and took efforts in providing me with valuable comments on earlier versions of my thesis. I also obtained a fruitful advice from Professor Kenichi Amaya (Kobe University). Lastly, I specially thank to Kozo Shiraishi (Osaka University).     

Renegotiation-Proof Climate Agreements with Full Participation: Conditions for Pareto-Efficiency

Recent contributions show that climate agreements with broad participation can be implemented as weakly renegotiation-proof equilibria in simple models of greenhouse gas abatement where each country has a binary choice between cooperating (i.e., abate emissions) or defecting (no abatement). Here we show that this result carries over to a model where countries have a continuum of emission choices. Indeed, a Pareto-efficient climate agreement can always be implemented as a weakly renegotiation-proof equilibrium, for a sufficiently high discount factor. This means that one need not trade-off a “narrow but deep” treaty with a “broad but shallow” treaty.     

Altruism,Warm Glow and the Willingness-to-Donate for Green Electricity: An Artefactual Field Experiment

The ongoing liberalization of electricity markets in most western countries forms the background of our artefactual field experiment. Using a Cheap talk design [R.G. Cummings and L.O. Taylor. American Economic Review 89 (1999) 649–665] with supplementary monetary incentives, we test for presence of “warm glow” motivations [J. Andreoni. Journal of Political Economy 97 (1989) 1447–1458; Economic Journal 100 (1990) 464–477] in the willingness-to-donate for electricity generated from renewables. Our data from 200 participants supports impure altruism, that is, individuals benefit from both contributing to environmental quality and its current level when opting in favor of green electricity. Furthermore, we find evidence of crowding-out as well as crowding-in effects. Depending on the knowledge of people about electricity markets and the types of electricity contracts offered, “all-or-none” contracts are most likely to bring about crowding-out effects.     

基于非合作博弈的期货市场策略分析

本文基于非合作博弈的方法,通过建立非合作博弈模型对期货市场多空双方的行动策略进行分析,分别就完全信息博弈、不完全信息博弈和不完美信息博弈三种不同的博弈环境,讨论了多空双方在不同的市场形势下的行动策略、博弈的均衡及结果。分析结果表明在不同的博弈环境下,无论是均势市场、多头市场还是空头市场,资金和信息对于期货市场多空双方的博弈策略具有至关重要的影响。基于此结论,本文进一步提出,为了获得资金优势和信息优势,建立期货投资基金,形成博弈联盟是一种有效的博弈形式,以此为基础的合作博弈分析方法是分析联盟博弈的有效方法。     

Two simple proofs of the feasibility of the linear tracing procedure

Summary. Theories of equilibrium selection in non-cooperative games, as well as the notion of risk dominance, depend heavily on the so-called linear tracing procedure. This is the first paper to give direct, simple proofs of the feasibility of the linear tracing procedure. The first proof utilizes a result that is related to Kakutani's fixed point theorem and that is an extension of Browder's fixed point theorem. The second proof shows that it is even possible to avoid the use of correspondences. Received: June 8, 1998; revised version: November 8, 1998     

Whatever you say, your reputation precedes you: Observation and cheap talk in the trust game

Behavior in trust games has been linked to general notions of trust and trustworthiness, important components of social capital. In the equilibrium of a trust game, the investor does not invest, foreseeing that the allocator would keep all of the returns. We use a human-subjects experiment to test the effects of changes to the game designed to increase cooperation and efficiency. We add a pre-play stage in which the investor receives a cheap-talk message from the allocator, observes the allocator's previous decision, or both. None of these changes alter the game's theoretical predictions. We find that allowing observation results in substantially higher cooperation and efficiency, but cheap talk has little effect.