Michael Finus

Game Theoretic Research on the Design of International Environmental Agreements: Insights, Critical Remarks, and Future Challenges

In recent years, the number of publications that analyze the formation and stability of international environmental agreements (IEAs) using the method of game theory has sharply increased. This paper reports on some recent results that shall demonstrate the usefulness but also the limitation of game theory for the analysis of IEAs. It restricts attention to the class of non-cooperative membership models and focuses on the relation between different designs and the success of IEAs. Results are illustrated for the climate change problem with the empirical Stability of Coalitions (STACO) model developed by Dellink et al. (2004). Subsequently, some features of actual treaty-making not considered with this model are discussed with reference to the literature and their importance for future research is highlighted.

Toward a positive theory of coalition formation and endogenous instrumental choice in global pollution control

The paper analyzes the coalition formation process in a global emission game with asymmetric countries where the number of signatories, the abatement target and the policy instrument are chosen simultaneously. Exemplarily, a uniform emission reduction quota and an effluent charge are considered. Stability is analyzed in a supergame framework by applying the concept of coalition-proofness. The analysis also considers the impact of impatient agents, restricted and simple punishment profiles. Two main results may be mentioned: First, paradoxically, IEAs achieve only little (if signed at all) if the externality problem is distinct. Second, our model helps to explain the frequent appearance of emission quotas in international pollution control despite the recommendations by economists to use market-based instruments like effluent charges.

The Oslo Protocol on sulfur reduction: the great leap forward?

The increasing number of international environmental agreements (IEAs), and the fact that under some agreements emissions have been reduced beyond agreed targets, are frequently viewed as success stories of international cooperation. We argue that success can only be measured if abatement targets under an IEA are compared with estimated abatement levels in the absence of a treaty, and are evaluated in terms of costs and benefits. We analyze the Oslo Protocol on sulfur reduction, showing that this IEA is not the great leap forward when compared with the calculated Nash equilibrium and the social optimum. However, we also demonstrate that under the Oslo Protocol, more ambitious targets could not have been realized due to strong free rider incentives.

Endogenous coalition formation in global pollution control: a partition function approach

This important book, written by some of the leading scholars in the field, provides a comprehensive overview of recent advances in coalition theory and presents both the latest theoretical developments and novel applications in the field of economics.

An Almost Ideal Sharing Scheme for Coalition Games with Externalities

We propose a class of sharing schemes for the distribution of the gains from cooperation for coalition games with externalities. In the context of the partition function, it is shown that any member of this class of sharing schemes leads to the same set of stable coalitions in the sense of d’Aspremont et al. (1983). These schemes are “almost ideal” in that they stabilize these coalitions which generate the highest global welfare among the set of “potentially stable coalitions”. Our sharing scheme is particularly powerful for economic problems that are characterized by positive externalities from coalition formation and which therefore are likely to suffer from severe free-riding.

Renegotiation-proof equilibria in a global emission game when players are impatient

In a two-country model, in which countries differ with respect to the perception of environmental damages and abatement costs, the stability of international environmental agreements is analyzed in a dynamic framework. Three types of agreements are considered: A socially optimal solution, a uniform emission tax (a tax equally applied in both countries) and a uniform emission reduction quota (an equal percentage emission reduction from a base year). Stability is checked for these agreements according to the concept of renegotiation-proofness. It is shown that the stability requirements depend crucially on the parameters defining the interests of the two countries and the type of agreement. Moreover, it is demonstrated that if punishment options are restricted for some reason the stability of an agreement may suffer. One important result of the paper is that if countries exhibit asymmetric interests, stability in the quota regime is higher than in the tax regime and in the social optimum. This might explain why emission reduction quotas have been so popular in international politics despite recommendations of economists to use market-based instruments.

Quotas May Beat Taxes in a Global Emission Game

Economists have persistently argued that market-based instruments are better suited than command and control instruments (CAC) to achieve pollution abatement targets cost-effectively. However, this advice has not yet fallen on fertile soil. CAC is the predominant instrument in practical environmental policy. The paper attempts to give an explanation for this observation by analyzing two countries negotiating emission reductions in a world with “typical” institutional restrictions. Negotiations are assumed to be either on a uniform emission reduction quota or a uniform emission tax. Counterintuitively, it turns out that in such a second-best world an agreement under a cost-inefficient quota regime may be superior to an efficient tax agreement with respect to ecological and welfare criteria. Moreover, in contrast to a quota agreement, a tax agreement may not be feasible and stable if countries exhibit asymmetric cost-benefit structures.

Game Theory and International Environmental Cooperation: Any Practical Application?

Many researchers have found game theory a useful method for analyzing international environmental problems. However, game theory has been criticized for being too theoretical, abstracting from too many practical problems and being based on very specific assumptions. This article tries to qualify this critic. First, it lays out the fundamental assumptions underlying the game theoretical analysis of international environmental problems. Second it summarizes important findings which help to explain the difficulties of cooperation and discusses remedies. Chapter 3 looks at measures to avoid asymmetric welfare distributions and to enforce an IEA. Chapter 4 discusses policy instruments in global pollution control and chapter 5 summarizes the results on the formation of coalitions. Third, the results of chapters 3, 4 and 5 are critically reviewed. On the one hand, open issues with respect to the theoretical analysis are characterized. On the other hand, practical problems which are not covered by theory are mentioned and evaluated as to their effect to influence policy conclusions. Fourth, the theoretical results and the derived conclusions of chapters 3 to 5 are applied to the analysis of the Kyoto-Protocol (chapter 6). The article stresses the intuition behind all results, though formal proofs of new results are given.

DO ABATEMENT QUOTAS LEAD TO MORE SUCCESSFUL CLIMATE COALITIONS

In this paper we study the effect of different treaty designs on the success of international environmental agreements (IEAs). We analyze the standard assumption of an efficient abatement scheme and three uniform abatement quota schemes. Apart from analytical results, the analysis is supported by simulations based on the STACO (stability of coalitions) model. It turns out that quota agreements where the members decide by majority or unanimity voting are successful in overcoming free-rider incentives within an IEA. Finally, our results provide a rationale for the application of uniform abatement quotas in IEAs.

An empirical test of new developments in coalition theory for the design of international environmental agreements

We consider new developments in coalition theory for the design of international environmental agreements (IEAs). Applying an empirical model on climate change that comprises benefit and cost estimates from abatement for 12 world regions, we analyze how the design of an agreement affects the success of self-enforcing IEAs. We analyze single versus multiple coalitions, open versus exclusive membership with majority and unanimity voting, and no transfers versus transfers with four different transfer schemes.