International environment agreements and the case of global warming

First, this article uses standard welfare economics to illustrate the market failure and policy coordination problems caused by transboundary pollution problems in general and global warming in particular. Secondly, a brief overview is given of the main results obtained by empirical modelling exercises that combine both cost and damage estimates for global warming. Thirdly, the theoretical conclusions are confronted with the reality of ongoing international climate negotiations and the 1997 Kyoto Protocol is evaluated from an economic point of view. Finally, some recommendations are made for the design of future climate agreements.global warming, externalities, international environmental agreements, Nash equilibrium, cost efficiency, participation constraints, equity, Kyoto Protocol

Simulating with RICE Coalitionally Stable Burden Sharing Agreements for the Climate Change Problem

In this paper we test empirically with the Nordhaus and Yang (1996) RICE model the core property of the transfer scheme adv ocated by Germain, Toint and Tulkens (1997). This scheme is designed to sustain full cooperation in a voluntary international environmental agreement by making all countries at least as well off as they would be by joining coalitions adopting emission abatement policies that maximize their coalition payoff; under the scheme no individual country, nor any subset of countries would have an interest in leaving the international environmental agreement. The simulations show that the transfer scheme yields an allocation in the core of the carbon emission abatement game associated with the RICE model. Finally, we discuss some practical implications of the transfer scheme for current climate negotiations.Environmental economics, climate change, burden sharing, simulations, core of cooperative games

Coalition Formation in a Global Warming Game: How the Design of Protocols Affects the Success of Environmental Treaty-Making

We combine the newest concepts of non-cooperative coalition theory with a computable general equilibrium model close to the seminal RICE-model of Nordhaus and Yang (1996) to determine stable coalition structures in a global warming game. We consider three coalition games that allow for the formation of multiple coalitions. The coalition games represent different designs of climate treaty protocols. Counterintuitively, it turns out that treaties based on a unanimous decision rule and exclusive membership lead to superior outcomes than treaties with open membership. We also demonstrate that if coalition formation is not restricted to a single coalition, as this has been done previously in the literature, coalition structures with multiple coalitions will emerge in equilibrium. Most of the regional agreements are superior to single agreements. Moreover, our findings confirm those derived from simpler theoretical models that a cleverly designed transfer scheme can foster cooperation and that from the number of participants the success of a treaty cannot be inferred. They also support a conjecture of theory that in the case of greenhouse gases stable coalition structures (partial cooperation) can close the gap between the global optimum (full cooperation) and the Nash equilibrium (no cooperation) by a substantial amount.design of climate treaty protocol, coalition formation, non-cooperative game theory

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.coalition games, partition function, externalities, sharing schemes

Moral considerations in trading pollution permits.

In this paper we investigate how moral considerations, modelled as identity effects, affects an endogenous pollution permit trading equilibrium, in which governments choose in a non-cooperative way the amount of permits they allocate to their domestic industries. Politicians might feel reluctant to allow unlimited permit trading and/or may prefer that abatement is undertaken domestically due to ethical motivation. However, once governments have chosen permit allocations, firms trade these permits in an international competitive permit market without moral restraints. We show that governments’ moral concerns may actually increase global emissions but this result depends on the precise formulation of the identity function. Finally, we explore how exogenous technological change affects endogenous permit trading equilibria under identity considerations. We show that decreasing costs of abatement technologies may lead countries to overcome their reluctance to trading emission permits.

Moral concerns on tradable pollution permits in international environmental agreements

We investigate how moral concerns about permit trading affect an endogenous pollution permit trading equilibrium, where governments choose non-cooperatively the amount of permits they allocate to domestic industries. Politicians may feel reluctant to allow permit trading and/or may prefer that abatement is undertaken domestically due to moral concerns. This will have an effect on the initial permit allocations, and, therefore, on global emissions. The impact on global emissions depends on the precise formulation of the moral concerns, but under reasonable assumptions, we show that global emissions may increase. Thus, doing what is perceived as good does not always yield the desired outcome. However, this can be offset by restrictions on permit trading when governments have moral concerns about this trade.Tradable emission permits, international environmental agreements, non-cooperative game theory, moral motivation, identity.

New Roads to International Environmental Agreements: The Case of Global Warming

We analyze with an integrated assessment model of climate change the formation of interna-tional environmental agreements (IEAs) by applying the widely used concept of inter-nal & external stability and several modifications of it. We relax the assumptions of a single agreement and open membership rule. It turns out that regional agreements are superior to a single agreement and exclusive is superior to open membership in welfare and ecological terms. Moreover, we show the importance of transfers for successful treaty-making. We relate our results to the design of current and past IEAs as well as to other issues of international policy coordination.Design of climate treaty protocol, Coalition formation, Non-cooperative game theory

An Empirical Assessment of Measures to Enhance the Success of Global Climate Treaties*

We analyze important forces that hamper the formation of successful self-enforcing agreements to mitigate global warming. The analysis combines two modules: a) a computable general equilibrium model that captures the feedback between the economy, environmental damages and the climate system and b) a game theoretic model that determines stable coalitions in the presence of free-riding incentives. We consider two types of measures to enhance the success of international environmental treaty-making: a) transfers, aiming at balancing asymmetric gains from cooperation; b) institutional changes, aiming at making it more difficult to upset stability of a treaty. We find that institutional changes may be as important as transfers and should therefore receive more attention in future international negotiations.design of climate treaty protocol, coalition formation, non-cooperative game theory, integrated assessment model

The European Union's Potential for Strategic Emissions Trading through Minimal Permit Sale Contracts

Strategic market behavior by permit sellers will harm the European Union as the EU as a whole is expected to become a large net buyer of permits in a follow-up agreement to the Kyoto Protocol. In this paper we explore how the EU could benefit from making permit trade agreements with non-EU countries. These trade agreements involve a minimum permit sales requirement complemented by a financial transfer from the EU to the other contract party. Such agreements enable the EU to act strategically in the permit market on behalf of its member states, although each member state is assumed to behave as a price taker in the permit market. Using a stylized numerical simulation model we show that an appropriately designed permit trade agreement between the EU and China can cut EU’s total compliance cost significantly. This result is robust for a wide range of parameterizations of the simulation model.emissions permit, post-Kyoto climate agreement, strategic permit trade

New Roads to International Environmental Agreements: The Case of Global Warming

We analyze with an integrated assessment model of climate change the formation of international environmental agreements (IEAs) by applying the widely used concept of internal& external stability and several modifications of it. We relax the assumptions of a single agreement and open membership rule. It turns out that regional agreements are superior to a single agreement and exclusive is superior to open membership in welfare and ecological terms. Moreover, we show the importance of transfers for successful treaty-making. We relate our results to the design of current and past IEAs as well as to other issues of international policy coordination.design of climate treaty protocol, coalition formation, non-cooperative game theory