A Good Opening: The Key to Make the Most of Unilateral Climate Action

In this paper we argue that when a subgroup of countries cooperate on emission reduction, the optimal response of non-signatory countries reflects the interaction between three potentially opposing factors, the incentive to free-ride on the environmental benefits of cooperation, the incentive to expand energy consumption, and the incentive to adopt the cleaner technologies introduced by the coalition. Using an Integrated Assessment Model with a game-theoretic structure we find that the equilibrium abatement of the coalition composed by OECD countries would be moderate, in line with the Pledges subscribed in Copenhagen, but increasing. The mitigation strategy would consist of investments in energy R&D and deployment of cleaner technologies with high learning potentials. International knowledge and technology externalities would facilitate the diffusion of cleaner technologies in non-signatory countries, offsetting the free-riding incentive and reducing their emissions. If the OECD group curbs emissions beyond the optimal equilibrium level, reaching reduction rates between 40 and 45 % below 2005 levels in 2050, the benefits of technology externalities would no longer compensate the effect of lower fossil fuel prices. Our results suggest that a moderate unilateral climate policy could induce a virtuous behaviour in non-signatory countries and that policies promoting the international transfer of technologies and knowledge could represent an effective complement to mitigation targets.     

Trade and Global Pollution in Dynamic Oligopoly with Corporate Environmentalism

This paper examines the effects of international trade in the presence of dynamic oligopolistic competition where the stock of global pollution has a negative welfare effect and the oligopolists' objectives may include society's pollution damage as well as private profits. In a symmetric case where the number of firms, emission coefficient, and firms' environmental consciousness are the same in two countries, an opening of trade unambiguously improves each country's welfare in the short run. In the long run, however, trade increases the stock of global pollution and hence, whether opening of trade is beneficial depends on the parameters of the economy. If there are asymmetries between countries, the short‐run gains from trade in both countries are not necessarily guaranteed, because trade liberalization may increase output in one country and reduce it in the other. Moreover, free trade may result in lower pollution stock than under autarky.     

The Impact of Equity-preferences on the Stability of International Environmental Agreements

This paper uses a coalition formation model to explore how equity considerations affect countries’ cooperation on global environmental issues, e.g. on climate change. When developing countries are exempted from obligations to reduce their emissions, I find that opening them for abatement projects financed by industrialized countries changes the incentives to cooperate in a way which can increase emissions and decrease welfare. Equity- concerns in industrialized countries regarding the difference between their per capita emission levels and those of developing countries lead to increased abatement but do not qualitatively change the incentives to cooperate. Inequality-aversion with respect to differences to abatement targets across industrialized countries generally induces larger coalition sizes and stricter abatement. Here, the inclusion of developing countries improves upon the prospects of cooperation.     

Barriers to Global Free Trade through Bilateral Agreements

This paper examines the formation of bilateral free trade agreements (FTAs) in the context of a dynamic noncooperative bargaining game with a random proposer. We show that global free trade (a grand coalition) does not necessarily occur unless transfer payments among countries are allowed. When transfer payments are possible, bilateral FTAs always achieve global free trade, but the ex‐ante and ex‐post inequalities of social welfare among countries are larger than those when all countries are independent because of the strategic bargaining behavior.     

A Dynamic Model for International Environmental Agreements

In this paper we develop a model that uses a dynamic framework to analyze the process through which countries join international environmental agreements (IEAs). In the model, while all countries suffer from the same environmental damage as a result of total global emissions, non-signatory countries decide on their emission levels by maximizing their own welfare, whereas signatory countries decide on their emission levels by maximizing the aggregate welfare of all signatory countries. It is assumed that signatory countries will be able to punish non-signatories, at some cost to themselves. When countries decide on their pollution emissions, they account for the evolution of the stock of pollution over time. Moreover, we propose a mechanism to describe how countries reach a stable IEA. The model is able to capture situations characterized by partial cooperation within an IEA that is stable over time. It also captures situations where all countries participate in a stable agreement, and situations where no stable agreement is feasible. Where more than one possibility coexist, the long-term outcome of the game depends on the initial conditions (i.e., the initial number of signatory countries and pollution level).     

Stability of international climate coalitions — A comparison of transfer schemes

This paper studies the impact of pragmatic and optimal transfer schemes on the incentives for regions to join international climate agreements. With an applied model that comprises twelve world regions we investigate: (i) a benchmark without transfers, (ii) scenarios with allocation-based rules where coalition members receive tradable emission permits proportional to initial or future emissions, (iii) scenarios with outcome-based rules where the coalition surplus is distributed proportional to emissions, and (iv) a scenario based on an optimal sharing rule where the coalition surplus is distributed proportional to outside option payoffs.We find that well-designed transfer schemes can stabilise larger coalitions and increase global abatement levels. In our applied setting we find that for allocation-based and outcome-based rules only small coalitions are stable, and, in the case of grandfathered emission permits, there is no stable coalition at all. Some obstacles associated with grandfathered emission permits can be overcome by incorporating the expected growth of emissions in developing countries in the distribution of emission permits. For the optimal transfer scheme we find that larger coalitions, which include key players such as the United States and China, can be stable, but no transfer scheme is capable of stabilising the Grand Coalition.     

Rivalry, Exclusion, and Coalitions

This paper analyzes a model where groups can attain exclusive ownership of a resource by means of a contest. We show that more concave production technologies and more egalitarianism within groups induce higher levels of social conflict. We then study endogenous coalition formation. Under cooperative exploitation of the resource, the grand coalition is the efficient partition but there exists a strong tendency toward bipartisan conflicts. Under noncooperative exploitation, conflict can ex ante Pareto dominate peaceful access and it becomes more difficult to support the grand coalition as a stable structure.     

Global public goods and coalition formation under matching mechanisms

This paper links coalition theory with matching mechanisms in the presence of global public goods among heterogeneous players. This matching coalition may achieve Pareto‐improving outcomes while avoiding side payments. The paper characterizes conditions of coalition profitability and stability at both interior and corner equilibria. It is generally much harder to satisfy stability conditions than profitability conditions. A matching coalition is more profitable but less stable with a larger matching rate. Empirically there is no stable coalition but this can be overcome by introducing reputation mechanisms. There always exists a stable grand matching coalition if players value their reputation. The matching coalition faces a trade‐off between matching depth and breadth.     

Is there a case for carbon-based border tax adjustment? An applied general equilibrium analysis

Concern that unilateral Greenhouse Gas (GHG) emission reductions could foster carbon leakage and undermine the international competitiveness of domestic industry has led to growing calls for carbon-based Border-Tax Adjustments (BTAs). This article uses a global general equilibrium model to assess the economic effects of BTAs and comes to three main conclusions. First, BTAs can reduce carbon leakage if the coalition of countries taking action to reduce GHG emissions is small, because in this case leakage (while typically small) mainly occurs through international trade competitiveness losses rather than through declines in world fossil fuel prices. Second, even though the economic effects of BTAs vary somewhat depending on how they are implemented, their welfare impact is typically small, and slightly negative at the world level. Third, and perhaps more strikingly, BTAs do not necessarily curb the output losses incurred by the domestic Energy Intensive-Industries (EIIs) they are intended to protect in the first place. This is in part because EIIs in industrialized countries make important use of carbon-intensive intermediate inputs produced by EIIs in other geographical areas. Another, deeper explanation is that EIIs are ultimately more adversely affected by the existence of a carbon price itself than by any international competitiveness losses. These findings are shown to be robust to key model parameters, country coverage, targets and design features of BTAs.     

The biodiversity conservation game with heterogeneous countries

Biodiversity is an essential resource, which we classify as conditionally-renewable. In order to achieve conservation and sustainable use of biodiversity virtually all nation states signed the United Nations Convention on Biological Diversity. In this paper we investigate how the heterogeneity of countries in regard to ecosystems and wealth influences the stability of international biodiversity conservation agreements both without and with transfers. We further examine the effect of different degrees of ecosystem substitutability. We model a coalition formation game with players that have a continuous conservation choice. The conservation benefit is dependent on wealth and ecosystem quality. Aggregation of global benefits respects differences in ecosystem substitutability. In case of transfers, a fund redistributes coalition benefits according to a sharing rule. The main finding is that in the absence of transfers, compared to the homogeneous situation, heterogeneity in ecosystems and wealth reduces the size of a stable coalition. The destabilising effect is stronger the higher the ecosystem substitutability. Optimal transfers facilitate a large stable coalition.     

Endogenous Minimum Participation in International Environmental Treaties

Many international treaties come into force only after a minimum number of countries have signed and ratified the treaty. Minimum participation constraints are particularly frequent in the case of environmental treaties dealing with global commons, where free-riding incentives are strong. Why do countries that know they have an incentive to free-ride accept to “tie their hands” through the introduction of a minimum participation constraint? This article addresses the above issues by modeling the formation of an international treaty as a three-stage non-cooperative coalition formation game. Both the equilibrium minimum participation constraint and the number of signatories—the coalition size—are determined. This article, by showing that a non-trivial partial coalition, sustained by a binding minimum participation constraint, forms at the equilibrium, explains the occurrence of minimum participation clauses in most international environmental agreements. It also analyses the endogenous equilibrium size of the minimum participation constraint.     

Transboundary Pollution in the Black Sea: Comparison of Institutional Arrangements

This paper analyses the transboundary pollution between Romania and Ukraine, coastal states along the Black Sea, and studies the welfare consequences of institutional arrangements for controlling this problem. To achieve this goal, we use a dynamic and strategic framework. We compare in terms of total welfare for two countries a first-best case with three different institutional arrangements: the non-cooperative game of countries, the uniform emission policy and the constant emission policy as proposed by the Black Sea Commission. Our findings indicate that the non-cooperative game provides a better level of total welfare than the other rules.     

A note on stable and sustainable global tax coordination with Leviathan governments

Itaya et al. (2014) study the conditions for sustainability and stability of capital tax coordination in a repeated game model with tax-revenue maximizing governments. One of their major results is that the grand tax coalition is never stable and sustainable. The purpose of this note is to prove that there are conditions under which the grand tax coalition is stable and sustainable in Itaya et al.'s model.     

International Environmental Agreements—The Role of Foresight

The present paper attempts to bridge the gap between the cooperative and the non-cooperative approach employed to examine the size of stable coalitions, formed to address global environmental problems. We do so by endowing countries with foresightedness, that is, by endogenizing the reaction of the coalition’s members to a deviation by one member. We assume that when a country contemplates withdrawing or joining an agreement, it takes into account the reactions of other countries ignited by its own actions. We identify conditions under which there always exists a unique set of farsighted stable IEAs. The new farsighted IEAs can be much larger than those some of the previous models supported but are not always Pareto efficient.     

TECHNOLOGY CHOICE AND ENVIRONMENTAL AWARENESS IN A TRADE AND ENVIRONMENT CONTEXT*

Assuming that an environmentally‐friendly technology not only reduces pollution emissions but also strengthens the preference of consumers for goods produced with such a technology, we show that a legally stipulated choice of cleaner technologies, requiring resources and hence reducing output, can improve the welfare of the economy even when other economies do not choose such technologies, and that the driving force can be the terms‐of‐trade effect. Therefore, even a unilateral regulation on the choice of technology would be approved in the economy when the environmental awareness of consumers is sufficiently raised.     

Cooperation in international environmental negotiations due to a preference for equity

This paper demonstrates that cooperation in international environmental negotiations can be explained by preferences for equity. Within a N-country prisoner’s dilemma in which agents can either cooperate or defect, in addition to the standard non-cooperative equilibrium, cooperation of a large fraction or even of all countries can establish a Nash equilibrium. In an emission game, however, where countries can choose their abatement level continuously, equity preferences cannot improve upon the standard inefficient Nash equilibrium. Finally, in a two stage game on coalition formation, the presence of equity-interested countries increases the coalition size and leads to efficiency gains. Here, even a stable agreement with full cooperation can be reached.     

Dynamic Games of Environmental Policy in a Global Economy: Taxes versus Quotas

The effects of environmental policy on the global environment as an international public good with a stock externality and national welfare are examined in a model with trade in a polluting commodity. The welfare effects of environmental policy, decomposed into terms of trade, abatement cost, and environmental damage effects, induce governments to adopt a strategic use of their policy measures. In the absence of international cooperation on environmental policy, it is demonstrated that the emission tax game brings about larger strategic distortions than the emission quota game.     

Co-operation and Unilateral Commitment in the Presence of Global Environmental Problems

This paper focuses on the link between group co-operation and unilateral commitment of some countries in the presence of global environmental problems. We show that in case of a failure of negotiation, some countries can decide to commit unilaterally and reduce their emissions. We call this behaviour precautionary commitment. Absence of international agreement does not mean global defection from the environmental issue.We also show that the emergence of a non-co-ordinatedglobal co-operation can result from a strategic actionfrom the members of the coalition. The insiders of the coalition create an incentive for the non-members to reduce without co-ordinating their emissions.     

Taxation of a Polluting Non-renewable Resource in the Heterogeneous World

This paper extends the literature on the taxation of polluting exhaustible resources by taking international heterogeneities and national tax-setting into account. We propose a two-country Romer model of endogenous growth in which the South is endowed with the stock of an essential polluting non-renewable resource and world economic growth is driven by a northern research sector. We consider the stock of pollution as affecting global welfare. First, we characterize the optimal environmental taxation policies. Second, we examine the impacts of national taxes. Their time profile determines the extraction path, the dynamics of pollution accumulation and that of world output. Their respective levels entail inter-country interactions by altering the efficiency of the world resource allocation, the tax revenues and the resource rents. We study isolatedly the distortional and distributional effects of local taxes. Then, we completely assess the overall impact of a unilateral tax increase. Finally, we find that, even if heterogeneous countries coordinate their taxation policies to correct the global environmental problem, their divergent strategic interests cause another global, non-environmental distortion in the allocation of the resource.     

Piecemeal Multilateral Environmental Policy Reforms under Asymmetric Oligopoly

We develop a general two‐country model with oligopolistic interdependence in which a fixed number of firms make their output and emission decisions simultaneously. We examine the effect of multilateral reforms of emission taxes on global emission levels. With sufficient asymmetry in pollution intensities between the two countries, a proportional multilateral increase in emission tax rates can increase global emission levels. However, a multilateral equal increase of emission tax rates unambiguously reduces global emission levels. We also consider the case of free entry and exit of firms, and find a rule of multilateral reforms which unambiguously lowers total emission levels.