Designing international environmental agreements under participation uncertainty

Traditional international environmental agreement (IEA) models usually use some specific contribution rules, which either fail to provide sufficient incentives for cooperation, or ignore the loss from participation uncertainty. Can more general rules overcome these problems and improve the performance of IEAs? This paper analyzes the endogenous determination of contribution rules from a class of general rules through a three-stage coalition formation game under participation uncertainty. In stage one, a designer chooses a contribution rule, which, depending on the size of the signatories’ coalition formed in stage two, specifies the action each signatory should take in stage three. A contribution rule is said to be optimal when it maximizes the expected payoff of signatories. We provide an algorithm to determine an optimal rule. When uncertainty is either sufficiently large or equal to zero, the optimal rule coincides with some existing rules in the literature. However, when the uncertainty is neither large nor small, the optimal rule outperforms other rules in terms of signatories’ payoff.     

Public good agreements under the weakest‐link technology

We analyze the formation of public good agreements under the weakest‐link technology. Whereas policy coordination is not necessary for symmetric players, it matters for asymmetric players; however, this fails in the absence of transfers. By contrast, with a transfer scheme, asymmetry may be an asset for cooperation. We characterize various types and degrees of asymmetry and relate them to the stability of self‐enforcing agreements. Asymmetric distributions of autarky public good provision levels (also representing asymmetric interests in cooperation) that are positively skewed tend to be conducive to the stability of agreements. We show that under such conditions, even a coalition including all players can be stable. However, asymmetries that foster stability (instability) tend to be associated with low (high) gains from cooperation.     

Cost sharing with multiple technologies

We study cost sharing problems where gains from cooperation can come from the presence of other agents, such as when agents share their technologies. A simple model is built, where economies of scale are eliminated in order to study this effect. We use as the key axiom the property that, if an agent does not improve the technology of any coalition he joins, he should not get any part of the gain from cooperation. With properties of linearity and symmetry, this axiom characterizes a well-defined set of rules. From this set, we propose a rule derived from the familiar Shapley value. We show that it is the only rule in that set satisfying an upper-limit property on individual cost allocations or a monotonicity property when technology improves. We also derive a distinct rule using a property that ensures that no coalition has an incentive to manipulate the individual demands of its members.     

Cost sharing with multiple technologies

We study cost sharing problems where gains from cooperation can come from the presence of other agents, such as when agents share their technologies. A simple model is built, where economies of scale are eliminated in order to study this effect. We use as the key axiom the property that, if an agent does not improve the technology of any coalition he joins, he should not get any part of the gain from cooperation. With properties of linearity and symmetry, this axiom characterizes a well-defined set of rules. From this set, we propose a rule derived from the familiar Shapley value. We show that it is the only rule in that set satisfying an upper-limit property on individual cost allocations or a monotonicity property when technology improves. We also derive a distinct rule using a property that ensures that no coalition has an incentive to manipulate the individual demands of its members.     

Coming and going: Experiments on endogenous group sizes for excludable public goods

When a public good is congestible, individuals wanting to provide the public good face challenges in forming groups of optimal size, selecting the members of the group, and encouraging members to contribute for the public good. We conduct a series of experiments in which subjects form groups using three different entry and exit rules. The experimental results are analyzed in terms of group size, the level of public good provision, social efficiency, congestion and group stability. We find that entry restriction improves the average earnings for some individuals compared to free entry/exit or restricted exit. For a given group size, individuals under the restricted entry rule contribute more for the provision of the collective good. Also, for a given average contribution level of group members, subjects under the restricted entry rule suffer less from the congestion problem and are better able to form groups of sizes closer to the optimal.     

Stability of international environmental agreements under isoelastic utility

There is now a growing consensus that ratifying International Environmental Agreements (IEAs) is the most effective way to tackle transboundary pollution problems. While the social benefit function (SBF) critically affects emission choices as well as decisions to ratify IEAs, the related economic literature has mainly concentrated on scenarios where the marginal SBF is linear. Using climatic data, I find that the linear marginal SBF case does not match data and isoelastic SBFs fit data better. In the more realistic, but not yet explored, context of isoelastic SBFs, I reconsider incentives to ratify IEAs. My analysis gives rise to novel conclusions. For instance, changes in the scale of damages do not affect the level of cooperation. When the scale of damages is small, variations of the SBF parameter reveal that large coalitions including the coalition of all countries are stable, but only when the potential gain from cooperation is sufficiently high.     

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.     

The strategy-proof provision of public goods under congestion and crowding preferences

We examine the strategy-proof provision of excludable public goods when agents care about the number of other consumers. We show that strategy-proof and efficient social choice functions satisfying an outsider independence condition must always assign a fixed number of consumers, regardless of individual desires to participate. A hierarchical rule selects participants and a generalized median rule selects the level of the public good. Under heterogeneity in agents’ views on the optimal number of consumers, strategy-proof, efficient, and outsider independent social choice functions are much more limited and in an important case must be dictatorial.     

Collusion-Proof Samuelson Conditions for Public Goods

We analyze a public good problem when agents form a grand coalition to promote their own collective goal instead of that of society as a whole. When collusion takes place under symmetric information , the collusion-proof Samuelson rule takes a simple form that is close to an ex ante cost-benefit analysis . Then, we analyze the case where agents collude under asymmetric information . First, we describe the set of collusion-proof allocations. Second, we establish the collusion-proof Samuelson rule that highlights the role of coalitional virtual valuations . Asymmetric information within the coalition allows the principal to recover some flexibility in the design of the optimal policy. We finally discuss the nature of the inefficiency created by the agents' collusive behavior and the scope of their ex ante gain in forming a coalition.     

Sharing the surplus: An extension of the Shapley value for environments with externalities

Economic activities, both on the macro and micro level, often entail wide-spread externalities. This in turn leads to disputes regarding the compensation levels to the various parties affected. We propose a method of deciding upon the distribution of the gains (costs) of cooperation in the presence of externalities when forming the grand coalition is efficient. We show that any sharing rule satisfying efficiency, linearity, dummy player and a strong symmetry axioms can be obtained through an average game. Adding an additional axiom, we identify one unique rule satisfying these properties.     

Taxes or Fees? The Political Economy of Providing Excludable Public Goods

This paper provides a positive analysis of public provision of excludable public goods financed by uniform taxes or fees. Individuals differing in preferences decide, using majority rule, the provision level and financing instrument. The decisive voter has median preferences in a tax regime, but generally has above median preferences in a fee regime. Numerical solutions indicate that populations with uniform or left‐skewed distributions of preferences choose taxes, while a majority coalition of high‐ and low‐preference individuals prefer fees when preferences are sufficiently right skewed. Public good provision and welfare under fees exceeds that under taxes in the latter case.     

PUBLIC GOOD PROVISION WITH CONSTITUTIONAL CONSTRAINT

This article studies the public good provision problem, in which the principal faces a constitutional constraint in the sense that in order for a public good provision mechanism to be implemented, it must first be approved by agents under a prespecified voting rule. I find that as long as the voting rule is not the unanimity rule, the principal can propose a mechanism such that first‐best efficiency of provision of the public good is achieved. I also consider various constraints, such as prohibition of discriminatory mechanisms and the existence of vote buying, and discuss optimal voting rules in these situations.     

Coordination and the Provision of Discrete Public Goods by Correlated Equilibria

The strategic analysis of the private provision of a discrete public good has shown the existence of multiple Nash equilibria with the efficient number of players voluntarily contributing. However the coordination issue is left unexplained by this literature. The experimental evidence shows that communication among players is helpful in achieving cooperation. We claim that, from the theoretical point of view, this is equivalent to playing correlated equilibria in an extended public good game with communication, modeled as Chicken. We characterize such equilibria as feasible coordination mechanisms to achieve public goods provision in the general contribution game. We further introduce a second kind of game characterized by payoff externalities that may persist after the minimal threshold of contributors is achieved. While it is easy to show the existence of Pareto efficient correlated equilibria in the first game, in the second one players face incentive problems such that a first best cannot always be an equilibrium. Nevertheless there exist correlated equilibria that can qualify as incentive efficient mechanisms, once free riding is seen as a moral hazard issue. Finally, with an example, we discuss the impact of coalition formation in our framework.     

Voluntary Participation and Provision of Public Goods in Large Finite Economies

We consider a public good provision game with voluntary participation. Agents participating in the game provide a public good and pay the fees according to a mechanism (allocation rule), while nonparticipants can free‐ride on the participants. We examine how the equilibrium public good provision level is affected by enlarging the population of an economy. We introduce a condition for an allocation rule, the asymptotic uniform continuity in replication (AUCR), which requires that small changes in the population must yield only small changes in the public good provision and which is satisfied by many mechanisms. We show that under AUCR, the equilibrium level of the public good converges to zero as the economy is replicated in the sense of Milleron.     

Public goods and public bads

In many empirically relevant situations agents in different groups are affected by the provision of a public characteristic in divergent ways. Whereas for one group it represents a public good, it is a public bad for another group. Applying Cornes and Hartley's aggregative game approach, we analyze a general model in which such contentious public characteristics are present and are provided cooperatively. In particular, we establish neutrality results with respect to redistribution and growth of income, infer the effects of preference changes and coalition formation, and present a technology paradox. Finally, we compare the outcome of voluntary provision of the contentious public characteristic with the Pareto‐optimal solution, highlighting a potential conflict between equity and efficiency in this case.     

Toward an efficiency rationale for the public provision of private goods

Public provision of a private goods is justified on efficiency grounds in a model with no redistributive preferences. A government’s involvement in the provision of a private good generates information about preferences that facilitates more efficient revenue extraction for the provision of public goods. Public provision of the private good improves economic efficiency under a condition that is always fulfilled under independence and satisfied for an open set of joint distributions. The efficiency gains require that consumers cannot arbitrage the publicly provided private good, so our analysis applies to private goods where it is easy to keep track of the ultimate user, such as schooling and health care, but not to easily tradable consumer goods.     

Exchange Rules and the Incentive Compatibility of Choice Experiments

The incentive properties of stated-preference surveys continue to be a central debate in the valuation of public goods. The majority of empirical studies have focused on incentive properties of contingent valuation questions in relation to situations where answers have monetary consequences. This research explores the incentive properties of repeated, attribute-based choice questions when subjects are provided with an explicit connection between choices and outcomes. Two market/provision-rules are investigated: a posted-price market and a plurality-rule vote. These two provision rules are contrasted to treatments in which no provision rule is discussed—subjects are simply asked to choose their preferred alternative. These three hypothetical choice treatments are compared with a binding choice treatment. While none of the public good treatments are theoretically incentive compatible, we include a comparison of hypothetical and binding choices for a private-good that is incentive compatible. The private good experiments indicate that marginal willingness to pay (WTP) estimates from the hypothetical treatment are larger, but not statistically different than corresponding estimates in the binding choice treatment. Results for the public good experiments indicate that marginal WTP estimates from the hypothetical treatments are much larger, and statistically different than corresponding estimates in the binding choice treatment. The bias is largest when no provision rule is discussed. The bias is reduced with the inclusion of a provision rule, but surprisingly, there was no difference across provision rule treatments. Overall, our results indicate that choice experiments involving a public good should include a provision rule to reduce bias, but the resulting marginal WTP estimates may still be more biased, on average, than those arising from contingent valuation survey formats.     

Public good provision with optimal and non-optimal commodity taxation: The single-consumer case

The criterion for welfare-enhancing changes in the level of public good provision is studied in a model with optimal, and more general, commodity tax structures. The welfare rule is sensitive to the precise nature of interactions between public spending and (ordinary or compensated) demands for taxed goods.     

The Time‐Consistent Public Goods Provision

In this study, we reconsider the optimal nonlinear tax problem with the public good from the perspective of the commitment issue and examine how it affects the condition of the public good provision. We show that the Samuelson rule should be modified when the government cannot commit and the skill types of taxpayers are revealed in the first period. This is true even if the preference of the taxpayers is separable and additive with respect to consumption and leisure. Our analysis also shows how the lack of commitment affects the formula of the marginal cost of public funds and the level of public good provision. Our findings imply that the level of the public good may be excessive in comparison to the case where the government can commit to its tax policy.