This paper examines the interaction of two types of provisions in international environmental agreements: an identity-based minimum participation clause (MPC) and an equal treatment provision. While MPCs have been widely studied in the context of multilateral agreements, this paper is the first to formally introduce treaties specifying equal proportional reductions from the no-treaty equilibrium for all participants. Does the presence of these two provisions assist or impede the formation and efficiency of the grand coalition? In cases of equal treatment and heterogeneity of agents, smaller coalitions may result in higher welfare than requiring the grand coalition. Using game theoretic analysis of a set of games, this paper gives a set of sufficient conditions for this welfare result to hold in a one-shot negative externality coalition game and presents examples of when smaller agreements do, and do not, improve upon unanimity. Furthermore, this paper focuses on how the choice of negotiation rules affects the optimal set of signatories. By specifying equal treatment (e.g. a proportional reduction rule) in a treaty, gains to the “narrow but deep” approach may warrant a smaller coalition.

中文翻译：

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负外部性协议中的同一性和平等待遇

本文考察了国际环境协定中两类条款的相互作用：基于身份的最低参与条款 (MPC) 和平等待遇条款。虽然 MPC 已在多边协定的背景下得到广泛研究，但本文首次正式引入条约，规定所有参与者从无条约均衡中按等比例减少。这两项规定的存在是否有助于或阻碍大联盟的形成和效率？在平等对待和代理异质性的情况下，较小的联盟可能会比需要大联盟带来更高的福利。对一组博弈进行博弈论分析，本文给出了使这一福利结果在一次性负外部性联盟博弈中成立的一组充分条件，并举例说明了较小的协议何时可以改善和不改善一致性。此外，本文侧重于谈判规则的选择如何影响最佳签署人集。通过在条约中规定平等待遇（例如按比例减少规则），“窄而深”方法的收益可能需要较小的联盟。