Agree to disagree? Making sense of vagueness in International Environmental Agreements
重新审视了国际环境协议中的深度-参与困境，提出协议模糊性与国家制度能力相互作用的理论框架，并基于1995-2018年五个气候相关协议的批准数据，发现模糊性通常抑制批准，而制度差异会削弱从众效应。
The prevailing literature on International Environmental Agreements (IEAs) commonly posits the existence of a Depth-Participation Dilemma (DPD), suggesting that while precise agreements with well-defined obligations promote deeper cooperation, their specificity often deters participation. This paper revisits this assumption and introduces the differing institutional capacities of the negotiating countries. It thus provides a theoretical framework for understanding the interplay between vagueness, institutional capacities, and, most importantly, the dynamics of the DPD. Our analysis suggests that the DPD is only relevant when institutional capacities are highly uneven across negotiating states, or when a significant number of participants have limited capacities. In contrast, we find that greater precision enhances participation when most negotiating countries possess moderate to high institutional capacities. To test these predictions, we analyze ratification behavior for five climate-related IEAs from 1995 to 2018, constructing a precision index. Our empirical findings reveal (i) a bandwagon effect, where countries are more likely to ratify agreements when others do, (ii) that greater institutional differences weaken this bandwagon effect, thereby reducing ratification rates, (iii) that vagueness in agreements generally undermines incentives to ratify, and (iv) that vague agreements, once ratified, are less binding and correlate with higher CO 2 emissions. This framework and evidence provide new insights into how agreement design influences participation and effectiveness in IEAs. • We examine the Depth-Participation Dilemma (DPD) in environmental agreements. • A theoretical framework with the agreements vagueness is developed. • The DPD is relevant when institutions are uneven across negotiating states. • A precision index is constructed for five climate-related agreements. • We analyze ratification behavior for these agreements from 1995 to 2018. • We find a bandwagon effect where countries ratify agreements when others do. • Greater institutional differences weaken this bandwagon effect. • This framework provides insights on the participation in environmental agreements.