Initiated in 2002, the International Environmental Agreements Data Base (IEADB) catalogs the texts, memberships, and design features of over 3,000 multilateral and bilateral environmental agreements. Using IEADB data, we create a comprehensive review of the evolution of international environmental law, including how the number, subjects, and state memberships in IEAs have changed over time. By providing IEA texts, the IEADB helps scholars identify and systematically code IEA design features. We review scholarship derived from the IEADB on international environmental governance, including insights into IEA membership, formation, and design as well as the deeper structure of international environmental law. We note the IEADB’s value as a teaching tool to promote undergraduate and graduate teaching and research. The IEADB’s structure and content opens up both broad research realms and specific research questions, and facilitates the ability of scholars to use the IEADB to answer those questions of greatest interest to them.

To accurately assess the relative effectiveness of international environmental agreements requires that we pay greater attention to how problem structures influence both institutional design and the outcomes we use to evaluate institutional effects. Analyzing multiple agreements allows us to move beyond claims that an agreement was influential to claims regarding which variables explain that influence, to examine how institutional influence depends on other factors and to evaluate an agreement's effectiveness relative to other agreements and non-institutional influences. Accounting for problem structure is crucial to such endeavors because problem structure variables may be alternatives to or interact with institutional variables and because institutional design is endogenous to the problem structure-outcome relationship. The shortcomings related to incorporating problem structure in extant effectiveness research can be overcome through four strategies: carefully describing analytically useful variation in problem structure, selecting cases to limit variation in problem structure, evaluating problem structure variables and their influence on design and behavior, and evaluating effectiveness in terms appropriate to the problem structure.

Quantitative analysis of environmental regime effects can complement qualitative analyses by allowing investigation of variation in the effects of different regimes as well as the causes and conditions that explain that variation. Such analysis involves developing metrics that allow comparison of the influence of disparate regimes, models that distinguish regime influence from other explanatory factors, and data sets of independent and dependent variables of sufficient quality to support quantitative analysis. The many theoretical, methodological, and empirical obstacles to undertaking quantitative research on regime effectiveness are daunting but surmountable. By using data regarding component parts of regimes (“subregimes”) broken down to the country and year level, quantitative techniques offer promise in identifying which regimes induce greater behavioral change and greater “effort” and, more importantly, what characteristics of those regimes and the context in which they operate explain their greater success.