Over the past decade, an increasingly sophisticated literature has sought to capture the nature, sources, and consequences of a novel empirical phenomenon in world politics: the growing complexity of global governance. However, this literature has paid only limited attention to questions of measurement, which is a prerequisite for a more comprehensive understanding of global governance complexity across space and time. In taking a first step in this direction, we make two contributions in the article. First, we propose new quantitative measures that gauge the extent of complexity in global governance, which we conceptualize as the degree to which global governance institutions overlap. Dyadic, weighted, directed-dyadic, and monadic measures enable a multifaceted understanding of this important development in world politics. Second, we illustrate these measures by applying them to an updated version of the most comprehensive data set on the design of intergovernmental organizations (IGOs): the Measure of International Authority (MIA). This allows us to identify cross-sectional and temporal patterns in the extent to which important IGOs, which tend to form the core of sprawling regime complexes in many issue areas, overlap. We conclude by outlining notable implications for, and potential applications of, our measures for research on institutional design and evolution, legitimacy, and legitimation, as well as effectiveness and performance. This discussion underscores the utility of the proposed measures, as both dependent and independent variables, to researchers examining the sources and consequences of institutional overlap in global governance and beyond.

在过去的十年中，越来越复杂的文献试图捕捉世界政治中一种新的经验现象的性质，来源和后果：全球治理的日趋复杂。但是，该文献只对度量问题给予了有限的关注，这是更全面地理解跨时空的全球治理复杂性的前提。在朝这个方向迈出第一步时，我们在本文中做出了两个贡献。首先，我们提出了新的量化指标来衡量全球治理的复杂程度，我们将其概念化为全球治理机构重叠的程度。二元，加权，有向二元和单子度量使人们对世界政治的这一重要发展有了多方面的了解。第二，国际权威机构（MIA）的措施。这使我们能够确定重要的政府间组织在许多问题领域往往形成庞大的政权复杂结构的核心的重叠程度，从而确定横断面和时间上的格局。最后，我们概述了有关机构设计和发展，合法性和合法性以及有效性和绩效的研究措施的显着含义和潜在应用。此次讨论强调了拟议措施作为因变量和自变量的效用对研究全球治理及其他方面机构重叠的根源和后果的研究人员。