In the past several years, there has been a muchdiscussed rise in strain on multilateralism, which is understood here as coordinated action among three or more states. However, there have been few efforts to quantifiably assess the state of the multilateral system. This Multilateralism Index (MI) report is the first known attempt to do so. It focuses on developments in the system over the past decade, providing a snapshot of its relative strength in 2020 compared to 2010. It seeks to answer questions including: What is the state of the multilateral system? What is working? What is not? And how has the multilateral system changed over time?

This report is based on the analysis of uniform, year-on-year quantitative data related to the functioning of the multilateral system over time. However, given that many of the most critical developments in multilateralism cannot be captured by looking at such numbers in isolation, the MI provides necessary context through qualitative analysis and complementary quantitative data sources. As the present report is only a pilot version of the MI, it provides data visualizations for most, but not all, of the individual indicators that make up the index.