The majority of comparative metrics assessing the well-being of people in countries omit social cleavages—such as gender and ethnicity—that influence experiences of marginalization and exclusion. To identify policies and interventions that promote inclusivity and equity, the Haas Institute has developed the “Inclusiveness Index.” This new paper explains the development of the Index, which is based on factors such as outgroup violence, political representation, income inequality, and rates of incarceration. Based on these metrics, the US is ranked as having low inclusivity globally. The authors then apply the index to the US internally, noting the geographic concentration of incarceration, persistent income inequality, and discriminatory laws.