The Social Institutions and Gender Index (SIGI) is a new composite measure of gender equality, based on the OECD’s Gender, Institutions and Development Database. It complements and improves existing measures in several ways. While conventional indicators of gender equality capture inequality outcomes, the SIGI focuses on the root causes behind these inequalities.

The Social Institutions and Gender Index has been constructed by the OECD Development Centre, in collaboration with a research team from Göttingen University under the leadership of Prof. Stephan Klasen. Valuable input and validation of the team's findings were equally provided by Geske Dijkstra and her team at Erasmus University Rotterdam. The index is based on 124 detailed country notes which provided the basis of the social institutions variables.