In terms of life expectancy, the GDI assumes that women will live an average of five years longer than men.
[4] The GEM was designed to measure "whether women and men are able to actively participate in economic and political life and take part in decision-making".
[8] The GEM is thought to be a valuable policy instrument because it allows certain dimensions that were previously difficult to compare between countries to come into international comparison.
It is designed to facilitate international comparisons by ranking countries based on three dimensions of gender inequity indicators: education, economic participation and empowerment.
The index is based on the level of female disadvantage (so it is not strictly a measure of equality), and is intended to allow comparative comparison of gender gap across different countries and years.
The report examines four critical areas of inequality between men and women in approximately 130 economies around the globe, focusing on economic participation and opportunity, educational attainment, political empowerment and health and survival statistics.
[5] Social Institutions and Gender Index (SIGI) is a composite indicator of gender equality that solely focuses on social institutions that affect the equality between men and women, as well as on the four dimensions of family code, physical integrity, ownership rights and civil liberties.
It was introduced in 2007 by the OECD Development Centre to address the perceived inadequacies of the GDI, GEM, GEI, and Global Gender Gap Index.