The Human Development Index (HDI) is a statistical tool used to measure a countrys overall achievement in its social and economic dimensions. It was introduced by the United Nations in 1990 to emphasize that people and their capabilities should be the ultimate criteria for assessing the development of a country, not economic growth alone. The HDI is a single index measure that aims to record the three key dimensions of human development: access to knowledge, a decent standard of living, and long and healthy life. The HDI is calculated using the following indicators:

• Life expectancy at birth, which measures the health dimension of human development.
• Mean years of schooling for adults aged 25 years and more and expected years of schooling for children of school entering age, which measures the education dimension of human development.
• Gross national income (GNI) per capita, which measures the standard of living dimension of human development.

The HDI is the geometric mean of normalized indices for each of the three dimensions. The HDI can be used to question national policy choices, asking how two countries with the same level of GNI per capita can end up with different human development outcomes. The HDI simplifies and captures only part of what human development entails. It does not reflect on inequalities, poverty, human security, empowerment, etc. .