The Human Development Index (HDI) is a composite statistical index developed by Pakistani economist Mahbub ul-Haq and utilized by the United Nations Development Programme (UNDP) to measure and rank countries' development beyond purely economic metrics. Its explicit purpose is to shift the focus of development economics from national income accounting to people-centered policies. The HDI assesses a country's progress across three fundamental dimensions: a long and healthy life (measured by life expectancy at birth), knowledge (assessed by mean and expected years of schooling), and a decent standard of living (indicated by Gross National Income per capita at purchasing power parity). Anchored in Amartya Sen's work on human capabilities, the HDI framework considers whether people are able to "be" and "do" desirable things in life, emphasizing freedom of choice. A higher HDI score signifies greater lifespan, education levels, and per capita income.

The HDI underwent a significant methodological update in its 2010 Human Development Report, introducing a new calculation method that uses a geometric mean of normalized indices for life expectancy, education, and income. This update also presented the Inequality-adjusted Human Development Index (IHDI), which accounts for inequalities within a country, thereby representing the "actual level of human development" as opposed to the standard HDI, which can be seen as "potential" development if no inequality existed. While comprehensive, the HDI does not incorporate certain factors like net wealth per capita or the relative quality of goods, which can sometimes lead to lower rankings for highly developed nations, including G7 members, despite their advanced economies.