The index is based on the human development approach, developed by Mahbub ul Haq, anchored in Amartya Sen's work on human capabilities, often framed in terms of whether people are able to "be" and "do" desirable things in life. Examples include – being: well fed, sheltered, healthy; doing: work, education, voting, participating in community life. The freedom of choice is central – someone choosing to be hungry (e.g. when fasting for religious reasons) is quite different from someone who is hungry because they cannot afford to buy food, or because the country is in a famine.
The index does not take into account several factors, such as the net wealth per capita or the relative quality of goods in a country. This situation tends to lower the ranking for some of the most advanced countries, such as the G7 members and others.
The origins of the HDI are found in the annual Human Development Reports produced by the Human Development Report Office of the United Nations Development Programme (UNDP). These were devised and launched by Pakistani economist Mahbub ul Haq in 1990, and had the explicit purpose "to shift the focus of development economics from national income accounting to people-centered policies". Haq believed that a simple composite measure of human development was needed to convince the public, academics, and politicians that they can and should evaluate development not only by economic advances but also improvements in human well-being.
The underlying principles behind the Human Development Index.
This methodology was used by the UNDP until their 2011 report.
The formula defining the HDI is promulgated by the United Nations Development Programme (UNDP). In general, to transform a raw variable, say , into a unit-free index between 0 and 1 (which allows different indices to be added together), the following formula is used:
The Human Development Report 2020 by the United Nations Development Programme was released on 15 December 2020, and calculates HDI values based on data collected in 2019. The list comprises countries and territories with very high human development:
The Inequality-adjusted Human Development Index (IHDI) "can be interpreted as the level of human development when inequality is accounted for. The relative difference between IHDI and HDI values is the loss due to inequality in distribution of the HDI within the country." The list comprises countries and territories with very high and high human development:
The Human Development Index has been criticized on a number of grounds, including alleged lack of consideration of technological development or contributions to the human civilization, focusing exclusively on national performance and ranking, lack of attention to development from a global perspective, measurement error of the underlying statistics, and on the UNDP's changes in formula which can lead to severe misclassification in the categorisation of "low", "medium", "high" or "very high" human development countries.
Economists Hendrik Wolff, Howard Chong and Maximilian Auffhammer discuss the HDI from the perspective of data error in the underlying health, education and income statistics used to construct the HDI. They identified three sources of data error which are due to (i) data updating, (ii) formula revisions and (iii) thresholds to classify a country's development status and conclude that 11%, 21% and 34% of all countries can be interpreted as currently misclassified in the development bins due to the three sources of data error, respectively. The authors suggest that the United Nations should discontinue the practice of classifying countries into development bins because: the cut-off values seem arbitrary, can provide incentives for strategic behavior in reporting official statistics, and have the potential to misguide politicians, investors, charity donors and the public who use the HDI at large.
In 2010, the UNDP reacted to the criticism and updated the thresholds to classify nations as low, medium, and high human development countries. In a comment to The Economist in early January 2011, the Human Development Report Office responded to a 6 January 2011 article in the magazine which discusses the Wolff et al. paper. The Human Development Report Office states that they undertook a systematic revision of the methods used for the calculation of the HDI, and that the new methodology directly addresses the critique by Wolff et al. in that it generates a system for continuously updating the human-development categories whenever formula or data revisions take place.
In 2013, Salvatore Monni and Alessandro Spaventa emphasized that in the debate of GDP versus HDI, it is often forgotten that these are both external indicators that prioritize different benchmarks upon which the quantification of societal welfare can be predicated. The larger question is whether it is possible to shift the focus of policy from a battle between competing paradigms to a mechanism for eliciting information on well-being directly from the population.
^ abNations, United (2017). "What is Human Development". UNDP. Archived from the original on 27 October 2017. Retrieved 27 October 2017. ... human development approach, developed by the economist Mahbub Ul Haq ...'
^Mean years of schooling (of adults) (years) is a calculation of the average number of years of education received by people ages 25 and older in their lifetime based on education attainment levels of the population converted into years of schooling based on theoretical duration of each level of education attended. Source: Barro, R. J.; Lee, J.-W. (2010). "A New Data Set of Educational Attainment in the World, 1950–2010". NBER Working Paper No. 15902. doi:10.3386/w15902. Archived from the original on 7 August 2011. Retrieved 29 July 2011.
^(ESYI is a calculation of the number of years a child is expected to attend school, or university, including the years spent on repetition. It is the sum of the age-specific enrollment ratios for primary, secondary, post-secondary non-tertiary and tertiary education and is calculated assuming the prevailing patterns of age-specific enrollment rates were to stay the same throughout the child's life. Expected years of schooling is capped at 18 years. (Source: UNESCO Institute for Statistics (2010). Correspondence on education indicators. March. Montreal.)