The Human Development Index and its family: HDI, IHDI, GDI, GII, MPI and the SDGs

For decades, development was measured by income per head. In the 1980s Amartya Sen argued that what matters is what people are able to do and to be, their capabilities: to live long, to be educated, to take part in the life of their community. Income is a means to these ends, and countries with the same income can differ widely in life expectancy and schooling. Mahbub ul Haq, working with Sen and others, put this into practice in the first Human Development Report of the United Nations Development Programme in 1990, and the Human Development Index was the headline number: simple enough to be put beside GDP per head in a table.

The index has been revised. The 1990 version used adult literacy, life expectancy and income; later editions added schooling and, in the 2010 Report (the twentieth anniversary), changed to mean and expected years of schooling, gross national income per head in place of GDP, and a geometric mean in place of an arithmetic one. The 2010 Report also introduced the inequality-adjusted HDI, the Gender Inequality Index and the global Multidimensional Poverty Index. The current method is the one in UNDP’s technical notes for the 2025 Report, which is used throughout this lesson. Some exam questions still use older descriptions: read the options carefully.

Step 1: turn each indicator into an index between 0 and 1, using fixed minimum and maximum values called goalposts: (actual − minimum)/(maximum − minimum). The goalposts act, in UNDP’s words, as the “natural zeros” and the “aspirational targets”.

Three details matter. Education takes the arithmetic mean of the two schooling indices. Income is in logarithms: Index = (ln GNI − ln 100)/(ln 75,000 − ln 100). This is because each extra dollar adds less to human capabilities in a rich country than in a poor one; doubling income adds the same amount to the index (ln 2/ln 750 = 0.105) wherever on the scale a country starts, so a poor country gains far more from an extra $1,000 than a rich one. And the ceiling: above $75,000 income adds nothing to the HDI (nine economies exceeded it in 2023, among them Norway, Switzerland and Singapore).

Step 2: take the geometric mean of the three indices.

Why a geometric mean? The arithmetic mean treats the dimensions as perfect substitutes: a country could make up for illiteracy with high income. The geometric mean punishes imbalance. With indices of 0.9, 0.9 and 0.1, the arithmetic mean is 0.63 but the geometric mean is 0.43. The same logic says the HDI rises faster when the weakest dimension improves; for a given total improvement, raising the lowest index adds most. (UGC NET asks in several forms whether the HDI is arithmetic or geometric; the answer for the current HDI is geometric, and the pre-2010 HDI used the arithmetic mean.)

Categories. UNDP has used fixed cut-offs since 2014: very high human development 0.800 and above; high 0.700–0.799; medium 0.550–0.699; low below 0.550.

Choose a country to load its 2023 values from the Human Development Report 2025, or set the four indicators yourself. The bars show the three dimension indices; the HDI is their geometric mean, and the arithmetic mean is shown so you can see how much the choice of mean matters. Try raising only income in Niger, and then only schooling: which moves the HDI more? The last slider applies a loss to inequality (Section 5) to give an IHDI.

The table gives the HDI and components for thirteen countries in 2023, from the UNDP data centre. India’s HDI is 0.685, ranked 130 of 193 and tied with Bangladesh: life expectancy is 72.0 years, expected years of schooling 12.95, mean years of schooling 6.88 and GNI per head $9,047. The weak spot, as the indices show, is education: the mean years of schooling (6.9) is less than half of the 15-year goalpost, so the education index (0.589) is the lowest of the three, and because of the geometric mean it pulls the HDI below the simple average of 0.690.

Over time. The HDI has risen almost everywhere. India: 0.446 in 1990, 0.501 in 2000, 0.590 in 2010 and 0.685 in 2023. Bangladesh rose from 0.397 to 0.685 and now equals India; China from 0.491 to 0.797; Pakistan from 0.396 to 0.544; Sri Lanka, which started much higher, from 0.638 to 0.776. Because income enters in logarithms and the other indices have a ceiling, the HDI rises more slowly as a country gets closer to the top.

Inequality-adjusted HDI (IHDI). Each dimension’s average hides a distribution. The IHDI discounts each dimension index by an Atkinson inequality measure, A = 1 − g/μ, where g is the geometric mean and μ the arithmetic mean of the distribution (the Atkinson aversion parameter is set to 1), and then takes the geometric mean: IHDI = [(1 − A_health)(1 − A_education)(1 − A_income)]^1/3 × HDI. The loss to inequality is 1 − IHDI/HDI. UNDP’s example is Nepal: HDI 0.622, IHDI 0.437, a loss of 29.7%. India’s IHDI is 0.475, a loss of 30.7%; Norway’s loss is 6.3% and Niger’s 36.8%. The IHDI is based on the work of Foster, López-Calva and Székely (2005) and on Atkinson (1970).

Gender Development Index (GDI). The ratio of the female HDI to the male HDI, computed with the same goalposts except that female life expectancy runs from 22.5 to 87.5 and male from 17.5 to 82.5 (to allow for women’s five-year biological advantage). A value of 1 means equal achievement; India’s is 0.874, because women’s estimated earned income is far below men’s. It measures the gap in achievement, not whether women have been discriminated against as such.

Gender Inequality Index (GII). A measure of loss, from 0 (equality) to 1, in three dimensions: reproductive health (maternal mortality ratio and adolescent birth rate), empowerment (the shares of parliamentary seats held by each sex and of each sex with at least some secondary education) and the labour market (participation rate). India’s 2023 value is 0.403 and rank 102 of the countries ranked.

Planetary pressures-adjusted HDI (PHDI). HDI × (1 − index of planetary pressures), where the pressures are carbon dioxide emissions and the material footprint per head: a country that gets its HDI through heavy emissions is penalised. The idea is the intergenerational counterpart of the IHDI.

Human Poverty Index (HPI). The HPI measured deprivation, not achievement. HPI-1, introduced in the 1997 Report for developing countries, combined the probability at birth of not surviving to 40, adult illiteracy and an index of deprivation in access to services (safe water, health services, child nutrition). HPI-2, in the 1998 Report, was for industrialised countries: the probability of not surviving to 60, adult illiteracy, the share of people below half the median disposable income and the long-term unemployment rate, the last two being the social-exclusion dimension. (UGC NET asks which dimension HPI-2 includes: social inclusion.) The difference from the HDI, as GATE 2025 asks, is deprivation against achievement. The 2010 Report replaced the HPI with the MPI.

Multidimensional Poverty Index (MPI). Developed by Sabina Alkire and James Foster (2011) and used in the global MPI of UNDP and the Oxford Poverty and Human Development Initiative (OPHI). It looks at households: ten indicators in three equally weighted dimensions. Health (nutrition and child mortality, weight 1/6 each), education (years of schooling and school attendance, 1/6 each) and standard of living (cooking fuel, sanitation, drinking water, electricity, housing and assets, 1/18 each). A person is poor if the household is deprived in at least one third of the weighted indicators. The MPI is H × A, the headcount ratio (the share of people who are poor) times the intensity (the average share of weighted deprivations among the poor). India’s own national MPI by NITI Aayog uses twelve indicators, adding maternal health and bank accounts to the ten; its progress review reported that the headcount fell from 24.85% in 2015–16 to 14.96% in 2019–21, a fall of about 13.5 crore people. Income poverty lines and the committees that set them are on the poverty measures and poverty committees pages.

Physical Quality of Life Index (PQLI). Morris D. Morris (1979) proposed an index of three components: infant mortality, life expectancy at age one and literacy, each scaled from 0 to 100 and averaged. It was an early non-income measure, and a standard match with HDI (UNDP, Haq) and the capability approach (Sen) in exam questions: PQLI–Morris, HDI–Haq, capability approach–Sen, MPI–Alkire and Foster.

Global Hunger Index. Four indicators: undernourishment (weight 1/3), child mortality (1/3), child stunting (1/6) and child wasting (1/6). (UGC NET December 2023 asks the weights under the name World Hunger Index.)

The Millennium Development Goals followed the UN Millennium Declaration of September 2000 (General Assembly resolution 55/2): eight goals with targets for 2015, measured from 1990: eradicate extreme poverty and hunger; achieve universal primary education; promote gender equality and empower women; reduce child mortality; improve maternal health; combat HIV/AIDS, malaria and other diseases; ensure environmental sustainability; and develop a global partnership for development. (UGC NET asks the target year, which was 2015, not 2016.)

The Sustainable Development Goals, in the 2030 Agenda adopted on 25 September 2015 (resolution 70/1), have 17 goals and 169 targets, to be reached by 2030 and applying to all countries, rich and poor. Their reach goes beyond the MDGs to climate, inequality, cities, consumption and institutions. The goals most often asked in exams are below.

Questions on the HDI and its components, the indices that adjust it, the poverty and hunger indices, and the MDGs and SDGs. Questions on the demographic measures that feed these indices (maternal mortality, fertility) are in Lesson 9.