Inequality-adjusted Human Development Index

Also called: IHDI · Topic: Measuring Development: Income, HDI and Sustainability · NCERT: Beyond NCERT

Meaning

The Inequality-adjusted Human Development Index (IHDI) is the HDI after each of its three parts (health, education and income) is cut down by how unequally that part is shared among the people of a country. The HDI shows the "potential" level of human development, meaning what people would get if everything were shared equally. The IHDI shows the level people actually get.

• IHDI = [(1 − A_health)·I_health × (1 − A_edu)·I_edu × (1 − A_income)·I_income]^(1/3)
• Loss due to inequality (%) = (1 − IHDI ÷ HDI) × 100

A national average like the HDI can look good even when gains go to only a few people. The IHDI shows how much human development a country loses because its gains are not shared fairly. UNDP brought it in with the 2010 Human Development Report.

Explanation

Starting point: the HDI

• HDI (Human Development Index) is the geometric mean of three dimension indices: health, education and income (standard of living).

• Formula: HDI = (I_health × I_education × I_income)^(1/3).

• The HDI is a national average, so it says nothing about how the gains are shared between people.

• The IHDI fixes this gap. It uses the same three dimensions but adjusts each one for inequality.

The Atkinson inequality measure (A)

• Atkinson inequality measure measures how far the geometric mean of a distribution falls below its arithmetic mean (the simple average).

• A = 1 − (geometric mean ÷ arithmetic mean)

• When everyone has the same amount, both means are equal. Then A = 0, and there is no discount.

• The more unequal the spread, the further the geometric mean falls below the simple average. So A rises.
• Worked example: two people earn 1 and 4.
• Arithmetic mean = (1 + 4) ÷ 2 = 2.5
• Geometric mean = √(1 × 4) = 2
• A = 1 − 2/2.5 = 0.20, a 20% inequality discount

How the IHDI is built

• Step 1: Find A separately for health, education and income.
• Step 2: Multiply each dimension index by (1 − A) for that dimension.
• Step 3: Take the geometric mean of the three adjusted indices. The result is the IHDI.
• Simple check: suppose all three dimensions have A = 0.20.
• Each index is multiplied by 0.80, so the IHDI = 0.80 × HDI.
• Loss due to inequality = (1 − 0.80) × 100 = 20%.

What makes the IHDI rise or fall

• IHDI ≤ HDI, always. The two are equal only under perfect equality.
• The gap widens when:
• income is concentrated among a few households;
• life expectancy differs sharply between rich and poor, or between regions;

• schooling is spread unevenly, for example between girls and boys or between rural and urban areas.

• The gap narrows when:

• basic health, schooling and jobs reach the bottom groups. Their gains lift the geometric mean more than the same gains at the top would.

• Key point: a country can raise its HDI and still see its IHDI lag behind if the gains go mostly to people who are already better off.

In India

• Who measures it: UNDP (United Nations Development Programme) publishes it in the annual Human Development Report (HDR). HDR 2025 is titled "A Matter of Choice: People and Possibilities in the Age of AI" [1].
• India's HDI: 0.685 (2023 data, HDR 2025), up from 0.676 (2022). India ranks 130 of 193 and is in the "medium human development" group [1].
• India's IHDI: about 0.47. The loss due to inequality is 30.7% (HDR 2025) [1].

• Check: 0.685 × (1 − 0.307) ≈ 0.475, which matches the IHDI of ~0.47 [1].

• How India compares: its loss of 30.7% is one of the highest in South Asia [1].

• Where the loss comes from (HDR 2025):
• Inequality in health and education has come down [1].

• Income and gender gaps are still large [1].

• The gender gap in numbers:

• Female LFPR (labour force participation rate, meaning the share of women aged 15+ who are working or looking for work) rose from 37.0% (2022–23) to 41.7% (2023–24) (PLFS, the Periodic Labour Force Survey) [3].

• Even so, UNDP says female LFPR and political representation are where India lags most [1].

• The big picture: India's HDI has risen by over 53% since 1990, faster than the world and South Asian averages [1]. But the 30.7% loss shows that these gains are not evenly shared.

Don't confuse with

• HDI: a plain national average of health, education and income. It is the "potential" level. The IHDI is the level people actually get after the inequality discount, so IHDI ≤ HDI.
• Gender Development Index (GDI): GDI = female HDI ÷ male HDI, and 1 = parity. It measures only the gap between women and men. The IHDI measures inequality across all people, not just by gender.
• Gender Inequality Index (GII): its scale runs from 0 = equality to 1, and higher = worse. It uses its own 5 indicators (MMR, adolescent birth rate, parliamentary seats, secondary education, LFPR), not the HDI's three dimension indices.
• Multidimensional Poverty Index (MPI) (2010, UNDP with OPHI, Oxford): it counts overlapping deprivations in poor households. It is a poverty measure, not an inequality discount on the HDI.

Prelims Hooks

• IHDI was introduced by UNDP in 2010. It discounts each HDI dimension (health, education, income) by its Atkinson inequality measure.
• Atkinson measure: A = 1 − (geometric mean ÷ arithmetic mean). A = 0 means perfect equality.
• Loss due to inequality (%) = (1 − IHDI/HDI) × 100. India's loss is 30.7% (HDR 2025), one of the highest in South Asia [1].
• Trap: the IHDI can never be higher than the HDI. It equals the HDI only under perfect equality.
• India, HDR 2025: HDI 0.685 (2023 data), IHDI ~0.47, rank 130/193, medium human development [1].
• Trap: HDI = potential human development, IHDI = actual human development. Do not swap them.

Mains Points

• Growth without fair sharing (GS-III):
• India's HDI has risen by more than 53% since 1990 [1], but a 30.7% loss due to inequality [1] shows that the gains are unevenly shared.
• Health and education inequality has fallen, but income and gender gaps remain large [1]. Female LFPR was only 41.7% in 2023–24 [3].

• Policy link: focus on quality of learning (not just enrolment), jobs for women and targeted welfare. These lift the bottom groups, which narrows the HDI–IHDI gap fastest.

• Better measurement for better policy (GS-II/III):

• A single HDI rank hides who is left behind. Reading the IHDI alongside the GII, PHDI and MPI gives a truer picture.

• Women's representation may improve under the Constitution (106th Amendment) Act, 2023 (Nari Shakti Vandan Adhiniyam), which reserves one-third of seats in the Lok Sabha and State Assemblies for women [2]. UNDP says this "offers promise" [1]. Narrowing gender gaps would help reduce India's inequality loss.

• Limits of the IHDI:

• It adjusts only the same three HDI dimensions. It still leaves out freedom, rights and the rule of law (NCERT's liberty critique) and damage to the environment (covered by the PHDI).
• So a lower inequality loss does not by itself mean fuller development.

Related concepts

• Gender Development Index
• Gender Inequality Index
• Liberty indicators
• Physical Quality of Life Index

Read more

• The HDR family of indices and the liberty critique