Do Gender Development Index and Inequality-adjusted HDI go together across countries?

Across 165 countries the link before adjusting for anything is r = +0.67, on a scale from -1 (opposite) to +1 (in step). A version that uses only each country's rank gives +0.67.

Does the link hold within countries over time, not just across countries?

Comparing each country only with itself across 2010-2023, and setting aside what happened worldwide in each year, the link is +0.210 (163 countries, 2,064 country-years). Using year-to-year changes, it is -0.031.

Does Gender Development Index cause Inequality-adjusted HDI?

This analysis cannot answer that. It shows only that the two go together. A link between two country measures, adjusted or not, does not show that either one changes the other. Country figures also say nothing about individual people.

Gender Development Index vs. Inequality-adjusted HDI

Fades after adjusting for income

Across 165 countries, Gender Development Index and Inequality-adjusted HDI rise and fall together at r = +0.67 (on a scale from −1 to +1, where 0 means no link). Comparing only countries with similar income (GDP per person) shrinks it to +0.26, which could easily be chance (q = 0.23, allowing for the many pairs tested, and allowing for countries in the same region being alike). So the first figure mostly shows richer countries differing from poorer ones, not a link between these two things. Caution: direction is not consistent across regions. Gender Development Index and Inequality-adjusted HDI share a building block (undp eys, undp mys, wdi gni per capita, wdi life expectancy), so part of this link is mechanical: they are bound to match to some degree.

Comparing countries across the middle half of gender development index, 0.927 to 0.994 ratio of women's HDI to men's, inequality-adjusted hdi is better by 0.145 points at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 0.0268 points.

Link before adjusting (r)+0.671p = 6.6e-23 · 165 countries

After adjusting for national income+0.263p = 0.001 · likely range [+0.11, +0.40]

p, allowing for regions0.075standard error 0.122 · 7 regions

Check for luck (q)0.228across 12,497 pairs

How to read these.r runs from −1 (one goes up as the other goes down) to +1 (they rise together), and 0 means no link. Adjusting for national income means comparing countries with the same GDP per person, so differences in wealth can’t explain the link. Income is used in percentage terms, since an extra $1,000 means more to a poor country than to a rich one. p is how likely a link this strong would be if there were really none. Below 0.05 means it is unlikely to be chance. Very small values are written in short form: 1.1e-32 means a decimal point followed by 31 zeros and then 11, so very close to zero. The likely range is where the true figure probably lies, and a range that crosses zero means the link could easily be chance. Countries in the same region tend to resemble each other, so the third figure allows for that, which gives a fairer p. The standard error is the typical size of the error in r. Finally, testing this many pairs means some will look strong by luck alone. A q below 0.05 means this link is unlikely to be one of those.

Gender Development Index · ratio of women's HDI to men'slink with income +0.65 · high

Inequality-adjusted HDI · index, 0 to 1link with income +0.94 · proxy

Both of these rise and fall closely with national income, so a strong link between them before adjusting was close to certain. Read the adjusted figure, not the first one.

“Link with income” is how closely each measure tracks GDP per person across countries, from −1 to +1.

Built from the same numbers. Gender Development Index and Inequality-adjusted HDI share a building block (undp eys, undp mys, wdi gni per capita, wdi life expectancy), so part of this link is mechanical: they are bound to match to some degree.

Every country as a dot

best-fit line line after adjusting

Four ways to measure the link

Method	r	p	Countries
Standard (Pearson), not adjusted	+0.671	6.6e-23	165
By rank (Spearman), not adjusted	+0.670	8.3e-23	165
Standard (Pearson), adjusted for national income	+0.263	0.001	165
By rank (Spearman), adjusted for national income	+0.162	0.038	165

The rank version uses only each country’s place in line, from lowest to highest, so a few extreme countries count for less. The adjusted and unadjusted versions use the same 165 countries: those that report both measures and GDP per person. So the gap between them comes from the adjustment, not from a change in which countries are counted. Drop in the size of r after adjusting: +0.407 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from +0.238 (without DJI) to +0.299 (without AFG). The bar above shows that range on a scale from −1 to +1, with the solid line at the full result. The single country that moves r most: AFG (+0.035).

Fragile: this link may not hold up.

direction is not consistent across regions

Within each region

Countries are not separate, unrelated cases, and neighbors share a lot. A link that holds inside each region is far more believable than one that shows up only when comparing regions.

	n	r
East Asia & Pacific	29	+0.29
Europe & Central Asia	46	+0.07
Latin America & Caribbean	22	-0.09
Middle East, North Africa, Afghanistan & Pakistan	16	+0.41
Sub-Saharan Africa	44	+0.50

By income third

If the link shows up only in the richest third of countries, it is a feature of rich countries, not a general pattern.

	n	r
Poorest third	55	+0.51
Middle third	55	+0.05
Richest third	55	-0.09

By largest religious group

Countries grouped by a label they share, such as main religion, rather than by a number. Groups of fewer than twelve countries are not shown. These groups differ in income, region and history all at once. So a gap between them is a place to start asking questions, not an answer.

	n	r
Christians	99	+0.12
Muslims	41	+0.21

By last european coloniser

	n	r
France	23	+0.43
Never a European colony	18	+0.32
Spain	18	+0.20
United Kingdom	51	+0.15

Without outliers (countries far outside the middle half of countries on either measure, by more than one and a half times the width of that middle half): r = +0.267 after dropping 8 countries.

Two series, one country

Both measures over the years for one country you pick. The two charts are stacked so they share only the years along the bottom.

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Over time, within countries

Everything above compares countries with each other at one moment. This section compares each country only with itself over 14years. So a link here can’t come from anything about a country that stays the same, such as its history, geography, institutions or culture.

The link shows up within countries over time (r = +0.210) but mostly disappears in year-to-year changes (r = -0.031). That points to slow trends particular to each country, not the two measures moving together from year to year.

Across countries (adjusted)+0.263for comparison

Within countries+0.393each country vs itself

…and vs the same year elsewhere+0.210q = 0.019 · 163 countries

Year-on-year changes-0.031q = 0.729

Read with care.

Almost all of this indicator's variation is between countries, not within them, so the within-country estimate rests on a small part of the data.

2,064 country-years (one country in one year), 163 countries, 2010–2023, about 13 years each on average. Share of the variation that happens within countries over time: 4% for Gender Development Index, 1% for Inequality-adjusted HDI. The margins of error allow for each country appearing many times, and for each year’s value being close to the year before.

Year-to-year changes are a cautious test, not a final answer. Looking only at changes from one year to the next removes each country’s own trends. But it also makes measurement mistakes louder, which pulls the results toward zero. A near-zero result here is weak evidence of no link, not proof.

With one measure years behind the other

Same year (lag 0): +0.210. A peak away from zero does not show which comes first. These series change slowly — this year’s value is close to last year’s. That makes the curve smooth and nearly symmetric, whatever produced the data. Even a sharp peak at one lag (a gap of some years) would not prove that one measure changes the other.

The data

	ratio of women's HDI to men's	index, 0 to 1	Years
Ukraine UKR	1.04	0.715	2023
Barbados BRB	1.03	0.62	2023
Mongolia MNG	1.03	0.647	2023
Moldova MDA	1.03	0.719	2023
Latvia LVA	1.03	0.812	2023
Dominican Republic DOM	1.02	0.634	2023
Russian Federation RUS	1.02	0.758	2023
Estonia EST	1.02	0.841	2023
Lithuania LTU	1.02	0.812	2023
Uruguay URY	1.02	0.747	2023
St. Lucia LCA	1.02	0.523	2023
Bahamas, The BHS	1.01	0.67	2023
Panama PAN	1.01	0.664	2023
Jamaica JAM	1.01	0.59	2023
Poland POL	1.01	0.817	2023

United Nations Development Programme, Human Development Report 2025
United Nations Development Programme, Human Development Report 2025

Sources

Gender Development Index

United Nations Development Programme, Human Development Report Office · via Our World in Data · CC BY 3.0 IGO · updated annual

The HDI worked out for women divided by the HDI worked out for men. It is above 1 where women score higher, as they do in several countries on health. So no "better" direction is set: equality is the aim, and equality is the middle of the scale, not one end of it.

Inequality-adjusted HDI

Inequality-adjusted Human Development Index

United Nations Development Programme, Human Development Report Office · via Our World in Data · CC BY 3.0 IGO · updated annual · comparable from 2010 only

The HDI marked down for how unequally each of its three parts is spread within the country. The gap between this and the HDI is what inequality costs, and that is the number worth reading. The level itself is the HDI again, with its parts flagged the same way.

How this was computed

Data used: most recent value in 2010-2025; values come from 2015–2023. To adjust for income, each measure is first predicted from GDP per person (in percentage terms, on a log scale) with a straight-line fit. Only what is left over is then compared. This is called a partial correlation. The line is drawn the standard way (ordinary least squares), which picks the line that comes closest to all the countries at once. The error margins allow for countries in the same region resembling each other, using 7 World Bank regions. The q-value corrects for testing all 12,497 pairs at once, using the Benjamini–Hochberg method. Underlying data last updated DYB 2024. How the country data works · explore Gender Development Index and Inequality-adjusted HDI

This page shows that two measures go together. It does not show that Gender Development Index changes Inequality-adjusted HDI, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.