Across 167 countries, Gender Development Index and Pupil-teacher ratio rise and fall together at r = -0.63 (on a scale from −1 to +1, where 0 means no link). Comparing only countries with similar income (GDP per person) shrinks it to -0.28 (q = 0.035, allowing for the many pairs tested). Much of the first figure is that both measures rise with national income, but a weak negative link remains.
Comparing countries across the middle half of gender development index, 0.932 to 0.995 ratio of women's HDI to men's, pupil-teacher ratio is better by 8.48 pupils per teacher at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 2.99 pupils per teacher.
Link before adjusting (r)-0.632p = 4.9e-20 · 167 countries
After adjusting for national income-0.284p = 0.000 · likely range [-0.42, -0.14]
p, allowing for regions0.003standard error 0.058 · 7 regions
Check for luck (q)0.035across 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
Pupil-teacher ratio · pupils per teacherlink with income -0.83 · 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.
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
-0.632
4.9e-20
167
By rank (Spearman), not adjusted
-0.623
2.3e-19
167
Standard (Pearson), adjusted for national income
-0.284
0.000
167
By rank (Spearman), adjusted for national income
-0.213
0.006
167
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 167 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: +0.348 (a minus sign means it grew).
How solid is it?
Leaving out one country at a time, r ranges from -0.306 (without NPL) to -0.255 (without TCD). 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: TCD (+0.030).
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
27
-0.09
Europe & Central Asia
47
-0.12
Latin America & Caribbean
25
-0.20
Middle East, North Africa, Afghanistan & Pakistan
19
-0.68
Sub-Saharan Africa
42
-0.21
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
56
-0.29
Middle third
55
-0.14
Richest third
56
-0.01
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
-0.30
Muslims
43
-0.46
By last european coloniser
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
France
22
-0.37
Never a European colony
20
-0.31
Spain
18
-0.01
United Kingdom
53
-0.26
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 = -0.245 after dropping 11 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 30years. 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 = -0.143) but mostly disappears in year-to-year changes (r = -0.018). That points to slow trends particular to each country, not the two measures moving together from year to year.
Across countries (adjusted)-0.284for comparison
Within countries-0.448each country vs itself
…and vs the same year elsewhere-0.143q = 0.039 · 163 countries
Year-on-year changes-0.018q = 0.816
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.
Much of the within-country association disappears once shared global year effects are removed, which points to a common worldwide trend rather than a country-level relationship.
2,729 country-years (one country in one year), 163 countries, 1990–2019, about 17 years each on average. Share of the variation that happens within countries over time: 10% for Gender Development Index, 7% for Pupil-teacher ratio. 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): -0.143. 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
pupils per teacher
Years
Ukraine UKR
1.04
13
2023, 2018
Qatar QAT
1.04
12.2
2023, 2018
Barbados BRB
1.03
14
2023, 2018
Antigua and Barbuda ATG
1.03
12.4
2023, 2018
Mongolia MNG
1.03
30.4
2023, 2018
Moldova MDA
1.03
17.9
2023, 2018
Latvia LVA
1.03
11.5
2023, 2017
Dominican Republic DOM
1.02
18.9
2023, 2018
Russian Federation RUS
1.02
21.3
2023, 2017
Estonia EST
1.02
11.3
2023, 2017
Lithuania LTU
1.02
13.5
2023, 2017
Uruguay URY
1.02
11
2023, 2017
St. Lucia LCA
1.02
14.7
2023, 2018
Bahamas, The BHS
1.01
19.4
2023, 2018
Panama PAN
1.01
22
2023, 2017
United Nations Development Programme, Human Development Report 2025 World Bank, World Development Indicators
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.
UNESCO Institute for Statistics · CC BY 4.0 · updated quarterly
The World Bank's copy stops at 2019.
How this was computed
Data used: most recent value in 2010-2025; values come from 2010–2023. 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 Pupil-teacher ratio
This page shows that two measures go together. It does not show that Gender Development Index changes Pupil-teacher ratio, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.
More links with Gender Development Index or Pupil-teacher ratio