placestats

Pupil-teacher ratio vs. Undernourishment

Fades after adjusting for income

Across 151 countries, Pupil-teacher ratio and Undernourishment rise and fall together at r = +0.68 (on a scale from −1 to +1, where 0 means no link). Comparing only countries with similar income (GDP per person) shrinks it to +0.22, which could easily be chance (q = 0.27, 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.

Comparing countries across the middle half of undernourishment, 2.5% to 13% of population, pupil-teacher ratio is worse by 10.3 pupils per teacher at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 2.96 pupils per teacher.

Link before adjusting (r)+0.684p = 3.4e-22 · 151 countries
After adjusting for national income+0.224p = 0.006 · likely range [+0.07, +0.37]
p, allowing for regions0.076standard error 0.105 · 7 regions
Check for luck (q)0.272across 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.

Pupil-teacher ratio · pupils per teacherlink with income -0.83 · proxy
Undernourishment · % of populationlink 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

Pupil-teacher ratio · pupils per teacher →Undernourishment · % of population →8.383.42.5%39.5%Afghanistan: 48.8 pupils per teacher, 28.1% of populationAngola: 50 pupils per teacher, 22.5% of populationAlbania: 17.6 pupils per teacher, 5.4% of populationUnited Arab Emirates: 24.5 pupils per teacher, 2.5% of populationArmenia: 15.4 pupils per teacher, 2.5% of populationAustria: 10 pupils per teacher, 2.5% of populationAzerbaijan: 15.4 pupils per teacher, 2.5% of populationBelgium: 11.3 pupils per teacher, 2.5% of populationBenin: 39.2 pupils per teacher, 14.3% of populationBurkina Faso: 39.7 pupils per teacher, 13.1% of populationBangladesh: 30.1 pupils per teacher, 10.4% of populationBulgaria: 15.2 pupils per teacher, 2.5% of populationBosnia and Herzegovina: 16.9 pupils per teacher, 2.5% of populationBelarus: 19.2 pupils per teacher, 2.5% of populationBelize: 19.8 pupils per teacher, 7% of populationBolivia: 17.8 pupils per teacher, 21.8% of populationBrazil: 20.2 pupils per teacher, 2.5% of populationBarbados: 14 pupils per teacher, 4.4% of populationBotswana: 23.7 pupils per teacher, 24% of populationCentral African Republic: 83.4 pupils per teacher, 29.8% of populationSwitzerland: 9.93 pupils per teacher, 2.5% of populationChile: 17.8 pupils per teacher, 2.5% of populationChina: 16.4 pupils per teacher, 2.5% of populationCote d'Ivoire: 41.8 pupils per teacher, 11.1% of populationCameroon: 44.8 pupils per teacher, 4.8% of populationCongo, Dem. Rep.: 33.2 pupils per teacher, 38.5% of populationCongo, Rep.: 44.4 pupils per teacher, 26.4% of populationColombia: 23.3 pupils per teacher, 3.9% of populationComoros: 28.1 pupils per teacher, 15.4% of populationCabo Verde: 21.1 pupils per teacher, 13.5% of populationCosta Rica: 12.2 pupils per teacher, 2.5% of populationCyprus: 12 pupils per teacher, 2.5% of populationCzechia: 18.9 pupils per teacher, 2.5% of populationGermany: 12.3 pupils per teacher, 2.5% of populationDjibouti: 29.4 pupils per teacher, 12.9% of populationDominica: 13.1 pupils per teacher, 3.6% of populationDenmark: 10.7 pupils per teacher, 2.5% of populationDominican Republic: 18.9 pupils per teacher, 3.6% of populationAlgeria: 24.3 pupils per teacher, 2.5% of populationEcuador: 24.3 pupils per teacher, 12.1% of populationEgypt, Arab Rep.: 23.7 pupils per teacher, 9.4% of populationSpain: 13.1 pupils per teacher, 2.5% of populationEstonia: 11.3 pupils per teacher, 2.5% of populationEthiopia: 55.1 pupils per teacher, 19.7% of populationFinland: 13.7 pupils per teacher, 2.5% of populationFiji: 28 pupils per teacher, 6.8% of populationFrance: 18.2 pupils per teacher, 2.5% of populationGabon: 24.5 pupils per teacher, 25.3% of populationUnited Kingdom: 15.1 pupils per teacher, 2.5% of populationGeorgia: 8.98 pupils per teacher, 2.5% of populationGhana: 27 pupils per teacher, 6.3% of populationGuinea: 47.1 pupils per teacher, 11.4% of populationGambia, The: 36.1 pupils per teacher, 16.8% of populationGuinea-Bissau: 51.9 pupils per teacher, 22.1% of populationGreece: 9.38 pupils per teacher, 2.5% of populationGuatemala: 20.3 pupils per teacher, 11.8% of populationGuyana: 23.2 pupils per teacher, 2.5% of populationHong Kong SAR, China: 13.3 pupils per teacher, 3.1% of populationHonduras: 25.6 pupils per teacher, 14.8% of populationCroatia: 13.5 pupils per teacher, 2.5% of populationHungary: 10.8 pupils per teacher, 2.5% of populationIndonesia: 17 pupils per teacher, 6.3% of populationIndia: 32.7 pupils per teacher, 12% of populationIreland: 16.1 pupils per teacher, 2.5% of populationIran, Islamic Rep.: 28.5 pupils per teacher, 6.8% of populationIceland: 10.1 pupils per teacher, 2.5% of populationIsrael: 12.1 pupils per teacher, 2.5% of populationItaly: 11.5 pupils per teacher, 2.5% of populationJamaica: 24.8 pupils per teacher, 7.7% of populationJordan: 18.5 pupils per teacher, 14.3% of populationKazakhstan: 17.2 pupils per teacher, 2.5% of populationKenya: 30.7 pupils per teacher, 36.8% of populationKyrgyz Republic: 25 pupils per teacher, 5.1% of populationCambodia: 41.7 pupils per teacher, 5.2% of populationKiribati: 25.5 pupils per teacher, 4.1% of populationKorea, Rep.: 16.3 pupils per teacher, 2.5% of populationKuwait: 8.88 pupils per teacher, 2.5% of populationLebanon: 12.5 pupils per teacher, 8.7% of populationLiberia: 22.3 pupils per teacher, 35.5% of populationSri Lanka: 21.7 pupils per teacher, 7.4% of populationLithuania: 13.5 pupils per teacher, 2.5% of populationLuxembourg: 8.3 pupils per teacher, 2.5% of populationLatvia: 11.5 pupils per teacher, 2.5% of populationMacao SAR, China: 13.5 pupils per teacher, 11.2% of populationMorocco: 26.8 pupils per teacher, 7% of populationMoldova: 17.9 pupils per teacher, 2.5% of populationMadagascar: 39.8 pupils per teacher, 39.5% of populationMexico: 26.6 pupils per teacher, 2.7% of populationNorth Macedonia: 14.9 pupils per teacher, 2.5% of populationMali: 37.8 pupils per teacher, 12.3% of populationMalta: 12.9 pupils per teacher, 2.5% of populationMyanmar: 24.4 pupils per teacher, 5.4% of populationMongolia: 30.4 pupils per teacher, 2.5% of populationMozambique: 55.3 pupils per teacher, 21.8% of populationMauritania: 34.3 pupils per teacher, 8.7% of populationMauritius: 16.2 pupils per teacher, 8.7% of populationMalawi: 58.7 pupils per teacher, 21.4% of populationMalaysia: 11.7 pupils per teacher, 2.5% of populationNamibia: 25.1 pupils per teacher, 18.1% of populationNiger: 36.3 pupils per teacher, 12.9% of populationNigeria: 37.6 pupils per teacher, 19.9% of populationNicaragua: 30.2 pupils per teacher, 17.3% of populationNetherlands: 11.8 pupils per teacher, 2.5% of populationNorway: 8.59 pupils per teacher, 2.5% of populationNepal: 19.7 pupils per teacher, 5.3% of populationNew Zealand: 14.9 pupils per teacher, 2.5% of populationOman: 9.67 pupils per teacher, 5.9% of populationPakistan: 44.1 pupils per teacher, 16.5% of populationPanama: 22 pupils per teacher, 5.7% of populationPeru: 17.4 pupils per teacher, 6.9% of populationPhilippines: 29.1 pupils per teacher, 3% of populationPapua New Guinea: 35.5 pupils per teacher, 28.7% of populationPoland: 10.2 pupils per teacher, 2.5% of populationPortugal: 12.4 pupils per teacher, 2.5% of populationParaguay: 24.2 pupils per teacher, 5.2% of populationRomania: 19.3 pupils per teacher, 2.5% of populationRussian Federation: 21.3 pupils per teacher, 2.5% of populationRwanda: 59.5 pupils per teacher, 24.4% of populationSaudi Arabia: 13.8 pupils per teacher, 2.5% of populationSenegal: 36.3 pupils per teacher, 5.1% of populationSolomon Islands: 25.4 pupils per teacher, 20% of populationSierra Leone: 27.5 pupils per teacher, 24.1% of populationEl Salvador: 26.9 pupils per teacher, 6.7% of populationSerbia: 14.3 pupils per teacher, 2.5% of populationSao Tome and Principe: 31.2 pupils per teacher, 17.4% of populationSuriname: 13.4 pupils per teacher, 9.7% of populationSlovak Republic: 15.5 pupils per teacher, 3.1% of populationSlovenia: 13.8 pupils per teacher, 2.5% of populationSweden: 12.2 pupils per teacher, 2.5% of populationEswatini: 26.6 pupils per teacher, 14.7% of populationSeychelles: 14.5 pupils per teacher, 2.5% of populationChad: 56.9 pupils per teacher, 32% of populationTogo: 40.1 pupils per teacher, 9.1% of populationThailand: 16.6 pupils per teacher, 4.6% of populationTajikistan: 22.3 pupils per teacher, 8.4% of populationTimor-Leste: 26.9 pupils per teacher, 18.7% of populationTunisia: 16.9 pupils per teacher, 3% of populationTurkiye: 17 pupils per teacher, 2.5% of populationTanzania: 50.6 pupils per teacher, 20.2% of populationUganda: 42.7 pupils per teacher, 22% of populationUkraine: 13 pupils per teacher, 6.9% of populationUruguay: 11 pupils per teacher, 2.5% of populationUnited States: 14.2 pupils per teacher, 2.5% of populationUzbekistan: 21.5 pupils per teacher, 2.5% of populationSt. Vincent and the Grenadines: 14.4 pupils per teacher, 6.1% of populationViet Nam: 20.3 pupils per teacher, 5.3% of populationVanuatu: 26.6 pupils per teacher, 7.2% of populationSamoa: 30.2 pupils per teacher, 3.6% of populationSouth Africa: 30.3 pupils per teacher, 10% of populationZambia: 42.1 pupils per teacher, 37.2% of populationZimbabwe: 36.4 pupils per teacher, 19.7% of populationCAFCMRCODKENKHMKWTLBRLUXMDGNORTCD

best-fit line line after adjusting

Four ways to measure the link

MethodrpCountries
Standard (Pearson), not adjusted+0.6843.4e-22151
By rank (Spearman), not adjusted+0.7553.7e-29151
Standard (Pearson), adjusted for national income+0.2240.006151
By rank (Spearman), adjusted for national income+0.1890.021151

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 151 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: +0.461 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from +0.201 (without AGO) to +0.279 (without LBR). 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: LBR (+0.055).

Fragile: this link may not hold up.
  • direction is not consistent across regions
  • much weaker within regions than across them (largely a between-region difference)
  • much weaker within income groups than across them (mostly a gap between richer and poorer countries)

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.

nr
East Asia & Pacific20+0.03
Europe & Central Asia46-0.05
Latin America & Caribbean23+0.07
Middle East, North Africa, Afghanistan & Pakistan16+0.38
Sub-Saharan Africa41-0.03

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.

nr
Poorest third51+0.18
Middle third50+0.07
Richest third50+0.06

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.

nr
Christians94+0.13
Muslims38+0.41

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.

nr
France22+0.21
Never a European colony19+0.09
Spain17-0.38
United Kingdom41+0.30

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 = +0.298 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.

Loading…

Over time, within countries

Everything above compares countries with each other at one moment. This section compares each country only with itself over 19years. So a link here can’t come from anything about a country that stays the same, such as its history, geography, institutions or culture.

Within countries over time, there is no link that is clearly more than chance (r = +0.139, comparing each country only with itself over the years, and each year only with the same year elsewhere). Whatever the cross-country picture shows, countries whose pupil-teacher ratio moved did not tend to see their undernourishment move with it.

Across countries (adjusted)+0.224for comparison
Within countries+0.344each country vs itself
…and vs the same year elsewhere+0.139q = 0.261 · 146 countries
Year-on-year changes+0.112q = 0.133
Read with care.
  • Almost all of the second indicator's variation is between countries, 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.

2,019 country-years (one country in one year), 146 countries, 2001–2019, about 14 years each on average. Share of the variation that happens within countries over time: 14% for Pupil-teacher ratio, 5% for Undernourishment. 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

0.20−0.2-100+10years Undernourishment trails Pupil-teacher ratio →lag -10: r = -0.010 (n = 811)lag -9: r = 0.032 (n = 912)lag -8: r = 0.049 (n = 1,047)lag -7: r = 0.052 (n = 1,188)lag -6: r = 0.057 (n = 1,309)lag -5: r = 0.057 (n = 1,416)lag -4: r = 0.073 (n = 1,528)lag -3: r = 0.103 (n = 1,658)lag -2: r = 0.106 (n = 1,775)lag -1: r = 0.116 (n = 1,889)lag +0: r = 0.139 (n = 2,019)lag +1: r = 0.121 (n = 2,134)lag +2: r = 0.080 (n = 2,263)lag +3: r = 0.020 (n = 2,372)lag +4: r = -0.010 (n = 2,457)lag +5: r = -0.025 (n = 2,546)lag +6: r = -0.032 (n = 2,578)lag +7: r = -0.029 (n = 2,562)lag +8: r = -0.026 (n = 2,542)lag +9: r = -0.029 (n = 2,536)lag +10: r = -0.029 (n = 2,534)

Same year (lag 0): +0.139. 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


pupils per teacher
% of population		Years
Central African Republic CAF83.429.8%2016, 2023
Rwanda RWA59.524.4%2018, 2023
Malawi MWI58.721.4%2018, 2023
Chad TCD56.932%2016, 2023
Mozambique MOZ55.321.8%2018, 2023
Ethiopia ETH55.119.7%2011, 2023
Guinea-Bissau GNB51.922.1%2010, 2023
Tanzania TZA50.620.2%2018, 2023
Angola AGO5022.5%2015, 2023
Afghanistan AFG48.828.1%2018, 2023
Guinea GIN47.111.4%2016, 2023
Cameroon CMR44.84.8%2018, 2023
Congo, Rep. COG44.426.4%2012, 2023
Pakistan PAK44.116.5%2018, 2023
Uganda UGA42.722%2017, 2023

World Bank, World Development Indicators
World Bank, World Development Indicators

Sources

Pupil-teacher ratio

Pupil-teacher ratio, primary

UNESCO Institute for Statistics · CC BY 4.0 · updated quarterly

The World Bank's copy stops at 2019.

Undernourishment

Prevalence of undernourishment (% of population)

Food and Agriculture Organization · CC BY 4.0 · updated quarterly

Estimated from the food supply and how it is shared out, not by asking anyone. It is the FAO's model of how many people get less food energy than they need. The survey-based food insecurity measure below is treated as measuring the same thing. So their pair reads as two tools agreeing, not as a finding.

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 Pupil-teacher ratio and Undernourishment

This page shows that two measures go together. It does not show that Pupil-teacher ratio changes Undernourishment, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.

More links with Pupil-teacher ratio or Undernourishment