placestats

Fertility rate vs. Pupil-teacher ratio

Holds up after adjusting for income

Across 180 countries, Fertility rate and Pupil-teacher ratio rise and fall together at r = +0.81 (on a scale from −1 to +1, where 0 means no link). Comparing only countries with similar income (GDP per person) shrinks it to +0.45 (q = 0.0014, allowing for the many pairs tested). Much of the first figure is that both measures rise with national income, but a moderate positive link remains.

Comparing countries across the middle half of fertility rate, 1.44 to 3.17 births per woman, pupil-teacher ratio is worse by 14.7 pupils per teacher at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 8.78 pupils per teacher.

Link before adjusting (r)+0.811p = 3.2e-43 · 180 countries
After adjusting for national income+0.450p = 2.5e-10 · likely range [+0.33, +0.56]
p, allowing for regions1.1e-5standard error 0.034 · 7 regions
Check for luck (q)0.001across 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.

Fertility rate · births per womanlink with income -0.81 · proxy
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

Fertility rate · births per woman →Pupil-teacher ratio · pupils per teacher →0.5826.036.9383.4Aruba: 1.61 births per woman, 14.8 pupils per teacherAfghanistan: 4.76 births per woman, 48.8 pupils per teacherAngola: 5.05 births per woman, 50 pupils per teacherAlbania: 1.34 births per woman, 17.6 pupils per teacherAndorra: 1.09 births per woman, 10.5 pupils per teacherUnited Arab Emirates: 1.21 births per woman, 24.5 pupils per teacherArmenia: 1.7 births per woman, 15.4 pupils per teacherAntigua and Barbuda: 1.58 births per woman, 12.4 pupils per teacherAustria: 1.31 births per woman, 10 pupils per teacherAzerbaijan: 1.43 births per woman, 15.4 pupils per teacherBurundi: 4.79 births per woman, 42.5 pupils per teacherBelgium: 1.44 births per woman, 11.3 pupils per teacherBenin: 4.48 births per woman, 39.2 pupils per teacherBurkina Faso: 4.11 births per woman, 39.7 pupils per teacherBangladesh: 2.14 births per woman, 30.1 pupils per teacherBulgaria: 1.72 births per woman, 15.2 pupils per teacherBahrain: 1.8 births per woman, 11.9 pupils per teacherBahamas, The: 1.37 births per woman, 19.4 pupils per teacherBosnia and Herzegovina: 1.49 births per woman, 16.9 pupils per teacherBelarus: 1.22 births per woman, 19.2 pupils per teacherBelize: 2.02 births per woman, 19.8 pupils per teacherBermuda: 1.41 births per woman, 10.4 pupils per teacherBolivia: 2.52 births per woman, 17.8 pupils per teacherBrazil: 1.61 births per woman, 20.2 pupils per teacherBarbados: 1.71 births per woman, 14 pupils per teacherBrunei Darussalam: 1.73 births per woman, 9.9 pupils per teacherBhutan: 1.45 births per woman, 34.7 pupils per teacherBotswana: 2.7 births per woman, 23.7 pupils per teacherCentral African Republic: 5.95 births per woman, 83.4 pupils per teacherSwitzerland: 1.29 births per woman, 9.93 pupils per teacherChile: 1.14 births per woman, 17.8 pupils per teacherChina: 1.01 births per woman, 16.4 pupils per teacherCote d'Ivoire: 4.23 births per woman, 41.8 pupils per teacherCameroon: 4.26 births per woman, 44.8 pupils per teacherCongo, Dem. Rep.: 5.98 births per woman, 33.2 pupils per teacherCongo, Rep.: 4.11 births per woman, 44.4 pupils per teacherColombia: 1.63 births per woman, 23.3 pupils per teacherComoros: 3.82 births per woman, 28.1 pupils per teacherCabo Verde: 1.51 births per woman, 21.1 pupils per teacherCosta Rica: 1.32 births per woman, 12.2 pupils per teacherCayman Islands: 1.52 births per woman, 15.7 pupils per teacherCyprus: 1.38 births per woman, 12 pupils per teacherCzechia: 1.36 births per woman, 18.9 pupils per teacherGermany: 1.36 births per woman, 12.3 pupils per teacherDjibouti: 2.62 births per woman, 29.4 pupils per teacherDominica: 1.48 births per woman, 13.1 pupils per teacherDenmark: 1.47 births per woman, 10.7 pupils per teacherDominican Republic: 2.22 births per woman, 18.9 pupils per teacherAlgeria: 2.72 births per woman, 24.3 pupils per teacherEcuador: 1.81 births per woman, 24.3 pupils per teacherEgypt, Arab Rep.: 2.73 births per woman, 23.7 pupils per teacherSpain: 1.1 births per woman, 13.1 pupils per teacherEstonia: 1.18 births per woman, 11.3 pupils per teacherEthiopia: 3.91 births per woman, 55.1 pupils per teacherFinland: 1.25 births per woman, 13.7 pupils per teacherFiji: 2.27 births per woman, 28 pupils per teacherFrance: 1.61 births per woman, 18.2 pupils per teacherMicronesia, Fed. Sts.: 2.74 births per woman, 19.7 pupils per teacherGabon: 3.59 births per woman, 24.5 pupils per teacherUnited Kingdom: 1.55 births per woman, 15.1 pupils per teacherGeorgia: 1.8 births per woman, 8.98 pupils per teacherGhana: 3.34 births per woman, 27 pupils per teacherGuinea: 4.13 births per woman, 47.1 pupils per teacherGambia, The: 3.91 births per woman, 36.1 pupils per teacherGuinea-Bissau: 3.76 births per woman, 51.9 pupils per teacherEquatorial Guinea: 4.12 births per woman, 23.2 pupils per teacherGreece: 1.24 births per woman, 9.38 pupils per teacherGrenada: 1.47 births per woman, 16.4 pupils per teacherGuatemala: 2.29 births per woman, 20.3 pupils per teacherGuyana: 2.4 births per woman, 23.2 pupils per teacherHong Kong SAR, China: 0.841 births per woman, 13.3 pupils per teacherHonduras: 2.48 births per woman, 25.6 pupils per teacherCroatia: 1.46 births per woman, 13.5 pupils per teacherHungary: 1.41 births per woman, 10.8 pupils per teacherIndonesia: 2.12 births per woman, 17 pupils per teacherIndia: 1.96 births per woman, 32.7 pupils per teacherIreland: 1.47 births per woman, 16.1 pupils per teacherIran, Islamic Rep.: 1.68 births per woman, 28.5 pupils per teacherIceland: 1.56 births per woman, 10.1 pupils per teacherIsrael: 2.87 births per woman, 12.1 pupils per teacherItaly: 1.18 births per woman, 11.5 pupils per teacherJamaica: 1.35 births per woman, 24.8 pupils per teacherJordan: 2.6 births per woman, 18.5 pupils per teacherJapan: 1.15 births per woman, 15.7 pupils per teacherKazakhstan: 2.98 births per woman, 17.2 pupils per teacherKenya: 3.17 births per woman, 30.7 pupils per teacherKyrgyz Republic: 2.6 births per woman, 25 pupils per teacherCambodia: 2.55 births per woman, 41.7 pupils per teacherKiribati: 3.12 births per woman, 25.5 pupils per teacherSt. Kitts and Nevis: 1.53 births per woman, 13.9 pupils per teacherKorea, Rep.: 0.748 births per woman, 16.3 pupils per teacherKuwait: 1.56 births per woman, 8.88 pupils per teacherLao PDR: 2.4 births per woman, 22.3 pupils per teacherLebanon: 2.23 births per woman, 12.5 pupils per teacherLiberia: 3.86 births per woman, 22.3 pupils per teacherSt. Lucia: 1.39 births per woman, 14.7 pupils per teacherSri Lanka: 1.95 births per woman, 21.7 pupils per teacherLesotho: 2.66 births per woman, 32.9 pupils per teacherLithuania: 1.11 births per woman, 13.5 pupils per teacherLuxembourg: 1.25 births per woman, 8.3 pupils per teacherLatvia: 1.24 births per woman, 11.5 pupils per teacherMacao SAR, China: 0.582 births per woman, 13.5 pupils per teacherMorocco: 2.21 births per woman, 26.8 pupils per teacherMoldova: 1.73 births per woman, 17.9 pupils per teacherMadagascar: 3.91 births per woman, 39.8 pupils per teacherMaldives: 1.56 births per woman, 10.2 pupils per teacherMexico: 1.89 births per woman, 26.6 pupils per teacherNorth Macedonia: 1.4 births per woman, 14.9 pupils per teacherMali: 5.51 births per woman, 37.8 pupils per teacherMalta: 1.01 births per woman, 12.9 pupils per teacherMyanmar: 2.1 births per woman, 24.4 pupils per teacherMongolia: 2.5 births per woman, 30.4 pupils per teacherMozambique: 4.69 births per woman, 55.3 pupils per teacherMauritania: 4.63 births per woman, 34.3 pupils per teacherMauritius: 1.44 births per woman, 16.2 pupils per teacherMalawi: 3.59 births per woman, 58.7 pupils per teacherMalaysia: 1.54 births per woman, 11.7 pupils per teacherNamibia: 3.21 births per woman, 25.1 pupils per teacherNiger: 5.93 births per woman, 36.3 pupils per teacherNigeria: 4.38 births per woman, 37.6 pupils per teacherNicaragua: 2.21 births per woman, 30.2 pupils per teacherNetherlands: 1.43 births per woman, 11.8 pupils per teacherNorway: 1.45 births per woman, 8.59 pupils per teacherNepal: 1.96 births per woman, 19.7 pupils per teacherNaoero: 3.29 births per woman, 40.2 pupils per teacherNew Zealand: 1.57 births per woman, 14.9 pupils per teacherOman: 2.51 births per woman, 9.67 pupils per teacherPakistan: 3.55 births per woman, 44.1 pupils per teacherPanama: 2.11 births per woman, 22 pupils per teacherPeru: 1.97 births per woman, 17.4 pupils per teacherPhilippines: 1.89 births per woman, 29.1 pupils per teacherPapua New Guinea: 3.07 births per woman, 35.5 pupils per teacherPoland: 1.14 births per woman, 10.2 pupils per teacherPuerto Rico (US): 0.92 births per woman, 13.5 pupils per teacherPortugal: 1.41 births per woman, 12.4 pupils per teacherParaguay: 2.42 births per woman, 24.2 pupils per teacherWest Bank and Gaza: 3.25 births per woman, 24.5 pupils per teacherQatar: 1.72 births per woman, 12.2 pupils per teacherRomania: 1.39 births per woman, 19.3 pupils per teacherRussian Federation: 1.42 births per woman, 21.3 pupils per teacherRwanda: 3.65 births per woman, 59.5 pupils per teacherSaudi Arabia: 2.31 births per woman, 13.8 pupils per teacherSenegal: 3.77 births per woman, 36.3 pupils per teacherSingapore: 0.97 births per woman, 14.7 pupils per teacherSolomon Islands: 3.51 births per woman, 25.4 pupils per teacherSierra Leone: 3.7 births per woman, 27.5 pupils per teacherEl Salvador: 1.77 births per woman, 26.9 pupils per teacherSan Marino: 1.16 births per woman, 6.93 pupils per teacherSerbia: 1.64 births per woman, 14.3 pupils per teacherSao Tome and Principe: 3.6 births per woman, 31.2 pupils per teacherSuriname: 2.23 births per woman, 13.4 pupils per teacherSlovak Republic: 1.46 births per woman, 15.5 pupils per teacherSlovenia: 1.52 births per woman, 13.8 pupils per teacherSweden: 1.43 births per woman, 12.2 pupils per teacherEswatini: 2.72 births per woman, 26.6 pupils per teacherSint Maarten (Dutch part): 1.44 births per woman, 11.3 pupils per teacherSeychelles: 1.85 births per woman, 14.5 pupils per teacherTurks and Caicos Islands: 1.45 births per woman, 17.7 pupils per teacherChad: 6.03 births per woman, 56.9 pupils per teacherTogo: 4.12 births per woman, 40.1 pupils per teacherThailand: 1.2 births per woman, 16.6 pupils per teacherTajikistan: 3.04 births per woman, 22.3 pupils per teacherTimor-Leste: 2.63 births per woman, 26.9 pupils per teacherTonga: 3.1 births per woman, 21.6 pupils per teacherTunisia: 1.82 births per woman, 16.9 pupils per teacherTurkiye: 1.48 births per woman, 17 pupils per teacherTuvalu: 3.17 births per woman, 15.6 pupils per teacherTanzania: 4.54 births per woman, 50.6 pupils per teacherUganda: 4.17 births per woman, 42.7 pupils per teacherUkraine: 0.988 births per woman, 13 pupils per teacherUruguay: 1.4 births per woman, 11 pupils per teacherUnited States: 1.63 births per woman, 14.2 pupils per teacherUzbekistan: 3.49 births per woman, 21.5 pupils per teacherSt. Vincent and the Grenadines: 1.76 births per woman, 14.4 pupils per teacherViet Nam: 1.9 births per woman, 20.3 pupils per teacherVanuatu: 3.57 births per woman, 26.6 pupils per teacherSamoa: 3.8 births per woman, 30.2 pupils per teacherSouth Africa: 2.21 births per woman, 30.3 pupils per teacherZambia: 4.04 births per woman, 42.1 pupils per teacherZimbabwe: 3.67 births per woman, 36.4 pupils per teacherCAFCODGNQLUXMACMOZMWINERRWASMRTCD

best-fit line line after adjusting

Four ways to measure the link

MethodrpCountries
Standard (Pearson), not adjusted+0.8113.2e-43180
By rank (Spearman), not adjusted+0.7726.4e-37180
Standard (Pearson), adjusted for national income+0.4502.5e-10180
By rank (Spearman), adjusted for national income+0.2850.000180

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 180 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: +0.360 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from +0.422 (without AGO) to +0.478 (without COD). 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: AGO (-0.028).

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 & Pacific28+0.30
Europe & Central Asia48+0.32
Latin America & Caribbean33+0.36
Middle East, North Africa, Afghanistan & Pakistan19+0.24
Sub-Saharan Africa44+0.33

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 third60+0.47
Middle third60+0.26
Richest third60+0.13

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
Christians104+0.51
Muslims43+0.44

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
France23+0.40
Never a European colony20+0.31
Spain19+0.05
United Kingdom56+0.39

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 = +0.504 after dropping 9 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.

Within countries over time, there is no link that is clearly more than chance (r = +0.055, 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 fertility rate moved did not tend to see their pupil-teacher ratio move with it.

Across countries (adjusted)+0.450for comparison
Within countries+0.322each country vs itself
…and vs the same year elsewhere+0.055q = 0.430 · 191 countries
Year-on-year changes+0.011q = 0.717
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.

3,747 country-years (one country in one year), 191 countries, 1990–2019, about 20 years each on average. Share of the variation that happens within countries over time: 8% for Fertility rate, 10% 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

0.20−0.2-100+10years Pupil-teacher ratio trails Fertility rate →lag -10: r = -0.083 (n = 3,216)lag -9: r = -0.066 (n = 3,358)lag -8: r = -0.052 (n = 3,504)lag -7: r = -0.031 (n = 3,654)lag -6: r = -0.012 (n = 3,743)lag -5: r = -0.001 (n = 3,747)lag -4: r = 0.010 (n = 3,747)lag -3: r = 0.022 (n = 3,747)lag -2: r = 0.035 (n = 3,747)lag -1: r = 0.047 (n = 3,747)lag +0: r = 0.055 (n = 3,747)lag +1: r = 0.070 (n = 3,640)lag +2: r = 0.093 (n = 3,520)lag +3: r = 0.109 (n = 3,398)lag +4: r = 0.126 (n = 3,281)lag +5: r = 0.145 (n = 3,155)lag +6: r = 0.160 (n = 3,036)lag +7: r = 0.161 (n = 2,933)lag +8: r = 0.165 (n = 2,837)lag +9: r = 0.157 (n = 2,716)lag +10: r = 0.152 (n = 2,560)

Same year (lag 0): +0.055. 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 largest value on this curve (+0.17 at lag +8) is higher than the same-year one by 0.11. That gap is not a finding. It is the largest of 21 closely related estimates, and picking the biggest of many tests always makes it look bigger. That is exactly why nothing on this site is ranked or chosen by lag.

The data


births per woman
pupils per teacher		Years
Chad TCD6.0356.92024, 2016
Congo, Dem. Rep. COD5.9833.22024, 2015
Central African Republic CAF5.9583.42024, 2016
Niger NER5.9336.32024, 2017
Mali MLI5.5137.82024, 2018
Angola AGO5.05502024, 2015
Burundi BDI4.7942.52024, 2018
Afghanistan AFG4.7648.82024, 2018
Mozambique MOZ4.6955.32024, 2018
Mauritania MRT4.6334.32024, 2018
Tanzania TZA4.5450.62024, 2018
Benin BEN4.4839.22024, 2018
Nigeria NGA4.3837.62024, 2010
Cameroon CMR4.2644.82024, 2018
Cote d'Ivoire CIV4.2341.82024, 2018

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

Sources

Fertility rate

Fertility rate, total (births per woman)

World Bank · CC BY 4.0 · updated quarterly

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.

How this was computed

Data used: most recent value in 2010-2025; values come from 2010–2024. 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 Fertility rate and Pupil-teacher ratio

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

More links with Fertility rate or Pupil-teacher ratio