placestats

Electricity access vs. Pupil-teacher ratio

Holds up after adjusting for income

Across 180 countries, Electricity access and Pupil-teacher ratio rise and fall together at r = -0.76 (on a scale from −1 to +1, where 0 means no link). Comparing only countries with similar income (GDP per person) shrinks it to -0.43 (q = 0.0037, allowing for the many pairs tested). Much of the first figure is that both measures rise with national income, but a moderate negative link remains. Caution: correlation moves sharply once outliers are trimmed.

Comparing countries across the middle half of electricity access, 90% to 100% of population, pupil-teacher ratio is better by 4.54 pupils per teacher at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 2.3 pupils per teacher.

Link before adjusting (r)-0.761p = 3.0e-35 · 180 countries
After adjusting for national income-0.431p = 1.8e-9 · likely range [-0.54, -0.30]
p, allowing for regions6.3e-5standard error 0.044 · 7 regions
Check for luck (q)0.004across 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.

Electricity access · % of populationlink with income +0.79 · 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

Electricity access · % of population →Pupil-teacher ratio · pupils per teacher →13.4%100%6.9383.4Aruba: 100% of population, 14.8 pupils per teacherAfghanistan: 87.8% of population, 48.8 pupils per teacherAngola: 55.5% of population, 50 pupils per teacherAlbania: 100% of population, 17.6 pupils per teacherAndorra: 100% of population, 10.5 pupils per teacherUnited Arab Emirates: 100% of population, 24.5 pupils per teacherArmenia: 100% of population, 15.4 pupils per teacherAntigua and Barbuda: 100% of population, 12.4 pupils per teacherAustria: 100% of population, 10 pupils per teacherAzerbaijan: 100% of population, 15.4 pupils per teacherBurundi: 20.1% of population, 42.5 pupils per teacherBelgium: 100% of population, 11.3 pupils per teacherBenin: 59% of population, 39.2 pupils per teacherBurkina Faso: 34% of population, 39.7 pupils per teacherBangladesh: 99.5% of population, 30.1 pupils per teacherBulgaria: 100% of population, 15.2 pupils per teacherBahrain: 100% of population, 11.9 pupils per teacherBahamas, The: 100% of population, 19.4 pupils per teacherBosnia and Herzegovina: 100% of population, 16.9 pupils per teacherBelarus: 100% of population, 19.2 pupils per teacherBelize: 99.6% of population, 19.8 pupils per teacherBermuda: 100% of population, 10.4 pupils per teacherBolivia: 96.6% of population, 17.8 pupils per teacherBrazil: 99.8% of population, 20.2 pupils per teacherBarbados: 100% of population, 14 pupils per teacherBrunei Darussalam: 100% of population, 9.9 pupils per teacherBhutan: 100% of population, 34.7 pupils per teacherBotswana: 80.2% of population, 23.7 pupils per teacherCentral African Republic: 18.2% of population, 83.4 pupils per teacherSwitzerland: 100% of population, 9.93 pupils per teacherChile: 99% of population, 17.8 pupils per teacherChina: 100% of population, 16.4 pupils per teacherCote d'Ivoire: 72.9% of population, 41.8 pupils per teacherCameroon: 72% of population, 44.8 pupils per teacherCongo, Dem. Rep.: 22.5% of population, 33.2 pupils per teacherCongo, Rep.: 53% of population, 44.4 pupils per teacherColombia: 98.9% of population, 23.3 pupils per teacherComoros: 91.7% of population, 28.1 pupils per teacherCabo Verde: 98.4% of population, 21.1 pupils per teacherCosta Rica: 99.8% of population, 12.2 pupils per teacherCayman Islands: 100% of population, 15.7 pupils per teacherCyprus: 100% of population, 12 pupils per teacherCzechia: 100% of population, 18.9 pupils per teacherGermany: 100% of population, 12.3 pupils per teacherDjibouti: 69.2% of population, 29.4 pupils per teacherDominica: 100% of population, 13.1 pupils per teacherDenmark: 100% of population, 10.7 pupils per teacherDominican Republic: 99.5% of population, 18.9 pupils per teacherAlgeria: 100% of population, 24.3 pupils per teacherEcuador: 98.5% of population, 24.3 pupils per teacherEgypt, Arab Rep.: 100% of population, 23.7 pupils per teacherSpain: 100% of population, 13.1 pupils per teacherEstonia: 100% of population, 11.3 pupils per teacherEthiopia: 56.6% of population, 55.1 pupils per teacherFinland: 100% of population, 13.7 pupils per teacherFiji: 95.9% of population, 28 pupils per teacherFrance: 100% of population, 18.2 pupils per teacherMicronesia, Fed. Sts.: 88.9% of population, 19.7 pupils per teacherGabon: 95.1% of population, 24.5 pupils per teacherUnited Kingdom: 100% of population, 15.1 pupils per teacherGeorgia: 100% of population, 8.98 pupils per teacherGhana: 91.9% of population, 27 pupils per teacherGuinea: 53.8% of population, 47.1 pupils per teacherGambia, The: 69% of population, 36.1 pupils per teacherGuinea-Bissau: 43.7% of population, 51.9 pupils per teacherEquatorial Guinea: 65.1% of population, 23.2 pupils per teacherGreece: 100% of population, 9.38 pupils per teacherGrenada: 95.6% of population, 16.4 pupils per teacherGuatemala: 90.9% of population, 20.3 pupils per teacherGuyana: 93% of population, 23.2 pupils per teacherHong Kong SAR, China: 100% of population, 13.3 pupils per teacherHonduras: 95.5% of population, 25.6 pupils per teacherCroatia: 100% of population, 13.5 pupils per teacherHungary: 100% of population, 10.8 pupils per teacherIndonesia: 99.9% of population, 17 pupils per teacherIndia: 99.9% of population, 32.7 pupils per teacherIreland: 100% of population, 16.1 pupils per teacherIran, Islamic Rep.: 100% of population, 28.5 pupils per teacherIceland: 100% of population, 10.1 pupils per teacherIsrael: 100% of population, 12.1 pupils per teacherItaly: 100% of population, 11.5 pupils per teacherJamaica: 97.7% of population, 24.8 pupils per teacherJordan: 100% of population, 18.5 pupils per teacherJapan: 100% of population, 15.7 pupils per teacherKazakhstan: 100% of population, 17.2 pupils per teacherKenya: 77% of population, 30.7 pupils per teacherKyrgyz Republic: 100% of population, 25 pupils per teacherCambodia: 99.2% of population, 41.7 pupils per teacherKiribati: 97.7% of population, 25.5 pupils per teacherSt. Kitts and Nevis: 100% of population, 13.9 pupils per teacherKorea, Rep.: 100% of population, 16.3 pupils per teacherKuwait: 100% of population, 8.88 pupils per teacherLao PDR: 96.5% of population, 22.3 pupils per teacherLebanon: 100% of population, 12.5 pupils per teacherLiberia: 34.9% of population, 22.3 pupils per teacherSt. Lucia: 100% of population, 14.7 pupils per teacherSri Lanka: 100% of population, 21.7 pupils per teacherLesotho: 60.6% of population, 32.9 pupils per teacherLithuania: 100% of population, 13.5 pupils per teacherLuxembourg: 100% of population, 8.3 pupils per teacherLatvia: 100% of population, 11.5 pupils per teacherMacao SAR, China: 100% of population, 13.5 pupils per teacherMorocco: 100% of population, 26.8 pupils per teacherMoldova: 100% of population, 17.9 pupils per teacherMadagascar: 42.5% of population, 39.8 pupils per teacherMaldives: 100% of population, 10.2 pupils per teacherMexico: 99.8% of population, 26.6 pupils per teacherNorth Macedonia: 100% of population, 14.9 pupils per teacherMali: 49.5% of population, 37.8 pupils per teacherMalta: 100% of population, 12.9 pupils per teacherMyanmar: 80.4% of population, 24.4 pupils per teacherMongolia: 99.1% of population, 30.4 pupils per teacherMozambique: 36.9% of population, 55.3 pupils per teacherMauritania: 52.2% of population, 34.3 pupils per teacherMauritius: 100% of population, 16.2 pupils per teacherMalawi: 15.6% of population, 58.7 pupils per teacherMalaysia: 100% of population, 11.7 pupils per teacherNamibia: 59.3% of population, 25.1 pupils per teacherNiger: 21.3% of population, 36.3 pupils per teacherNigeria: 62.5% of population, 37.6 pupils per teacherNicaragua: 88.7% of population, 30.2 pupils per teacherNetherlands: 100% of population, 11.8 pupils per teacherNorway: 100% of population, 8.59 pupils per teacherNepal: 97.9% of population, 19.7 pupils per teacherNaoero: 100% of population, 40.2 pupils per teacherNew Zealand: 100% of population, 14.9 pupils per teacherOman: 100% of population, 9.67 pupils per teacherPakistan: 95.7% of population, 44.1 pupils per teacherPanama: 96% of population, 22 pupils per teacherPeru: 96.5% of population, 17.4 pupils per teacherPhilippines: 94.8% of population, 29.1 pupils per teacherPapua New Guinea: 43.3% of population, 35.5 pupils per teacherPoland: 100% of population, 10.2 pupils per teacherPuerto Rico (US): 100% of population, 13.5 pupils per teacherPortugal: 100% of population, 12.4 pupils per teacherParaguay: 99.8% of population, 24.2 pupils per teacherWest Bank and Gaza: 100% of population, 24.5 pupils per teacherQatar: 100% of population, 12.2 pupils per teacherRomania: 100% of population, 19.3 pupils per teacherRussian Federation: 100% of population, 21.3 pupils per teacherRwanda: 72% of population, 59.5 pupils per teacherSaudi Arabia: 100% of population, 13.8 pupils per teacherSenegal: 82.9% of population, 36.3 pupils per teacherSingapore: 100% of population, 14.7 pupils per teacherSolomon Islands: 81.5% of population, 25.4 pupils per teacherSierra Leone: 39.2% of population, 27.5 pupils per teacherEl Salvador: 98.7% of population, 26.9 pupils per teacherSan Marino: 100% of population, 6.93 pupils per teacherSerbia: 100% of population, 14.3 pupils per teacherSao Tome and Principe: 77.7% of population, 31.2 pupils per teacherSuriname: 99% of population, 13.4 pupils per teacherSlovak Republic: 100% of population, 15.5 pupils per teacherSlovenia: 100% of population, 13.8 pupils per teacherSweden: 100% of population, 12.2 pupils per teacherEswatini: 89.3% of population, 26.6 pupils per teacherSint Maarten (Dutch part): 100% of population, 11.3 pupils per teacherSeychelles: 100% of population, 14.5 pupils per teacherTurks and Caicos Islands: 100% of population, 17.7 pupils per teacherChad: 13.4% of population, 56.9 pupils per teacherTogo: 61.1% of population, 40.1 pupils per teacherThailand: 100% of population, 16.6 pupils per teacherTajikistan: 99.9% of population, 22.3 pupils per teacherTimor-Leste: 94.3% of population, 26.9 pupils per teacherTonga: 100% of population, 21.6 pupils per teacherTunisia: 100% of population, 16.9 pupils per teacherTurkiye: 100% of population, 17 pupils per teacherTuvalu: 100% of population, 15.6 pupils per teacherTanzania: 52.4% of population, 50.6 pupils per teacherUganda: 55.3% of population, 42.7 pupils per teacherUkraine: 100% of population, 13 pupils per teacherUruguay: 100% of population, 11 pupils per teacherUnited States: 100% of population, 14.2 pupils per teacherUzbekistan: 100% of population, 21.5 pupils per teacherSt. Vincent and the Grenadines: 100% of population, 14.4 pupils per teacherViet Nam: 100% of population, 20.3 pupils per teacherVanuatu: 65.5% of population, 26.6 pupils per teacherSamoa: 100% of population, 30.2 pupils per teacherSouth Africa: 90.2% of population, 30.3 pupils per teacherZambia: 53.6% of population, 42.1 pupils per teacherZimbabwe: 62% of population, 36.4 pupils per teacherAFGCAFCODLBRLUXMWINERNORPAKRWASMRTCD

best-fit line line after adjusting

Four ways to measure the link

MethodrpCountries
Standard (Pearson), not adjusted-0.7613.0e-35180
By rank (Spearman), not adjusted-0.7925.7e-40180
Standard (Pearson), adjusted for national income-0.4311.8e-9180
By rank (Spearman), adjusted for national income-0.3906.8e-8180

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: +0.330 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from -0.468 (without LBR) to -0.398 (without CAF). 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 (-0.037).

Fragile: this link may not hold up.
  • correlation moves sharply once outliers are trimmed
  • much weaker within regions than across them (largely a between-region difference)

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 & Pacific28-0.10
Europe & Central Asia48+0.02
Latin America & Caribbean33-0.43
Middle East, North Africa, Afghanistan & Pakistan19-0.23
Sub-Saharan Africa44-0.21

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.

nr
Poorest third60-0.43
Middle third60-0.13
Richest third60-0.46

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
Christians104-0.48
Muslims43-0.42

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
France23-0.33
Never a European colony20-0.02
Spain19-0.01
United Kingdom56-0.43

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 = -0.193 after dropping 35 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 = -0.117, 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 electricity access moved did not tend to see their pupil-teacher ratio move with it.

Across countries (adjusted)-0.431for comparison
Within countries-0.358each country vs itself
…and vs the same year elsewhere-0.117q = 0.197 · 185 countries
Year-on-year changes+0.008q = 0.857
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.

3,258 country-years (one country in one year), 185 countries, 1990–2019, about 18 years each on average. Share of the variation that happens within countries over time: 5% for Electricity access, 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

0.20−0.2-100+10years Pupil-teacher ratio trails Electricity access →lag -10: r = 0.069 (n = 3,216)lag -9: r = 0.048 (n = 3,337)lag -8: r = 0.024 (n = 3,453)lag -7: r = -0.012 (n = 3,567)lag -6: r = -0.048 (n = 3,616)lag -5: r = -0.057 (n = 3,572)lag -4: r = -0.069 (n = 3,527)lag -3: r = -0.084 (n = 3,478)lag -2: r = -0.091 (n = 3,423)lag -1: r = -0.105 (n = 3,348)lag +0: r = -0.117 (n = 3,258)lag +1: r = -0.113 (n = 3,142)lag +2: r = -0.106 (n = 3,025)lag +3: r = -0.107 (n = 2,904)lag +4: r = -0.096 (n = 2,786)lag +5: r = -0.098 (n = 2,654)lag +6: r = -0.124 (n = 2,539)lag +7: r = -0.150 (n = 2,430)lag +8: r = -0.148 (n = 2,307)lag +9: r = -0.166 (n = 2,180)lag +10: r = -0.177 (n = 2,035)

Same year (lag 0): -0.117. 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.

This curve peaks at the edge of the window (lag +10), so it is still drifting where the search stops. That pattern usually reflects a slow trend left over in the data, not a link with real timing. The peak value should not be read as the “true” link at the right lag.

The data


% of population
pupils per teacher		Years
Samoa WSM100%30.22024, 2010
Viet Nam VNM100%20.32024, 2018
St. Vincent and the Grenadines VCT100%14.42024, 2018
Uzbekistan UZB100%21.52024, 2018
United States USA100%14.22024, 2017
Uruguay URY100%112024, 2017
Ukraine UKR100%132024, 2018
Tuvalu TUV100%15.62024, 2018
Turkiye TUR100%172024, 2017
Tunisia TUN100%16.92024, 2018
Tonga TON100%21.62024, 2015
Thailand THA100%16.62024, 2018
Turks and Caicos Islands TCA100%17.72024, 2018
Seychelles SYC100%14.52024, 2018
Sint Maarten (Dutch part) SXM100%11.32024, 2012

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

Sources

Electricity access

Access to electricity (% of population)

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 Electricity access and Pupil-teacher ratio

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

More links with Electricity access or Pupil-teacher ratio