placestats

Basic water access vs. Child stunting

Holds up after adjusting for income

Across 156 countries, Basic water access and Child stunting rise and fall together at r = -0.74 (on a scale from −1 to +1, where 0 means no link). Comparing only countries with similar income (GDP per person) shrinks it to -0.36 (q = 0.030, 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 basic water access, 81.9% to 99.1% of population, child stunting is better by 11% of children under 5 at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 5.39% of children under 5.

Link before adjusting (r)-0.739p = 3.4e-28 · 156 countries
After adjusting for national income-0.363p = 3.5e-6 · likely range [-0.49, -0.22]
p, allowing for regions0.002standard error 0.069 · 7 regions
Check for luck (q)0.030across 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.

Basic water access · % of populationlink with income +0.85 · proxy
Child stunting · % of children under 5link with income -0.80 · 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

Basic water access · % of population →Child stunting · % of children under 5 →35.7%100%1%55.3%Afghanistan: 80.8% of population, 42% of children under 5Angola: 68% of population, 47.7% of children under 5Albania: 95.1% of population, 7.4% of children under 5Argentina: 99% of population, 10.7% of children under 5Armenia: 99.9% of population, 6.2% of children under 5Australia: 100% of population, 3.1% of children under 5Azerbaijan: 97.7% of population, 6.8% of children under 5Burundi: 65.9% of population, 55.3% of children under 5Belgium: 100% of population, 2.6% of children under 5Benin: 69.6% of population, 33.2% of children under 5Burkina Faso: 50% of population, 19.5% of children under 5Bangladesh: 98.8% of population, 25.1% of children under 5Bulgaria: 99.2% of population, 5.5% of children under 5Bahrain: 99.9% of population, 4.6% of children under 5Bosnia and Herzegovina: 96.1% of population, 7.9% of children under 5Belarus: 99.9% of population, 1.1% of children under 5Belize: 94.8% of population, 11.7% of children under 5Bolivia: 93.4% of population, 10.7% of children under 5Brazil: 100% of population, 8.9% of children under 5Barbados: 99.2% of population, 5.8% of children under 5Brunei Darussalam: 100% of population, 9.9% of children under 5Bhutan: 99.5% of population, 17.9% of children under 5Botswana: 91.8% of population, 21% of children under 5Central African Republic: 36.5% of population, 38.9% of children under 5Chile: 99.1% of population, 1.7% of children under 5China: 96.1% of population, 4.5% of children under 5Cote d'Ivoire: 77.2% of population, 20.3% of children under 5Cameroon: 71.4% of population, 27.2% of children under 5Congo, Dem. Rep.: 35.7% of population, 44.1% of children under 5Congo, Rep.: 73.5% of population, 16.3% of children under 5Colombia: 97.1% of population, 11.6% of children under 5Comoros: 85.1% of population, 17.4% of children under 5Cabo Verde: 92.3% of population, 5.3% of children under 5Costa Rica: 99.8% of population, 10.6% of children under 5Czechia: 98.7% of population, 2.4% of children under 5Germany: 100% of population, 2.2% of children under 5Djibouti: 79.7% of population, 20.9% of children under 5Dominican Republic: 97.5% of population, 5.6% of children under 5Algeria: 92.4% of population, 8.9% of children under 5Ecuador: 92.1% of population, 17.7% of children under 5Egypt, Arab Rep.: 97.3% of population, 12.9% of children under 5Estonia: 100% of population, 1.3% of children under 5Ethiopia: 55.6% of population, 35.5% of children under 5Finland: 100% of population, 1.7% of children under 5Fiji: 95.6% of population, 7.2% of children under 5Gabon: 88.6% of population, 13.7% of children under 5United Kingdom: 100% of population, 3.5% of children under 5Georgia: 97.3% of population, 4.7% of children under 5Ghana: 89.9% of population, 15.6% of children under 5Guinea: 74.2% of population, 26.6% of children under 5Gambia, The: 87.1% of population, 14% of children under 5Guinea-Bissau: 61.8% of population, 28.3% of children under 5Equatorial Guinea: 64.7% of population, 17.1% of children under 5Greece: 100% of population, 2% of children under 5Guatemala: 93.2% of population, 44.6% of children under 5Guyana: 95.6% of population, 7.1% of children under 5Honduras: 95.7% of population, 17.9% of children under 5Haiti: 73.3% of population, 21.6% of children under 5Indonesia: 89% of population, 22.6% of children under 5India: 95.7% of population, 32.9% of children under 5Ireland: 97.1% of population, 2.2% of children under 5Iran, Islamic Rep.: 97.9% of population, 4.8% of children under 5Iraq: 98.4% of population, 9.4% of children under 5Jamaica: 87.6% of population, 6.9% of children under 5Jordan: 99.3% of population, 7.7% of children under 5Japan: 99.2% of population, 5.2% of children under 5Kazakhstan: 97.8% of population, 4.4% of children under 5Kenya: 65.6% of population, 17.9% of children under 5Kyrgyz Republic: 94.9% of population, 11% of children under 5Cambodia: 82.8% of population, 22% of children under 5Kiribati: 79.1% of population, 14.7% of children under 5Korea, Rep.: 100% of population, 1.8% of children under 5Kuwait: 100% of population, 4.5% of children under 5Lao PDR: 95.9% of population, 29.9% of children under 5Lebanon: 92.6% of population, 10.1% of children under 5Liberia: 78.8% of population, 26.9% of children under 5Libya: 96.4% of population, 9.2% of children under 5St. Lucia: 98.1% of population, 2.8% of children under 5Sri Lanka: 90.2% of population, 10.1% of children under 5Lesotho: 78.1% of population, 35% of children under 5Lithuania: 99.9% of population, 1.6% of children under 5Latvia: 98.8% of population, 1.7% of children under 5Morocco: 92.2% of population, 13.7% of children under 5Moldova: 92.7% of population, 4.2% of children under 5Madagascar: 55.3% of population, 38.4% of children under 5Maldives: 99.8% of population, 14.2% of children under 5Mexico: 99.5% of population, 13.1% of children under 5Marshall Islands: 87.4% of population, 30% of children under 5North Macedonia: 98.2% of population, 3.8% of children under 5Mali: 86.4% of population, 23.2% of children under 5Malta: 100% of population, 3.5% of children under 5Myanmar: 85.7% of population, 24.5% of children under 5Montenegro: 99.3% of population, 8% of children under 5Mongolia: 86.1% of population, 7.1% of children under 5Mozambique: 66.6% of population, 37% of children under 5Mauritania: 77.3% of population, 21.5% of children under 5Mauritius: 99.9% of population, 7.8% of children under 5Malawi: 73.1% of population, 33.2% of children under 5Malaysia: 97.9% of population, 24.3% of children under 5Namibia: 86.5% of population, 16.4% of children under 5Niger: 53.4% of population, 48.3% of children under 5Nigeria: 82.2% of population, 33.8% of children under 5Netherlands: 100% of population, 1.6% of children under 5Nepal: 93.6% of population, 26% of children under 5Naoero: 97.8% of population, 16% of children under 5Oman: 92.7% of population, 12.9% of children under 5Pakistan: 90.7% of population, 33.6% of children under 5Panama: 95.3% of population, 14% of children under 5Peru: 95.6% of population, 10.6% of children under 5Philippines: 95.9% of population, 27.7% of children under 5Papua New Guinea: 53.3% of population, 47.6% of children under 5Poland: 90.1% of population, 1% of children under 5Portugal: 99.3% of population, 3.2% of children under 5Paraguay: 99.6% of population, 3.2% of children under 5West Bank and Gaza: 98.8% of population, 8% of children under 5Qatar: 100% of population, 5.4% of children under 5Romania: 100% of population, 7% of children under 5Rwanda: 61.4% of population, 29.8% of children under 5Saudi Arabia: 99% of population, 11.1% of children under 5Sudan: 64.9% of population, 35.4% of children under 5Senegal: 88% of population, 17.2% of children under 5Singapore: 100% of population, 2.8% of children under 5Solomon Islands: 71.6% of population, 29.8% of children under 5Sierra Leone: 68.1% of population, 25.2% of children under 5El Salvador: 91.6% of population, 9.4% of children under 5Somalia, Fed. Rep.: 75.3% of population, 23.9% of children under 5Serbia: 95.4% of population, 4.6% of children under 5Sao Tome and Principe: 78% of population, 10% of children under 5Suriname: 98% of population, 8% of children under 5Eswatini: 80.4% of population, 18.9% of children under 5Seychelles: 97.7% of population, 6.2% of children under 5Syrian Arab Republic: 94.1% of population, 23.5% of children under 5Turks and Caicos Islands: 98.8% of population, 3.2% of children under 5Chad: 52.2% of population, 31.5% of children under 5Togo: 64.8% of population, 23% of children under 5Thailand: 100% of population, 12.3% of children under 5Tajikistan: 89.2% of population, 13.1% of children under 5Turkmenistan: 99.9% of population, 6.5% of children under 5Timor-Leste: 87.3% of population, 45.4% of children under 5Tonga: 98.9% of population, 1.6% of children under 5Trinidad and Tobago: 99.3% of population, 7.8% of children under 5Tunisia: 96.7% of population, 8.9% of children under 5Turkiye: 96% of population, 5.5% of children under 5Tuvalu: 98.7% of population, 5.3% of children under 5Tanzania: 64.6% of population, 29.9% of children under 5Uganda: 63% of population, 23.5% of children under 5Ukraine: 93.5% of population, 11.7% of children under 5Uruguay: 99.6% of population, 6.5% of children under 5United States: 100% of population, 4.2% of children under 5Uzbekistan: 97.3% of population, 6.7% of children under 5Viet Nam: 98.8% of population, 19.2% of children under 5Vanuatu: 87.1% of population, 31% of children under 5Samoa: 99.4% of population, 8.4% of children under 5South Africa: 90.2% of population, 24.4% of children under 5Zambia: 73.4% of population, 32.3% of children under 5Zimbabwe: 67.2% of population, 23.7% of children under 5BFABLRCAFCODESTGNQGTMINDNERNLDTLS

best-fit line line after adjusting

Four ways to measure the link

MethodrpCountries
Standard (Pearson), not adjusted-0.7393.4e-28156
By rank (Spearman), not adjusted-0.7652.8e-31156
Standard (Pearson), adjusted for national income-0.3633.5e-6156
By rank (Spearman), adjusted for national income-0.2960.000156

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 156 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: +0.376 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from -0.393 (without BFA) to -0.328 (without PNG). 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: PNG (+0.035).

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 & Pacific26-0.48
Europe & Central Asia32-0.12
Latin America & Caribbean25-0.14
Middle East, North Africa, Afghanistan & Pakistan20-0.62
Sub-Saharan Africa46-0.38

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 third52-0.33
Middle third52-0.39
Richest third52-0.09

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.

nr
Christians86-0.37
Muslims48-0.44

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
France25-0.20
Never a European colony21-0.49
Spain18-0.11
United Kingdom52-0.48

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 = -0.303 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 25years. 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 also shows up within countries over time (r = -0.368). It holds even when looking only at changes from one year to the next (r = -0.295). This is the strongest kind of evidence available here: it holds when each country is compared only with itself, and it is not just a product of shared trends.

Across countries (adjusted)-0.363for comparison
Within countries-0.659each country vs itself
…and vs the same year elsewhere-0.368q = 1.0e-5 · 162 countries
Year-on-year changes-0.295q = 0.000
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.

3,963 country-years (one country in one year), 162 countries, 2000–2024, about 25 years each on average. Share of the variation that happens within countries over time: 8% for Basic water access, 9% for Child stunting. 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

0.40−0.4-100+10years Child stunting trails Basic water access →lag -10: r = -0.367 (n = 2,396)lag -9: r = -0.372 (n = 2,556)lag -8: r = -0.376 (n = 2,716)lag -7: r = -0.378 (n = 2,875)lag -6: r = -0.378 (n = 3,034)lag -5: r = -0.379 (n = 3,192)lag -4: r = -0.377 (n = 3,347)lag -3: r = -0.375 (n = 3,502)lag -2: r = -0.372 (n = 3,657)lag -1: r = -0.371 (n = 3,810)lag +0: r = -0.368 (n = 3,963)lag +1: r = -0.362 (n = 3,806)lag +2: r = -0.356 (n = 3,648)lag +3: r = -0.350 (n = 3,490)lag +4: r = -0.342 (n = 3,331)lag +5: r = -0.334 (n = 3,168)lag +6: r = -0.324 (n = 3,010)lag +7: r = -0.313 (n = 2,852)lag +8: r = -0.302 (n = 2,693)lag +9: r = -0.290 (n = 2,532)lag +10: r = -0.279 (n = 2,367)

Same year (lag 0): -0.368. 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


% of population
% of children under 5		Years
Thailand THA100%12.3%2024
Singapore SGP100%2.8%2024
Netherlands NLD100%1.6%2024
Malta MLT100%3.5%2024
Kuwait KWT100%4.5%2024
Korea, Rep. KOR100%1.8%2024
Greece GRC100%2%2024
Germany DEU100%2.2%2024
Brunei Darussalam BRN100%9.9%2024
Belgium BEL100%2.6%2024
Romania ROU100%7%2024
United Kingdom GBR100%3.5%2024
Brazil BRA100%8.9%2024
Estonia EST100%1.3%2024
Finland FIN100%1.7%2024

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

Sources

Basic water access

People using at least basic drinking water services (% of population)

World Bank · CC BY 4.0 · updated quarterly

Child stunting

Prevalence of stunting, height for age, modelled estimate (% of children under 5)

UNICEF, WHO and World Bank Joint Child Malnutrition Estimates · CC BY 4.0 · updated quarterly

An estimate from a statistical model. The agencies fit a model to household surveys and predict every country and year. So this is smoother than the surveys behind it, and it has values for years nobody measured. The survey-only series never reaches sixty countries in any year.

How this was computed

Data used: most recent value in 2010-2025; values come from 2016–2024. 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 Basic water access and Child stunting

This page shows that two measures go together. It does not show that Basic water access changes Child stunting, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.

More links with Basic water access or Child stunting