placestats

Basic water access vs. Married by 18

Fades after adjusting for income

Across 134 countries, Basic water access and Married by 18 rise and fall together at r = -0.61 (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, which could easily be chance (q = 0.072, 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 basic water access, 78.9% to 98.7% of population, married by 18 is better by 11.5% of women aged 20-24 at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 6.63% of women aged 20-24.

Link before adjusting (r)-0.609p = 5.7e-15 · 134 countries
After adjusting for national income-0.284p = 0.001 · likely range [-0.43, -0.12]
p, allowing for regions0.010standard error 0.070 · 6 regions
Check for luck (q)0.072across 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
Married by 18 · % of women aged 20-24link with income -0.60 · moderate

“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 →Married by 18 · % of women aged 20-24 →35.7%100%0%76.3%Afghanistan: 80.8% of population, 28.7% of women aged 20-24Angola: 68% of population, 23.1% of women aged 20-24Albania: 95.1% of population, 11.8% of women aged 20-24Argentina: 99% of population, 15.5% of women aged 20-24Armenia: 99.9% of population, 5.3% of women aged 20-24Azerbaijan: 97.7% of population, 15% of women aged 20-24Burundi: 65.9% of population, 19% of women aged 20-24Belgium: 100% of population, 0.1% of women aged 20-24Benin: 69.6% of population, 27.5% of women aged 20-24Burkina Faso: 50% of population, 38.2% of women aged 20-24Bangladesh: 98.8% of population, 47.2% of women aged 20-24Bosnia and Herzegovina: 96.1% of population, 3.5% of women aged 20-24Belarus: 99.9% of population, 4.7% of women aged 20-24Belize: 94.8% of population, 33.5% of women aged 20-24Bolivia: 93.4% of population, 14.5% of women aged 20-24Barbados: 99.2% of population, 29.2% of women aged 20-24Bhutan: 99.5% of population, 9% of women aged 20-24Central African Republic: 36.5% of population, 61% of women aged 20-24Chile: 99.1% of population, 0% of women aged 20-24China: 96.1% of population, 2.8% of women aged 20-24Cote d'Ivoire: 77.2% of population, 25.8% of women aged 20-24Cameroon: 71.4% of population, 29.8% of women aged 20-24Congo, Dem. Rep.: 35.7% of population, 29.9% of women aged 20-24Congo, Rep.: 73.5% of population, 27.3% of women aged 20-24Colombia: 97.1% of population, 23.4% of women aged 20-24Comoros: 85.1% of population, 20.7% of women aged 20-24Cabo Verde: 92.3% of population, 8.4% of women aged 20-24Costa Rica: 99.8% of population, 17.1% of women aged 20-24Djibouti: 79.7% of population, 6.5% of women aged 20-24Denmark: 100% of population, 0.7% of women aged 20-24Dominican Republic: 97.5% of population, 31.5% of women aged 20-24Algeria: 92.4% of population, 3.8% of women aged 20-24Ecuador: 92.1% of population, 22.2% of women aged 20-24Egypt, Arab Rep.: 97.3% of population, 15.8% of women aged 20-24Ethiopia: 55.6% of population, 40.3% of women aged 20-24Finland: 100% of population, 0.1% of women aged 20-24Fiji: 95.6% of population, 4% of women aged 20-24Gabon: 88.6% of population, 13.3% of women aged 20-24United Kingdom: 100% of population, 0% of women aged 20-24Georgia: 97.3% of population, 9.4% of women aged 20-24Ghana: 89.9% of population, 16.1% of women aged 20-24Guinea: 74.2% of population, 46.5% of women aged 20-24Gambia, The: 87.1% of population, 23.1% of women aged 20-24Guinea-Bissau: 61.8% of population, 25.7% of women aged 20-24Equatorial Guinea: 64.7% of population, 29.5% of women aged 20-24Guatemala: 93.2% of population, 29.5% of women aged 20-24Guyana: 95.6% of population, 32.3% of women aged 20-24Honduras: 95.7% of population, 34% of women aged 20-24Haiti: 73.3% of population, 14.9% of women aged 20-24Indonesia: 89% of population, 16.3% of women aged 20-24India: 95.7% of population, 22.3% of women aged 20-24Iran, Islamic Rep.: 97.9% of population, 16.7% of women aged 20-24Iraq: 98.4% of population, 27.9% of women aged 20-24Israel: 100% of population, 0.8% of women aged 20-24Jamaica: 87.6% of population, 26.9% of women aged 20-24Jordan: 99.3% of population, 9.9% of women aged 20-24Kazakhstan: 97.8% of population, 6.1% of women aged 20-24Kenya: 65.6% of population, 12.5% of women aged 20-24Kyrgyz Republic: 94.9% of population, 9.2% of women aged 20-24Cambodia: 82.8% of population, 17.9% of women aged 20-24Kiribati: 79.1% of population, 18.4% of women aged 20-24Lao PDR: 95.9% of population, 30.5% of women aged 20-24Lebanon: 92.6% of population, 6% of women aged 20-24Liberia: 78.8% of population, 24.9% of women aged 20-24Libya: 96.4% of population, 4.1% of women aged 20-24St. Lucia: 98.1% of population, 24% of women aged 20-24Sri Lanka: 90.2% of population, 9.8% of women aged 20-24Lesotho: 78.1% of population, 13.4% of women aged 20-24Lithuania: 99.9% of population, 0.2% of women aged 20-24Morocco: 92.2% of population, 13.7% of women aged 20-24Moldova: 92.7% of population, 12.2% of women aged 20-24Madagascar: 55.3% of population, 38.8% of women aged 20-24Maldives: 99.8% of population, 2.2% of women aged 20-24Mexico: 99.5% of population, 18.2% of women aged 20-24North Macedonia: 98.2% of population, 7.5% of women aged 20-24Mali: 86.4% of population, 48.5% of women aged 20-24Myanmar: 85.7% of population, 16% of women aged 20-24Montenegro: 99.3% of population, 5.8% of women aged 20-24Mongolia: 86.1% of population, 8.1% of women aged 20-24Mozambique: 66.6% of population, 48.4% of women aged 20-24Mauritania: 77.3% of population, 36.6% of women aged 20-24Malawi: 73.1% of population, 38.7% of women aged 20-24Namibia: 86.5% of population, 6.9% of women aged 20-24Niger: 53.4% of population, 76.3% of women aged 20-24Nigeria: 82.2% of population, 33.4% of women aged 20-24Norway: 100% of population, 0% of women aged 20-24Nepal: 93.6% of population, 34.9% of women aged 20-24Naoero: 97.8% of population, 18.2% of women aged 20-24Oman: 92.7% of population, 4% of women aged 20-24Pakistan: 90.7% of population, 18.3% of women aged 20-24Panama: 95.3% of population, 26.4% of women aged 20-24Peru: 95.6% of population, 17.9% of women aged 20-24Philippines: 95.9% of population, 9.4% of women aged 20-24Papua New Guinea: 53.3% of population, 27.3% of women aged 20-24Paraguay: 99.6% of population, 21.6% of women aged 20-24West Bank and Gaza: 98.8% of population, 13.4% of women aged 20-24Qatar: 100% of population, 1.7% of women aged 20-24Romania: 100% of population, 6.9% of women aged 20-24Russian Federation: 96.9% of population, 6.2% of women aged 20-24Rwanda: 61.4% of population, 5.5% of women aged 20-24Saudi Arabia: 99% of population, 3.4% of women aged 20-24Sudan: 64.9% of population, 34.2% of women aged 20-24Senegal: 88% of population, 30.2% of women aged 20-24Singapore: 100% of population, 0.1% of women aged 20-24Solomon Islands: 71.6% of population, 21.3% of women aged 20-24Sierra Leone: 68.1% of population, 29.6% of women aged 20-24El Salvador: 91.6% of population, 19.7% of women aged 20-24Serbia: 95.4% of population, 5.5% of women aged 20-24Sao Tome and Principe: 78% of population, 28% of women aged 20-24Suriname: 98% of population, 36% of women aged 20-24Eswatini: 80.4% of population, 1.9% of women aged 20-24Turks and Caicos Islands: 98.8% of population, 23.3% of women aged 20-24Chad: 52.2% of population, 60.6% of women aged 20-24Togo: 64.8% of population, 24.8% of women aged 20-24Thailand: 100% of population, 17% of women aged 20-24Tajikistan: 89.2% of population, 8.8% of women aged 20-24Turkmenistan: 99.9% of population, 6.1% of women aged 20-24Timor-Leste: 87.3% of population, 14.9% of women aged 20-24Tonga: 98.9% of population, 10.1% of women aged 20-24Trinidad and Tobago: 99.3% of population, 4.2% of women aged 20-24Tunisia: 96.7% of population, 2.4% of women aged 20-24Turkiye: 96% of population, 14.7% of women aged 20-24Tuvalu: 98.7% of population, 1.8% of women aged 20-24Tanzania: 64.6% of population, 29.1% of women aged 20-24Uganda: 63% of population, 34% of women aged 20-24Ukraine: 93.5% of population, 9.1% of women aged 20-24Uruguay: 99.6% of population, 24.6% of women aged 20-24Uzbekistan: 97.3% of population, 3.4% of women aged 20-24Viet Nam: 98.8% of population, 14.6% of women aged 20-24Vanuatu: 87.1% of population, 20.9% of women aged 20-24Samoa: 99.4% of population, 7.4% of women aged 20-24South Africa: 90.2% of population, 3.6% of women aged 20-24Zambia: 73.4% of population, 23.9% of women aged 20-24Zimbabwe: 67.2% of population, 33.7% of women aged 20-24BGDCAFCODGBRKENMLINERNORRWASGPSURTCD

best-fit line line after adjusting

Four ways to measure the link

MethodrpCountries
Standard (Pearson), not adjusted-0.6095.7e-15134
By rank (Spearman), not adjusted-0.5831.5e-13134
Standard (Pearson), adjusted for national income-0.2840.001134
By rank (Spearman), adjusted for national income-0.1990.022134

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 134 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: +0.326 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from -0.319 (without BGD) to -0.249 (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: BGD (-0.036).

Fragile: this link may not hold up.
  • direction is not consistent across regions

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 & Pacific20-0.37
Europe & Central Asia25-0.34
Latin America & Caribbean24+0.04
Middle East, North Africa, Afghanistan & Pakistan17+0.18
Sub-Saharan Africa42-0.31

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 third45-0.39
Middle third44-0.09
Richest third45-0.04

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
Christians75-0.26
Muslims42-0.46

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.

nr
France24-0.22
Never a European colony19-0.41
Spain18-0.26
United Kingdom43-0.21

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 = -0.181 after dropping 4 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 0years. So a link here can’t come from anything about a country that stays the same, such as its history, geography, institutions or culture.

Not enough history inside each country to look at this over time. That needs countries measured for several years in a row, and at least one of these measures is measured too rarely.

The data


% of population
% of women aged 20-24		Years
Thailand THA100%17%2024, 2022
Singapore SGP100%0.1%2024, 2025
Norway NOR100%0%2024, 2022
Belgium BEL100%0.1%2024, 2020
Denmark DNK100%0.7%2024, 2021
Romania ROU100%6.9%2024, 2021
Israel ISR100%0.8%2024, 2022
United Kingdom GBR100%0%2024, 2021
Finland FIN100%0.1%2024, 2017
Qatar QAT100%1.7%2024, 2023
Armenia ARM99.9%5.3%2024, 2016
Turkmenistan TKM99.9%6.1%2024
Lithuania LTU99.9%0.2%2024, 2022
Belarus BLR99.9%4.7%2024, 2019
Costa Rica CRI99.8%17.1%2024, 2018

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

Married by 18

Women who were first married by age 18 (% of women ages 20-24)

UNICEF · CC BY 4.0 · updated quarterly

From household surveys, mostly in lower-income countries, and only in years a survey ran. No year reaches sixty countries, so the latest value used is up to a decade old for some. Rich countries rarely report it at all, which shapes any link with income.

How this was computed

Data used: most recent value in 2010-2025; values come from 2010–2025. 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 6 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 Married by 18

This page shows that two measures go together. It does not show that Basic water access changes Married by 18, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.

More links with Basic water access or Married by 18