placestats

Basic water access vs. Road traffic deaths

Holds up after adjusting for income

Across 182 countries, Basic water access and Road traffic deaths rise and fall together at r = -0.62 (on a scale from −1 to +1, where 0 means no link). Comparing only countries with similar income (GDP per person) shrinks it to -0.24 (q = 0.036, 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. Caution: direction is not consistent across regions.

Comparing countries across the middle half of basic water access, 86.7% to 99.6% of population, road traffic deaths is better by 6.24 per 100,000 population at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 2.95 per 100,000 population.

Link before adjusting (r)-0.625p = 4.4e-21 · 182 countries
After adjusting for national income-0.243p = 0.001 · likely range [-0.38, -0.10]
p, allowing for regions0.003standard error 0.049 · 7 regions
Check for luck (q)0.036across 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
Road traffic deaths · per 100,000 populationlink with income -0.71 · high

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 →Road traffic deaths · per 100,000 population →35.7%100%064.6Afghanistan: 80.8% of population, 15.9 per 100,000 populationAngola: 68% of population, 26.1 per 100,000 populationAlbania: 95.1% of population, 11.7 per 100,000 populationAndorra: 100% of population, 7.6 per 100,000 populationUnited Arab Emirates: 100% of population, 8.9 per 100,000 populationArgentina: 99% of population, 14.1 per 100,000 populationArmenia: 99.9% of population, 20 per 100,000 populationAntigua and Barbuda: 98.9% of population, 0 per 100,000 populationAustralia: 100% of population, 4.9 per 100,000 populationAustria: 100% of population, 4.9 per 100,000 populationAzerbaijan: 97.7% of population, 6.7 per 100,000 populationBurundi: 65.9% of population, 35.5 per 100,000 populationBelgium: 100% of population, 5.8 per 100,000 populationBenin: 69.6% of population, 26.8 per 100,000 populationBurkina Faso: 50% of population, 31 per 100,000 populationBangladesh: 98.8% of population, 15.3 per 100,000 populationBulgaria: 99.2% of population, 9.2 per 100,000 populationBahrain: 99.9% of population, 5.2 per 100,000 populationBahamas, The: 98.9% of population, 7.7 per 100,000 populationBosnia and Herzegovina: 96.1% of population, 13.5 per 100,000 populationBelarus: 99.9% of population, 7.6 per 100,000 populationBelize: 94.8% of population, 22.6 per 100,000 populationBolivia: 93.4% of population, 21.1 per 100,000 populationBrazil: 100% of population, 16 per 100,000 populationBarbados: 99.2% of population, 8.2 per 100,000 populationBrunei Darussalam: 100% of population, 7.5 per 100,000 populationBhutan: 99.5% of population, 16.2 per 100,000 populationBotswana: 91.8% of population, 26.4 per 100,000 populationCentral African Republic: 36.5% of population, 37.7 per 100,000 populationCanada: 98.3% of population, 5.3 per 100,000 populationSwitzerland: 100% of population, 2.2 per 100,000 populationChile: 99.1% of population, 14.9 per 100,000 populationChina: 96.1% of population, 17.4 per 100,000 populationCote d'Ivoire: 77.2% of population, 24.1 per 100,000 populationCameroon: 71.4% of population, 30.2 per 100,000 populationCongo, Dem. Rep.: 35.7% of population, 34.9 per 100,000 populationCongo, Rep.: 73.5% of population, 29.7 per 100,000 populationColombia: 97.1% of population, 15.4 per 100,000 populationComoros: 85.1% of population, 26.6 per 100,000 populationCabo Verde: 92.3% of population, 26.8 per 100,000 populationCosta Rica: 99.8% of population, 14.8 per 100,000 populationCyprus: 99.7% of population, 5.8 per 100,000 populationCzechia: 98.7% of population, 5.9 per 100,000 populationGermany: 100% of population, 3.8 per 100,000 populationDjibouti: 79.7% of population, 23.5 per 100,000 populationDominica: 97% of population, 10.9 per 100,000 populationDenmark: 100% of population, 3.7 per 100,000 populationDominican Republic: 97.5% of population, 64.6 per 100,000 populationAlgeria: 92.4% of population, 20.9 per 100,000 populationEcuador: 92.1% of population, 20.1 per 100,000 populationEgypt, Arab Rep.: 97.3% of population, 10.1 per 100,000 populationSpain: 99.9% of population, 3.9 per 100,000 populationEstonia: 100% of population, 4.5 per 100,000 populationEthiopia: 55.6% of population, 28.2 per 100,000 populationFinland: 100% of population, 3.9 per 100,000 populationFiji: 95.6% of population, 13.5 per 100,000 populationFrance: 100% of population, 5.1 per 100,000 populationMicronesia, Fed. Sts.: 89.9% of population, 0.2 per 100,000 populationGabon: 88.6% of population, 23.9 per 100,000 populationUnited Kingdom: 100% of population, 3.2 per 100,000 populationGeorgia: 97.3% of population, 12.4 per 100,000 populationGhana: 89.9% of population, 25.7 per 100,000 populationGuinea: 74.2% of population, 29.7 per 100,000 populationGambia, The: 87.1% of population, 29.6 per 100,000 populationGuinea-Bissau: 61.8% of population, 32.2 per 100,000 populationEquatorial Guinea: 64.7% of population, 27.2 per 100,000 populationGreece: 100% of population, 8.3 per 100,000 populationGrenada: 95.6% of population, 8 per 100,000 populationGuatemala: 93.2% of population, 22.9 per 100,000 populationGuyana: 95.6% of population, 22.3 per 100,000 populationHonduras: 95.7% of population, 16.1 per 100,000 populationCroatia: 99.9% of population, 7.9 per 100,000 populationHaiti: 73.3% of population, 18.8 per 100,000 populationHungary: 100% of population, 7.7 per 100,000 populationIndonesia: 89% of population, 11.3 per 100,000 populationIndia: 95.7% of population, 15.6 per 100,000 populationIreland: 97.1% of population, 3.1 per 100,000 populationIran, Islamic Rep.: 97.9% of population, 21.5 per 100,000 populationIraq: 98.4% of population, 27.3 per 100,000 populationIceland: 100% of population, 2 per 100,000 populationIsrael: 100% of population, 3.9 per 100,000 populationItaly: 99.9% of population, 5.3 per 100,000 populationJamaica: 87.6% of population, 15.1 per 100,000 populationJordan: 99.3% of population, 17 per 100,000 populationJapan: 99.2% of population, 3.6 per 100,000 populationKazakhstan: 97.8% of population, 12.7 per 100,000 populationKenya: 65.6% of population, 28.3 per 100,000 populationKyrgyz Republic: 94.9% of population, 12.7 per 100,000 populationCambodia: 82.8% of population, 19.6 per 100,000 populationKiribati: 79.1% of population, 1.9 per 100,000 populationKorea, Rep.: 100% of population, 8.6 per 100,000 populationKuwait: 100% of population, 15.4 per 100,000 populationLao PDR: 95.9% of population, 17.9 per 100,000 populationLebanon: 92.6% of population, 16.4 per 100,000 populationLiberia: 78.8% of population, 38.9 per 100,000 populationLibya: 96.4% of population, 21.3 per 100,000 populationSt. Lucia: 98.1% of population, 29.8 per 100,000 populationSri Lanka: 90.2% of population, 19.7 per 100,000 populationLesotho: 78.1% of population, 31.9 per 100,000 populationLithuania: 99.9% of population, 8.1 per 100,000 populationLuxembourg: 100% of population, 4.1 per 100,000 populationLatvia: 98.8% of population, 8.1 per 100,000 populationMorocco: 92.2% of population, 17 per 100,000 populationMoldova: 92.7% of population, 7.3 per 100,000 populationMadagascar: 55.3% of population, 29.2 per 100,000 populationMaldives: 99.8% of population, 1.6 per 100,000 populationMexico: 99.5% of population, 12.8 per 100,000 populationMarshall Islands: 87.4% of population, 5.7 per 100,000 populationNorth Macedonia: 98.2% of population, 5.1 per 100,000 populationMali: 86.4% of population, 22.7 per 100,000 populationMalta: 100% of population, 4.1 per 100,000 populationMyanmar: 85.7% of population, 20.4 per 100,000 populationMontenegro: 99.3% of population, 7.6 per 100,000 populationMongolia: 86.1% of population, 21 per 100,000 populationMozambique: 66.6% of population, 30 per 100,000 populationMauritania: 77.3% of population, 25.6 per 100,000 populationMauritius: 99.9% of population, 12.2 per 100,000 populationMalawi: 73.1% of population, 33.4 per 100,000 populationMalaysia: 97.9% of population, 22.5 per 100,000 populationNamibia: 86.5% of population, 34.8 per 100,000 populationNiger: 53.4% of population, 25.5 per 100,000 populationNigeria: 82.2% of population, 20.7 per 100,000 populationNetherlands: 100% of population, 4 per 100,000 populationNorway: 100% of population, 2.1 per 100,000 populationNepal: 93.6% of population, 16.3 per 100,000 populationNew Zealand: 100% of population, 9.6 per 100,000 populationOman: 92.7% of population, 10.6 per 100,000 populationPakistan: 90.7% of population, 13 per 100,000 populationPanama: 95.3% of population, 13.9 per 100,000 populationPeru: 95.6% of population, 13.6 per 100,000 populationPhilippines: 95.9% of population, 12 per 100,000 populationPalau: 99.5% of population, 4.78 per 100,000 populationPapua New Guinea: 53.3% of population, 12.6 per 100,000 populationPoland: 90.1% of population, 9.4 per 100,000 populationPortugal: 99.3% of population, 8.2 per 100,000 populationParaguay: 99.6% of population, 22 per 100,000 populationWest Bank and Gaza: 98.8% of population, 5.3 per 100,000 populationQatar: 100% of population, 7.3 per 100,000 populationRomania: 100% of population, 10.3 per 100,000 populationRussian Federation: 96.9% of population, 12 per 100,000 populationRwanda: 61.4% of population, 29.4 per 100,000 populationSaudi Arabia: 99% of population, 35.9 per 100,000 populationSudan: 64.9% of population, 26.8 per 100,000 populationSenegal: 88% of population, 23.5 per 100,000 populationSingapore: 100% of population, 2.1 per 100,000 populationSolomon Islands: 71.6% of population, 16.5 per 100,000 populationSierra Leone: 68.1% of population, 33 per 100,000 populationEl Salvador: 91.6% of population, 20.9 per 100,000 populationSan Marino: 100% of population, 0 per 100,000 populationSomalia, Fed. Rep.: 75.3% of population, 27.4 per 100,000 populationSerbia: 95.4% of population, 7.5 per 100,000 populationSao Tome and Principe: 78% of population, 27.9 per 100,000 populationSuriname: 98% of population, 15.3 per 100,000 populationSlovak Republic: 99.8% of population, 6.1 per 100,000 populationSlovenia: 99.6% of population, 5.1 per 100,000 populationSweden: 99.8% of population, 3.1 per 100,000 populationEswatini: 80.4% of population, 33.5 per 100,000 populationSeychelles: 97.7% of population, 11.3 per 100,000 populationSyrian Arab Republic: 94.1% of population, 14.9 per 100,000 populationChad: 52.2% of population, 32.4 per 100,000 populationTogo: 64.8% of population, 28.7 per 100,000 populationThailand: 100% of population, 32.2 per 100,000 populationTajikistan: 89.2% of population, 15.7 per 100,000 populationTurkmenistan: 99.9% of population, 13.5 per 100,000 populationTimor-Leste: 87.3% of population, 11.9 per 100,000 populationTonga: 98.9% of population, 33 per 100,000 populationTrinidad and Tobago: 99.3% of population, 9.3 per 100,000 populationTunisia: 96.7% of population, 16.5 per 100,000 populationTurkiye: 96% of population, 6.7 per 100,000 populationTanzania: 64.6% of population, 31.1 per 100,000 populationUganda: 63% of population, 29.4 per 100,000 populationUkraine: 93.5% of population, 10.2 per 100,000 populationUruguay: 99.6% of population, 14.8 per 100,000 populationUnited States: 100% of population, 12.7 per 100,000 populationUzbekistan: 97.3% of population, 11.7 per 100,000 populationSt. Vincent and the Grenadines: 97.7% of population, 7.4 per 100,000 populationViet Nam: 98.8% of population, 30.6 per 100,000 populationVanuatu: 87.1% of population, 14.9 per 100,000 populationSamoa: 99.4% of population, 13 per 100,000 populationSouth Africa: 90.2% of population, 22.2 per 100,000 populationZambia: 73.4% of population, 20.5 per 100,000 populationZimbabwe: 67.2% of population, 41.2 per 100,000 populationATGBFACAFCODDOMKIRMDVPNGSAUSMRTHA

best-fit line line after adjusting

Four ways to measure the link

MethodrpCountries
Standard (Pearson), not adjusted-0.6254.4e-21182
By rank (Spearman), not adjusted-0.6941.9e-27182
Standard (Pearson), adjusted for national income-0.2430.001182
By rank (Spearman), adjusted for national income-0.2280.002182

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 182 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: +0.382 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from -0.290 (without DOM) to -0.219 (without PSE). 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: DOM (-0.047).

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 & Pacific27+0.21
Europe & Central Asia50+0.01
Latin America & Caribbean29-0.08
Middle East, North Africa, Afghanistan & Pakistan22-0.16
Sub-Saharan Africa46-0.26

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 third61-0.47
Middle third60-0.20
Richest third61-0.25

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
Christians107-0.18
Muslims49-0.46

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
France25-0.65
Never a European colony21-0.20
Spain19-0.20
United Kingdom60-0.17

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 = -0.293 after dropping 19 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 20years. 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 shows up within countries over time (r = +0.172) but mostly disappears in year-to-year changes (r = +0.039). That points to slow trends particular to each country, not the two measures moving together from year to year.

Across countries (adjusted)-0.243for comparison
Within countries-0.051each country vs itself
…and vs the same year elsewhere+0.172q = 0.002 · 182 countries
Year-on-year changes+0.039q = 0.018
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.

3,585 country-years (one country in one year), 182 countries, 2000–2019, about 20 years each on average. Share of the variation that happens within countries over time: 4% for Basic water access, 12% for Road traffic deaths. 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 Road traffic deaths trails Basic water access →lag -10: r = 0.135 (n = 2,680)lag -9: r = 0.140 (n = 2,861)lag -8: r = 0.143 (n = 3,042)lag -7: r = 0.151 (n = 3,222)lag -6: r = 0.154 (n = 3,402)lag -5: r = 0.155 (n = 3,581)lag -4: r = 0.157 (n = 3,584)lag -3: r = 0.161 (n = 3,586)lag -2: r = 0.165 (n = 3,588)lag -1: r = 0.169 (n = 3,587)lag +0: r = 0.172 (n = 3,585)lag +1: r = 0.174 (n = 3,408)lag +2: r = 0.175 (n = 3,230)lag +3: r = 0.172 (n = 3,050)lag +4: r = 0.169 (n = 2,868)lag +5: r = 0.167 (n = 2,682)lag +6: r = 0.162 (n = 2,501)lag +7: r = 0.156 (n = 2,320)lag +8: r = 0.128 (n = 2,135)lag +9: r = 0.100 (n = 1,955)lag +10: r = 0.079 (n = 1,771)

Same year (lag 0): +0.172. 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
per 100,000 population		Years
Thailand THA100%32.22024, 2019
Singapore SGP100%2.12024, 2019
New Zealand NZL100%9.62024, 2019
Norway NOR100%2.12024, 2019
Netherlands NLD100%42024, 2019
Malta MLT100%4.12024, 2019
Luxembourg LUX100%4.12024, 2019
Kuwait KWT100%15.42024, 2019
Korea, Rep. KOR100%8.62024, 2019
Iceland ISL100%22024, 2019
Hungary HUN100%7.72024, 2019
Greece GRC100%8.32024, 2019
Germany DEU100%3.82024, 2019
Brunei Darussalam BRN100%7.52024, 2019
Belgium BEL100%5.82024, 2019

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

Road traffic deaths

Mortality from road traffic injury (per 100,000 population)

World Health Organization · 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 2013–2024. 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 Road traffic deaths

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

More links with Basic water access or Road traffic deaths