placestats

Birth rate vs. Slum share of urban population

Holds up after adjusting for income

Across 184 countries, Birth rate and Slum share of urban population rise and fall together at r = +0.78 (on a scale from −1 to +1, where 0 means no link). Comparing only countries with similar income (GDP per person) shrinks it to +0.41 (q = 0.036, 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. Caution: direction is not consistent across regions.

Comparing countries across the middle half of birth rate, 9.81 to 25.4 per 1,000 people, slum share of urban population is worse by 30.8% of urban population at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 21.8% of urban population.

Link before adjusting (r)+0.780p = 6.7e-39 · 184 countries
After adjusting for national income+0.411p = 7.2e-9 · likely range [+0.28, +0.53]
p, allowing for regions0.003standard error 0.084 · 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.

Birth rate · per 1,000 peoplelink with income -0.85 · proxy
Slum share of urban population · % of urban populationlink with income -0.78 · 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

Birth rate · per 1,000 people →Slum share of urban population · % of urban population →4.746.20%92.5%Aruba: 7.59 per 1,000 people, 0% of urban populationAfghanistan: 35 per 1,000 people, 71.6% of urban populationAngola: 37.2 per 1,000 people, 62.7% of urban populationAlbania: 10.1 per 1,000 people, 2.7% of urban populationAndorra: 6.85 per 1,000 people, 0% of urban populationUnited Arab Emirates: 9.82 per 1,000 people, 0.113% of urban populationArgentina: 11.1 per 1,000 people, 14.5% of urban populationArmenia: 11.1 per 1,000 people, 8.39% of urban populationAntigua and Barbuda: 11.7 per 1,000 people, 2.65% of urban populationAustralia: 10.7 per 1,000 people, 0.035% of urban populationAustria: 8.4 per 1,000 people, 0.0466% of urban populationAzerbaijan: 10 per 1,000 people, 26.9% of urban populationBurundi: 33.2 per 1,000 people, 36.8% of urban populationBelgium: 9.2 per 1,000 people, 0% of urban populationBenin: 33.4 per 1,000 people, 64% of urban populationBurkina Faso: 31.3 per 1,000 people, 87.9% of urban populationBangladesh: 20 per 1,000 people, 51.5% of urban populationBulgaria: 8.3 per 1,000 people, 0.197% of urban populationBahrain: 12 per 1,000 people, 0% of urban populationBosnia and Herzegovina: 7.72 per 1,000 people, 0.313% of urban populationBelarus: 7.03 per 1,000 people, 0.004% of urban populationBelize: 18.1 per 1,000 people, 15.7% of urban populationBermuda: 7.92 per 1,000 people, 0.0776% of urban populationBolivia: 21 per 1,000 people, 46.6% of urban populationBrazil: 12.1 per 1,000 people, 14.9% of urban populationBrunei Darussalam: 13.3 per 1,000 people, 21.6% of urban populationBhutan: 12.5 per 1,000 people, 44.7% of urban populationBotswana: 24.4 per 1,000 people, 39.6% of urban populationCentral African Republic: 46.2 per 1,000 people, 68.9% of urban populationCanada: 8.9 per 1,000 people, 1.1% of urban populationSwitzerland: 8.7 per 1,000 people, 0% of urban populationChile: 8.72 per 1,000 people, 7.32% of urban populationChina: 6.77 per 1,000 people, 26.3% of urban populationCote d'Ivoire: 31.6 per 1,000 people, 48.3% of urban populationCameroon: 33.3 per 1,000 people, 32.7% of urban populationCongo, Dem. Rep.: 40.9 per 1,000 people, 78.4% of urban populationCongo, Rep.: 30.4 per 1,000 people, 75.3% of urban populationColombia: 13.3 per 1,000 people, 9.7% of urban populationComoros: 28.2 per 1,000 people, 48.5% of urban populationCabo Verde: 12.2 per 1,000 people, 46.4% of urban populationCosta Rica: 9.99 per 1,000 people, 3.55% of urban populationCayman Islands: 11.6 per 1,000 people, 5.48% of urban populationCyprus: 10.5 per 1,000 people, 0.272% of urban populationCzechia: 7.7 per 1,000 people, 0.0273% of urban populationGermany: 8.1 per 1,000 people, 0% of urban populationDjibouti: 20.9 per 1,000 people, 48.7% of urban populationDenmark: 9.5 per 1,000 people, 0% of urban populationDominican Republic: 17.6 per 1,000 people, 11.2% of urban populationAlgeria: 18.8 per 1,000 people, 13.2% of urban populationEcuador: 14.8 per 1,000 people, 57.8% of urban populationEgypt, Arab Rep.: 20.9 per 1,000 people, 3.84% of urban populationSpain: 6.5 per 1,000 people, 0.046% of urban populationEstonia: 7.1 per 1,000 people, 0.345% of urban populationEthiopia: 31.5 per 1,000 people, 64.3% of urban populationFinland: 7.8 per 1,000 people, 0% of urban populationFiji: 17.9 per 1,000 people, 9.4% of urban populationFrance: 9.7 per 1,000 people, 0% of urban populationGabon: 27.1 per 1,000 people, 38.8% of urban populationUnited Kingdom: 9.89 per 1,000 people, 0.163% of urban populationGeorgia: 11.3 per 1,000 people, 7.08% of urban populationGhana: 25.9 per 1,000 people, 33.5% of urban populationGuinea: 33.3 per 1,000 people, 44% of urban populationGambia, The: 29.9 per 1,000 people, 37.1% of urban populationGuinea-Bissau: 29.6 per 1,000 people, 59% of urban populationEquatorial Guinea: 30 per 1,000 people, 64.7% of urban populationGreece: 6.6 per 1,000 people, 0.05% of urban populationGuatemala: 20.6 per 1,000 people, 37.6% of urban populationGuyana: 19.9 per 1,000 people, 11.3% of urban populationHonduras: 21.6 per 1,000 people, 31.5% of urban populationCroatia: 8.3 per 1,000 people, 0.527% of urban populationHaiti: 21.9 per 1,000 people, 51.1% of urban populationHungary: 8.2 per 1,000 people, 7.2% of urban populationIndonesia: 15.8 per 1,000 people, 19.4% of urban populationIndia: 16 per 1,000 people, 5.41% of urban populationIreland: 10 per 1,000 people, 8.5% of urban populationIran, Islamic Rep.: 12.6 per 1,000 people, 44.7% of urban populationIraq: 25.6 per 1,000 people, 49.3% of urban populationIceland: 11.2 per 1,000 people, 0% of urban populationItaly: 6.3 per 1,000 people, 0.02% of urban populationJamaica: 11.4 per 1,000 people, 0.883% of urban populationJordan: 20.5 per 1,000 people, 23.4% of urban populationJapan: 5.7 per 1,000 people, 2% of urban populationKazakhstan: 19.5 per 1,000 people, 0.794% of urban populationKenya: 27 per 1,000 people, 40.5% of urban populationKyrgyz Republic: 19.4 per 1,000 people, 2.44% of urban populationCambodia: 20.3 per 1,000 people, 42.3% of urban populationKiribati: 25.3 per 1,000 people, 5.93% of urban populationKorea, Rep.: 4.7 per 1,000 people, 4.5% of urban populationKuwait: 10 per 1,000 people, 0% of urban populationLao PDR: 20.9 per 1,000 people, 54.8% of urban populationLebanon: 16 per 1,000 people, 4.53% of urban populationLiberia: 30.6 per 1,000 people, 60.5% of urban populationLibya: 16.5 per 1,000 people, 16.6% of urban populationSt. Lucia: 11.2 per 1,000 people, 0.441% of urban populationSri Lanka: 10.1 per 1,000 people, 44.7% of urban populationLesotho: 23.8 per 1,000 people, 25.6% of urban populationLithuania: 6.6 per 1,000 people, 0.509% of urban populationLuxembourg: 9.5 per 1,000 people, 0.0173% of urban populationLatvia: 6.9 per 1,000 people, 0.593% of urban populationMorocco: 16.4 per 1,000 people, 10.9% of urban populationMoldova: 10.6 per 1,000 people, 6.5% of urban populationMadagascar: 31.7 per 1,000 people, 65.7% of urban populationMaldives: 10.6 per 1,000 people, 34.8% of urban populationMexico: 15.5 per 1,000 people, 17.6% of urban populationMarshall Islands: 20.1 per 1,000 people, 2.38% of urban populationNorth Macedonia: 8.8 per 1,000 people, 0.278% of urban populationMali: 39.5 per 1,000 people, 92.5% of urban populationMalta: 7.7 per 1,000 people, 0.0375% of urban populationMyanmar: 16.5 per 1,000 people, 58.3% of urban populationMontenegro: 11.2 per 1,000 people, 8.77% of urban populationMongolia: 16.9 per 1,000 people, 17.9% of urban populationMozambique: 37 per 1,000 people, 55% of urban populationMauritania: 34 per 1,000 people, 58.6% of urban populationMauritius: 10.3 per 1,000 people, 48.7% of urban populationMalawi: 31.1 per 1,000 people, 38% of urban populationMalaysia: 12.4 per 1,000 people, 0.2% of urban populationNamibia: 25.9 per 1,000 people, 41.4% of urban populationNiger: 41.4 per 1,000 people, 70.4% of urban populationNigeria: 32.5 per 1,000 people, 48.5% of urban populationNicaragua: 19.1 per 1,000 people, 5.52% of urban populationNetherlands: 9.2 per 1,000 people, 0% of urban populationNorway: 9.7 per 1,000 people, 0% of urban populationNepal: 19 per 1,000 people, 40.1% of urban populationNaoero: 24.6 per 1,000 people, 0.597% of urban populationNew Zealand: 11 per 1,000 people, 0% of urban populationOman: 16.8 per 1,000 people, 0% of urban populationPakistan: 27.4 per 1,000 people, 56% of urban populationPanama: 15.9 per 1,000 people, 16.3% of urban populationPeru: 15.8 per 1,000 people, 45.1% of urban populationPhilippines: 15.9 per 1,000 people, 35.9% of urban populationPalau: 10.7 per 1,000 people, 0.618% of urban populationPapua New Guinea: 24.3 per 1,000 people, 22.3% of urban populationPoland: 6.9 per 1,000 people, 4.22% of urban populationPortugal: 7.9 per 1,000 people, 0.059% of urban populationParaguay: 19.7 per 1,000 people, 15.1% of urban populationWest Bank and Gaza: 26.5 per 1,000 people, 19.5% of urban populationQatar: 9.52 per 1,000 people, 0% of urban populationRomania: 7.5 per 1,000 people, 2.52% of urban populationRussian Federation: 8.4 per 1,000 people, 2.62% of urban populationRwanda: 28.1 per 1,000 people, 38.3% of urban populationSaudi Arabia: 16.5 per 1,000 people, 0.55% of urban populationSudan: 33 per 1,000 people, 73.7% of urban populationSenegal: 29.2 per 1,000 people, 46.4% of urban populationSingapore: 7.4 per 1,000 people, 0% of urban populationSolomon Islands: 26.7 per 1,000 people, 1.95% of urban populationSierra Leone: 30.1 per 1,000 people, 49.3% of urban populationEl Salvador: 15.6 per 1,000 people, 16.5% of urban populationSomalia, Fed. Rep.: 42.3 per 1,000 people, 48.7% of urban populationSerbia: 9.2 per 1,000 people, 1.42% of urban populationSao Tome and Principe: 28.1 per 1,000 people, 82.4% of urban populationSuriname: 17.2 per 1,000 people, 15.8% of urban populationSlovak Republic: 8.5 per 1,000 people, 0.066% of urban populationSlovenia: 7.9 per 1,000 people, 0.527% of urban populationSweden: 9.3 per 1,000 people, 0.336% of urban populationEswatini: 23.6 per 1,000 people, 17% of urban populationSint Maarten (Dutch part): 9.09 per 1,000 people, 2.89% of urban populationSeychelles: 11 per 1,000 people, 48.7% of urban populationSyrian Arab Republic: 23.2 per 1,000 people, 41.1% of urban populationTurks and Caicos Islands: 10.5 per 1,000 people, 0.631% of urban populationChad: 43.3 per 1,000 people, 82% of urban populationTogo: 32.1 per 1,000 people, 38.5% of urban populationThailand: 8.12 per 1,000 people, 2% of urban populationTajikistan: 25.3 per 1,000 people, 0.05% of urban populationTurkmenistan: 20.9 per 1,000 people, 8.38% of urban populationTimor-Leste: 21.8 per 1,000 people, 33.9% of urban populationTonga: 23 per 1,000 people, 0.308% of urban populationTrinidad and Tobago: 10.5 per 1,000 people, 8.63% of urban populationTunisia: 13.4 per 1,000 people, 7.64% of urban populationTurkiye: 11 per 1,000 people, 14.1% of urban populationTuvalu: 22 per 1,000 people, 50.9% of urban populationTanzania: 34.8 per 1,000 people, 70.1% of urban populationUganda: 34.4 per 1,000 people, 52.7% of urban populationUkraine: 5.47 per 1,000 people, 1.1% of urban populationUruguay: 9.8 per 1,000 people, 1.3% of urban populationUnited States: 10.6 per 1,000 people, 0.0932% of urban populationUzbekistan: 25.6 per 1,000 people, 7.1% of urban populationSt. Vincent and the Grenadines: 12 per 1,000 people, 2.76% of urban populationVirgin Islands (U.S.): 11.1 per 1,000 people, 1.1% of urban populationViet Nam: 13.4 per 1,000 people, 32.5% of urban populationVanuatu: 27.7 per 1,000 people, 3.06% of urban populationSamoa: 25 per 1,000 people, 34.6% of urban populationSouth Africa: 18.5 per 1,000 people, 24.2% of urban populationZambia: 32.7 per 1,000 people, 48.3% of urban populationZimbabwe: 29.9 per 1,000 people, 54.9% of urban populationCAFECUITAKORMLIMUSSLBSYCTCDTJKUKRVUT

best-fit line line after adjusting

Four ways to measure the link

MethodrpCountries
Standard (Pearson), not adjusted+0.7806.7e-39184
By rank (Spearman), not adjusted+0.7676.5e-37184
Standard (Pearson), adjusted for national income+0.4117.2e-9184
By rank (Spearman), adjusted for national income+0.3023.3e-5184

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 184 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: +0.369 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from +0.393 (without GNQ) to +0.429 (without MMR). 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: GNQ (-0.019).

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 & Pacific28-0.18
Europe & Central Asia49+0.07
Latin America & Caribbean31+0.45
Middle East, North Africa, Afghanistan & Pakistan21+0.35
Sub-Saharan Africa46+0.40

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 third62+0.51
Middle third61+0.26
Richest third61+0.35

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
Christians106+0.56
Muslims49+0.38

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+0.46
Never a European colony21-0.14
Spain19+0.54
United Kingdom57+0.24

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 = +0.411 after dropping 0 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 23years. 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 = +0.097, 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 birth rate moved did not tend to see their slum share of urban population move with it.

Across countries (adjusted)+0.411for comparison
Within countries+0.380each country vs itself
…and vs the same year elsewhere+0.097q = 0.199 · 174 countries
Year-on-year changes—q = —
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.

1,988 country-years (one country in one year), 174 countries, 2000–2022, about 11 years each on average. Share of the variation that happens within countries over time: 5% for Birth rate, 8% for Slum share of urban population. 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 Slum share of urban population trails Birth rate →lag -10: r = 0.168 (n = 1,309)lag -9: r = 0.164 (n = 1,309)lag -8: r = 0.165 (n = 1,477)lag -7: r = 0.146 (n = 1,477)lag -6: r = 0.154 (n = 1,647)lag -5: r = 0.136 (n = 1,647)lag -4: r = 0.146 (n = 1,810)lag -3: r = 0.129 (n = 1,810)lag -2: r = 0.120 (n = 1,988)lag -1: r = 0.106 (n = 1,988)lag +0: r = 0.097 (n = 1,988)lag +1: r = 0.086 (n = 1,988)lag +2: r = 0.079 (n = 1,988)lag +3: r = 0.075 (n = 1,988)lag +4: r = 0.081 (n = 1,988)lag +5: r = 0.089 (n = 1,988)lag +6: r = 0.095 (n = 1,988)lag +7: r = 0.109 (n = 1,988)lag +8: r = 0.117 (n = 1,988)lag +9: r = 0.140 (n = 1,988)lag +10: r = 0.138 (n = 1,988)

Same year (lag 0): +0.097. 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


per 1,000 people
% of urban population		Years
Central African Republic CAF46.268.9%2024, 2022
Chad TCD43.382%2024, 2022
Somalia, Fed. Rep. SOM42.348.7%2024, 2022
Niger NER41.470.4%2024, 2022
Congo, Dem. Rep. COD40.978.4%2024, 2022
Mali MLI39.592.5%2024, 2022
Angola AGO37.262.7%2024, 2022
Mozambique MOZ3755%2024, 2022
Afghanistan AFG3571.6%2024, 2022
Tanzania TZA34.870.1%2024, 2022
Uganda UGA34.452.7%2024, 2022
Mauritania MRT3458.6%2024, 2022
Benin BEN33.464%2024, 2022
Cameroon CMR33.332.7%2024, 2022
Guinea GIN33.344%2024, 2022

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

Sources

Birth rate

Birth rate, crude (per 1,000 people)

World Bank · CC BY 4.0 · updated quarterly

Slum share of urban population

Population living in slums (% of urban population)

UN-Habitat · CC BY 4.0 · updated quarterly

How this was computed

Data used: most recent value in 2010-2025; values come from 2012–2024. 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 Birth rate and Slum share of urban population

This page shows that two measures go together. It does not show that Birth rate changes Slum share of urban population, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.

More links with Birth rate or Slum share of urban population