Do Adult literacy and Maternal mortality go together across countries?

Across 132 countries the link before adjusting for anything is r = -0.74, on a scale from -1 (opposite) to +1 (in step). A version that uses only each country's rank gives -0.77.

Does the link hold within countries over time, not just across countries?

Comparing each country only with itself across 1990-2023, and setting aside what happened worldwide in each year, the link is -0.406 (78 countries, 772 country-years). Using year-to-year changes, it is -0.187.

Does Adult literacy cause Maternal mortality?

This analysis cannot answer that. It shows only that the two go together. A link between two country measures, adjusted or not, does not show that either one changes the other. Country figures also say nothing about individual people.

Adult literacy vs. Maternal mortality

Holds up after adjusting for income

Across 132 countries, Adult literacy and Maternal mortality 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 -0.49 (q = 0.0032, 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.

Comparing countries across the middle half of adult literacy, 74.2% to 97.8% of adults, maternal mortality is better by 176 per 100,000 live births at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 118 per 100,000 live births.

Link before adjusting (r)-0.741p = 2.9e-24 · 132 countries

After adjusting for national income-0.485p = 4.2e-9 · likely range [-0.61, -0.34]

p, allowing for regions4.8e-5standard error 0.037 · 6 regions

Check for luck (q)0.003across 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.

Adult literacy · % of adultslink with income +0.73 · high

Maternal mortality · per 100,000 live birthslink with income -0.85 · 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

best-fit line line after adjusting

Four ways to measure the link

Method	r	p	Countries
Standard (Pearson), not adjusted	-0.741	2.9e-24	132
By rank (Spearman), not adjusted	-0.766	9.3e-27	132
Standard (Pearson), adjusted for national income	-0.485	4.2e-9	132
By rank (Spearman), adjusted for national income	-0.412	1.0e-6	132

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 132 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: +0.256 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from -0.538 (without NGA) to -0.444 (without TCD). 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: NGA (-0.052).

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.

	n	r
East Asia & Pacific	22	-0.15
Europe & Central Asia	23	-0.00
Latin America & Caribbean	22	-0.60
Middle East, North Africa, Afghanistan & Pakistan	18	-0.80
Sub-Saharan Africa	41	-0.35

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.

	n	r
Poorest third	44	-0.54
Middle third	44	-0.24
Richest third	44	-0.61

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.

	n	r
Christians	71	-0.48
Muslims	42	-0.51

By last european coloniser

	n	r
France	22	-0.58
Never a European colony	16	-0.43
Spain	18	+0.07
United Kingdom	42	-0.27

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 = -0.416 after dropping 12 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 34years. 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 = -0.406) but mostly disappears in year-to-year changes (r = -0.187). That points to slow trends particular to each country, not the two measures moving together from year to year.

Across countries (adjusted)-0.485for comparison

Within countries-0.650each country vs itself

…and vs the same year elsewhere-0.406q = 0.000 · 78 countries

Year-on-year changes-0.187q = 0.231

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.
The association is much weaker in year-on-year changes than in levels, which points to shared country-specific trends.

772 country-years (one country in one year), 78 countries, 1990–2023, about 10 years each on average. Share of the variation that happens within countries over time: 7% for Adult literacy, 18% for Maternal mortality. 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

Same year (lag 0): -0.406. 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 largest value on this curve (-0.50 at lag +7) is higher than the same-year one by 0.10. That gap is not a finding. It is the largest of 21 closely related estimates, and picking the biggest of many tests always makes it look bigger. That is exactly why nothing on this site is ranked or chosen by lag.

The data

	% of adults	per 100,000 live births	Years
Uzbekistan UZB	100%	26	2022, 2023
Tuvalu TUV	100%	170	2022, 2023
Russian Federation RUS	99.9%	9	2021, 2023
San Marino SMR	99.9%	8	2022, 2023
Turkmenistan TKM	99.9%	5	2022, 2023
Latvia LVA	99.9%	19	2011, 2023
Estonia EST	99.9%	5	2011, 2023
Belarus BLR	99.9%	1	2019, 2023
Palau PLW	99.8%	89	2020, 2023
Armenia ARM	99.8%	19	2023
Lithuania LTU	99.8%	8	2011, 2023
Azerbaijan AZE	99.8%	18	2023
Spain ESP	99.7%	3	2021, 2023
Georgia GEO	99.7%	20	2024, 2023
Tonga TON	99.5%	67	2023

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

Sources

Adult literacy

Literacy rate, adult total (% of people ages 15 and above)

UNESCO Institute for Statistics · CC BY 4.0 · updated quarterly

Reported only in census or survey years for most countries, so the data are sparse and uneven rather than yearly.

Maternal mortality

Maternal mortality ratio, modelled estimate (per 100,000 live births)

WHO and the UN Maternal Mortality Estimation Inter-Agency Group · CC BY 4.0 · updated quarterly

Estimated with a model, like stunting, and for the same reason. Deaths in childbirth are rare in small countries with weak death records, so the agencies estimate rather than count.

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 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 Adult literacy and Maternal mortality

This page shows that two measures go together. It does not show that Adult literacy changes Maternal mortality, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.