Do Anaemia in women and Electoral democracy go together across countries?

Across 165 countries the link before adjusting for anything is r = -0.53, on a scale from -1 (opposite) to +1 (in step). A version that uses only each country's rank gives -0.57.

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

Comparing each country only with itself across 2000-2023, and setting aside what happened worldwide in each year, the link is -0.098 (171 countries, 4,104 country-years). Using year-to-year changes, it is -0.031.

Does Anaemia in women cause Electoral democracy?

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.

Anaemia in women vs. Electoral democracy

Holds up after adjusting for income

Across 165 countries, Anaemia in women and Electoral democracy rise and fall together at r = -0.53 (on a scale from −1 to +1, where 0 means no link). Comparing only countries with similar income (GDP per person) shrinks it to -0.32 (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 electoral democracy, 0.259 to 0.741 points, anaemia in women is better by 10.9% of women aged 15-49 at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 5.51% of women aged 15-49.

Link before adjusting (r)-0.531p = 2.1e-13 · 165 countries

After adjusting for national income-0.320p = 3.0e-5 · likely range [-0.45, -0.17]

p, allowing for regions0.086standard error 0.156 · 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.

Anaemia in women · % of women aged 15-49link with income -0.67 · high

Electoral democracy · index (0-1)link with income +0.49 · moderate

“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	-0.531	2.1e-13	165
By rank (Spearman), not adjusted	-0.566	2.4e-15	165
Standard (Pearson), adjusted for national income	-0.320	3.0e-5	165
By rank (Spearman), adjusted for national income	-0.342	7.6e-6	165

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 165 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: +0.212 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from -0.341 (without CHN) to -0.297 (without BHR). 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: BHR (+0.023).

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	20	-0.25
Europe & Central Asia	48	-0.51
Latin America & Caribbean	22	-0.34
Middle East, North Africa, Afghanistan & Pakistan	21	-0.46
Sub-Saharan Africa	46	-0.17

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	55	-0.15
Middle third	55	-0.23
Richest third	55	-0.65

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	98	-0.24
Muslims	47	+0.10

By last european coloniser

	n	r
France	25	+0.20
Never a European colony	21	-0.32
Spain	18	-0.45
United Kingdom	49	-0.42

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 = -0.312 after dropping 1 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 24years. 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 = -0.098, 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 anaemia in women moved did not tend to see their electoral democracy move with it.

Across countries (adjusted)-0.320for comparison

Within countries-0.166each country vs itself

…and vs the same year elsewhere-0.098q = 0.186 · 171 countries

Year-on-year changes-0.031q = 0.265

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.

4,104 country-years (one country in one year), 171 countries, 2000–2023, about 24 years each on average. Share of the variation that happens within countries over time: 7% for Anaemia in women, 3% for Electoral democracy. 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): -0.098. 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 women aged 15-49	index (0-1)	Years
Gabon GAB	59.9%	0.302	2023, 2025
Mali MLI	56.5%	0.164	2023, 2025
Mauritania MRT	54.5%	0.328	2023, 2025
India IND	53.7%	0.377	2023, 2025
Cote d'Ivoire CIV	51.4%	0.394	2023, 2025
Benin BEN	50%	0.493	2023, 2025
Niger NER	47.1%	0.227	2023, 2025
Mozambique MOZ	47%	0.279	2023, 2025
Congo, Rep. COG	46.7%	0.243	2023, 2025
Chad TCD	46.5%	0.242	2023, 2025
Pakistan PAK	46.5%	0.302	2023, 2025
Somalia, Fed. Rep. SOM	46.2%	0.165	2023, 2025
Gambia, The GMB	46.1%	0.641	2023, 2025
Haiti HTI	45.9%	0.238	2023, 2025
Guinea-Bissau GNB	45.7%	0.252	2023, 2025

World Bank, World Development Indicators
Coppedge, M. et al., V-Dem Dataset, Varieties of Democracy (V-Dem) Project

Sources

Anaemia in women

Prevalence of anaemia among women of reproductive age (% of women ages 15-49)

World Health Organization · CC BY 4.0 · updated quarterly

Electoral democracy

Electoral democracy index (polyarchy)

V-Dem Institute, University of Gothenburg · via Our World in Data · CC BY 4.0 · updated annual

Based on political scientist Robert Dahl's idea of "polyarchy": are leaders chosen in free and fair elections, with freedom of speech, freedom to form groups, and the vote for nearly all adults? It is the base index that most other V-Dem measures are built on.

How this was computed

Data used: most recent value in 2010-2025; values come from 2023–2025. 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 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 Anaemia in women and Electoral democracy

This page shows that two measures go together. It does not show that Anaemia in women changes Electoral democracy, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.