Capital per worker vs. Women's age at first marriage
Holds up after adjusting for income
Across 40 countries, Capital per worker and Women's age at first marriage rise and fall together at r = +0.72 (on a scale from −1 to +1, where 0 means no link). It holds up almost unchanged when only countries with similar income (GDP per person) are compared (r = +0.63, q = 0.018, allowing for the many pairs tested).
Comparing countries across the middle half of women's age at first marriage, 28.9 to 32 years, capital per worker is $175,793 higher at the top of that range than the bottom. Comparing only countries with similar national income, the gap is $123,195.
Link before adjusting (r)+0.722p = 1.5e-7 · 40 countries
After adjusting for national income+0.628p = 1.9e-5 · likely range [+0.39, +0.79]
p, allowing for regions0.001standard error 0.066 · 5 regions
Check for luck (q)0.018across 18,622 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.
Capital per worker · 2021 international $ per workerlink with income +0.93 · proxy
Women's age at first marriage · yearslink with income +0.53 · 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 | +0.722 | 1.5e-7 | 40 |
| By rank (Spearman), not adjusted | +0.775 | 4.5e-9 | 40 |
| Standard (Pearson), adjusted for national income | +0.628 | 1.9e-5 | 40 |
| By rank (Spearman), adjusted for national income | +0.669 | 3.3e-6 | 40 |
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 40 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: +0.094 (a minus sign means it grew).
How solid is it?
Leaving out one country at a time, r ranges from +0.598 (without ITA) to +0.665 (without CHL). 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: CHL (+0.037).
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 | ||
|---|---|---|---|
| Europe & Central Asia | 30 | +0.65 |
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 | 14 | +0.60 | |
| Middle third | 13 | +0.81 | |
| Richest third | 13 | +0.53 |
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 | 33 | +0.64 |
By official ideology
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 | ||
|---|---|---|---|
| No strong official ideology | 36 | +0.63 |
By party system
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 | ||
|---|---|---|---|
| No parties banned | 39 | +0.62 |
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 = +0.628 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 21years. 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 = +0.347) but mostly disappears in year-to-year changes (r = +0.051). That points to slow trends particular to each country, not the two measures moving together from year to year.
Across countries (adjusted)+0.628for comparison
Within countries+0.857each country vs itself
…and vs the same year elsewhere+0.347q = 0.025 · 41 countries
Year-on-year changes+0.051q = 0.544
Read with care.
- 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.
693 country-years (one country in one year), 41 countries, 2001–2021, about 17 years each on average. Share of the variation that happens within countries over time: 28% for Capital per worker, 35% for Women's age at first marriage. 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): +0.347. 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 (+0.42 at lag +6) is higher than the same-year one by 0.07. 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
2021 international $ per worker | years | Years | |
|---|---|---|---|
| Ireland IRL | $916,129 | 31.9 | 2023, 2016 |
| Belgium BEL | $788,016 | 32 | 2023, 2020 |
| Italy ITA | $772,186 | 33.6 | 2023, 2020 |
| Norway NOR | $771,357 | 34.1 | 2023, 2020 |
| Switzerland CHE | $713,606 | 30.9 | 2023, 2020 |
| France FRA | $697,343 | 33.1 | 2023, 2018 |
| Austria AUT | $691,757 | 32 | 2023, 2019 |
| Finland FIN | $666,233 | 31.9 | 2023, 2019 |
| Iceland ISL | $663,692 | 32.4 | 2023, 2011 |
| Spain ESP | $645,774 | 34.9 | 2023, 2020 |
| Luxembourg LUX | $630,742 | 32.1 | 2023, 2019 |
| Denmark DNK | $624,134 | 33 | 2023, 2020 |
| Australia AUS | $588,436 | 29.2 | 2023, 2020 |
| Sweden SWE | $568,885 | 34.8 | 2023, 2020 |
| Latvia LVA | $567,433 | 29.8 | 2023, 2020 |
Feenstra, Robert C., Robert Inklaar and Marcel P. Timmer (2015), "The Next Generation of the Penn World Table", American Economic Review, 105(10), 3150-3182, www.ggdc.net/pwt. Data: Penn World Table version 11.0, Groningen Growth and Development Centre, doi:10.34894/FABVLR.
OECD databases as named on each indicator: PISA, Social Expenditure Database (SOCX), Income Distribution Database, Development Assistance Committee statistics, Family Database, Government at a Glance, Corporate Tax Statistics, employment and environment statistics
Sources
Capital per worker
Capital stock per person engaged, at current PPPs (Penn World Table)
Groningen Growth and Development Centre, University of Groningen · via DataverseNL · CC BY 4.0 · updated irregular (new versions every few years)
The value of a country's buildings, machines, roads and other equipment, divided by the number of people working. It is in dollars adjusted for what money buys in each country, and it is best for comparing countries in the same year. The Penn World Table builds it by adding up past investment and taking off wear and tear, so it is linked to the investment share by construction. Where it is used for adjusting, it is measured in percentage terms (on a log scale), like income. No "better" direction is set.
Women's age at first marriage
Mean age of women at first marriage
OECD · via Our World in Data · CC BY 4.0 (OECD terms and conditions) · updated annual, except the snapshots noted per indicator
Published from 2001. How many countries report it varies from year to year: 25 in 2012, two in 2021. So the latest value in the time window used is from a different year for different countries. No "better" direction is set.
How this was computed
Data used: most recent value in 2010-2025; values come from 2011–2023. 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 5 World Bank regions. The q-value corrects for testing all 18,622 pairs at once, using the Benjamini–Hochberg method. Underlying data last updated V-Dem v16; V-Party v2. How the country data works · explore Capital per worker and Women's age at first marriage
This page shows that two measures go together. It does not show that Capital per worker changes Women's age at first marriage, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.
More links with Capital per worker or Women's age at first marriage
- Voice and accountability vs Women's age at first marriage before +0.70 → after adjusting +0.59
- Gender score vs Women's age at first marriage before +0.56 → after adjusting +0.54
- Liberal democracy vs Women's age at first marriage before +0.64 → after adjusting +0.52
- Political rights (FH) vs Women's age at first marriage before -0.61 → after adjusting -0.51
- Civil liberties (FH) vs Women's age at first marriage before -0.61 → after adjusting -0.50
- Governance score vs Women's age at first marriage before +0.63 → after adjusting +0.50
- Women in parliament vs Women's age at first marriage before +0.51 → after adjusting +0.49
- Primary enrollment vs Women's age at first marriage before +0.41 → after adjusting +0.48