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Reposted by Hampton Gaddy

Antonino Polizzi @polizzan.bsky.social · 1d

✍️ Just out: Annette Baudisch & I delve into the formal demography of fertility, birth, & reproduction timing. 👶 We use methods from mortality research to summarize when in the parental life course children are born. 📆 1/n
doi.org/10.1080/0032...
@sdu.dk @oxforddemsci.bsky.social @mpidr.bsky.social

Fertility, birth, reproduction: Connecting formal demographic frameworks

The conventional framework of fertility research conceptualizes childbirth from the mother’s perspective. From her perspective, birth is an uncertain and potentially recurring event. In contrast, t...

doi.org

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Reposted by Hampton Gaddy

tom westland @tomwestland.bsky.social · 22h

CALL FOR PAPERS
A workshop at LSE next April on 'Uses and Abuses of the Murdock Atlas in Social Science Research'. We're looking for cross-disciplinary engagement to think critically about what this widely used source means, what it can & can't tell us. Submit by Nov 14
www.lse.ac.uk/economic-his...

Uses and abuses of the Murdock Atlas in social science research

www.lse.ac.uk

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Reposted by Hampton Gaddy

Cameron D. Campbell 康文林 @camerondcampbell.blog · 1d

I'd add that at least in China before the 20th century, polygyny probably wasn't as prevalent as commonly imagined. In our northeast Chinese rural datasets, it was very rare. By the late 19th century, it was also uncommon in the Imperial Lineage, except among close relatives of the Emperor. 1/3

Hampton Gaddy @hggaddy.bsky.social · 2d

🚨 The Economist has been telling you for years that polygamy causes civil war by locking men out of marriage. A new article with @rebeccasear.bsky.social and @anthrolog.bsky.social explains that the demography of marriage markets doesn't actually work that way. 🧵

www.pnas.org/doi/10.1073/...

High rates of polygyny do not lock large proportions of men out of the marriage market | PNAS

There is a widespread belief, in both the scholarly literature and the popular press, that polygyny prevents large numbers of men from marrying by ...

www.pnas.org

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Hampton Gaddy @hggaddy.bsky.social · 1d

One of the polygyny → bad outcomes papers jumps through hoops to justify China as polygynous, inferring from TFR in 1950 (bad idea) that ~7% of men practised it and saying that polygyny since time immemorial shaped contemporary institutions anyways (doubtful, I guess?) (2/2)

doi.org/10.1017/ssh....

Polygamy, the Commodification of Women, and Underdevelopment | Social Science History | Cambridge Core

Polygamy, the Commodification of Women, and Underdevelopment - Volume 46 Issue 1

doi.org

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Hampton Gaddy @hggaddy.bsky.social · 1d

That's so interesting (and typical, I guess). The meme of men thinking about the Roman Empire comes to mind (1/2)

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Reposted by Hampton Gaddy

Hampton Gaddy @hggaddy.bsky.social · 2d

🚨 The Economist has been telling you for years that polygamy causes civil war by locking men out of marriage. A new article with @rebeccasear.bsky.social and @anthrolog.bsky.social explains that the demography of marriage markets doesn't actually work that way. 🧵

www.pnas.org/doi/10.1073/...

High rates of polygyny do not lock large proportions of men out of the marriage market | PNAS

There is a widespread belief, in both the scholarly literature and the popular press, that polygyny prevents large numbers of men from marrying by ...

www.pnas.org

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Hampton Gaddy @hggaddy.bsky.social · 2d

Thanks!

Hampton Gaddy @hggaddy.bsky.social · 2d

The demography is tricky for sure! And thanks! We took some direct inspiration from your work trying to debunk "if parent marry, child won't suffer poverty" arguments (referenced in the conclusion)

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Hampton Gaddy @hggaddy.bsky.social · 2d

Can't wait! @ericbschneider.bsky.social and I are reading it for a journal club in the department early in the new year :)

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Reposted by Hampton Gaddy

Centre for Culture and Evolution @brunelcce.bsky.social · 2d

🧵 1/ New paper from CCEs @rebeccasear.bsky.social led by @hggaddy.bsky.social with @anthrolog.bsky.social challenging some common assumptions about polygyny (there are many…)

it's open access 🔓 🧪 @brunelpsy.bsky.social

High rates of polygyny do not lock large proportions of men out of the marriage market

www.pnas.org

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Hampton Gaddy @hggaddy.bsky.social · 2d

This work has been a long time coming! Thanks to all the brilliant demographers, evolutionary scholars, and economic historians who have given us feedback over the last few years, especially at @oxforddemsci.bsky.social @lseechist.bsky.social @ehbea.bsky.social @bspsuk.bsky.social! 🥳 (14/14)

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Hampton Gaddy @hggaddy.bsky.social · 2d

Even though the demography is clear, the idea that polygamy is unsustainable and is the root of male-vs-male violence is super influential in political science, incel groups (⚠️), and theories about the evolution of monogamy. In the article, we talk through all three sets of discourse (13/14)

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Hampton Gaddy @hggaddy.bsky.social · 2d

But reality is more complicated! Sex-selective abortion is abhorrent, but its marriage market impact isn't large. Taiwan and Japan have ~4x higher rates of unmarried men than China, because the social pressure to marry in China is broadly higher (12/14)

www.demographic-research.org/articles/vol...

Figure 4 in https://www.demographic-research.org/articles/volume/43/46. Estimated proportions of never-married people by age 45‒49 from 2010 to 2050 by applying constant contemporary forces of attraction by age-only, α_ij (solid line), and by age and education, α_ijkl (dashed line), to population projections in four East Asian societies.

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Hampton Gaddy @hggaddy.bsky.social · 2d

There's precedent for this whole argument in the "bare branches" literature! Political scientists have argued that sex-selective abortion in China skews marriage markets, creating a generation of unmarried dangerous young men. Cue the Economist again. (11/14)

www.economist.com/asia/2015/04...

Bare branches, redundant males

Distorted sex ratios at birth a generation ago are changing marriage and damaging societies in Asia’s twin giants

www.economist.com

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Hampton Gaddy @hggaddy.bsky.social · 2d

So what's the story here? High-polygamy communities like rural West Africa (and Utah in 1880) have strong pro-marriage norms. Polygamy reduces men's ability to marry in theory, but these norms seem to override that effect, meaning that men marry more in places with polygamy, not less! (10/14)

A simple diagram showing that polygamy and strong marriage norms co-occur, and then strong marriage norms increase the rate of men marrying more than polygamy decreases it

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Hampton Gaddy @hggaddy.bsky.social · 2d

Data from the US in 1880 show the same pattern. Counties with Mormon polygamy usually have lower rates of young men who've never married, especially vs. other counties in the West. And this holds even after controlling for sex ratios: it's not just that polygamy happens in feminine places (9/14)

Figure 3 in https://www.pnas.org/doi/10.1073/pnas.2508091122. Full distributions, medians, and quartiles of the proportion of men in their 20s who have never been married, across 2,475 US counties as recorded in the 1880 federal census. The counties are disaggregated by the combination of region and the presence or absence of Mormon polygyny.

Figure S9 in https://www.pnas.org/doi/10.1073/pnas.2508091122. Proportion of men in their 20s who had never married across 2,475 US counties in 1880, disaggregated by the presence or absence of Mormon polygyny, against the ratio of men in their 20s to women in their 20s. Only counties with more than 100 men over age 20 enumerated in the census are shown. The black line is the moving average (period = 250) of the prevalence of unmarried men for the counties without Mormon polygyny, conditional on the population sex ratio.

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Hampton Gaddy @hggaddy.bsky.social · 2d

The global census data show that, within countries, communities with more polygamy usually have *fewer* unmarried men! This is the pattern in 50% of countries, while in another 43% there is no relationship. Polygamy being associated with unmarried men is the exception, not the rule (8/14)

Figure 2 in https://www.pnas.org/doi/10.1073/pnas.2508091122. (Panel A) Subnational associations between the proportion of married men over age 20 who are in a polygynous marriage and the proportion of men in their 20s who have never been married, in a representative selection of 18 of 74 censuses in the sample, under the main model specification. (Panel B) Standardized coefficient (β) and 95% CI of the association in A for each of the 74 censuses in the sample, under the main model specification. The statistical significance of the coefficients shown is adjusted for multiple comparisons within the entire multiverse of tests in SI Appendix, Fig. S8; the CI shown are unadjusted.

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Hampton Gaddy @hggaddy.bsky.social · 2d

Then we look at the real world using census data from @ipums.bsky.social. Our data covers 30 countries in Africa, Asia, and Oceania that practice polygamy, plus historical data from the 1880 census of the US, allowing us to look at Utah in the era of Mormon polygamy (7/14)

The homepage of IPUMS International (https://international.ipums.org/international/)

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Hampton Gaddy @hggaddy.bsky.social · 2d

To start with, we show the number of men and women in a marriage market usually isn't equal. At the extreme, when mortality is high, women outlive men, men marry younger women, and the population is growing, 50% of men can marry 2.5 women each, "leaving" 1 wife for the other 50% of men (6/14)

Figure 1 in https://www.pnas.org/doi/10.1073/pnas.2508091122. Results from a demographic model of the maximum proportion of men who can be married to 2.5 wives on average, such that all other men of the same age can marry one wife, under a stable population regime that is closed to migration, as a function of female (e0,f) and male (e0,m) life expectancy, the annual population growth rate (r), male age (p), and the age gap between spouses (g)

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Hampton Gaddy @hggaddy.bsky.social · 2d

The idea also came to fame in a 2012 paper by evolutionary psychologist Joe Henrich. But Kanazawa and Henrich only use simple demographic thought experiments and cross-national comparisons to make their argument. What does more detailed data say? (5/14)

royalsocietypublishing.org/doi/10.1098/...

The puzzle of monogamous marriage | Philosophical Transactions of the Royal Society B: Biological Sciences

The anthropological record indicates that approximately 85 per cent of human societies have permitted men to have more than one wife (polygynous marriage), and both empirical and evolutionary consider...

royalsocietypublishing.org

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Hampton Gaddy @hggaddy.bsky.social · 2d

This idea became wildly popular because of a 2009 study by Satoshi Kanazawa (www.journals.uchicago.edu/doi/10.1017/...), who has a long history of pseudoscientific and explicitly racist views (4/14)

www.bbc.co.uk/news/uk-1345...

LSE investigates lecturer's blog over race row

The London School of Economics investigates a blog by one of its lecturers, Satoshi Kanazawa, which sparked anger by discussing

www.bbc.co.uk

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Hampton Gaddy @hggaddy.bsky.social · 2d

Despite polygamy being so common, political science research has argued that it's massively destructive for societies. The simple thinking is that if one man marries two women, another man must go unmarried → creating large pools of angry unmarried men (3/14)

www.economist.com/the-economis...

Why polygamy breeds civil war

When large numbers of men are doomed to bachelorhood, they get desperate

www.economist.com

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Hampton Gaddy @hggaddy.bsky.social · 2d

Polygamy has been widespread throughout history and remains common throughout the world. It's less prevalent than in the past, but a significant share of women and children in many Sub-Saharan African countries still live in polygynous households (2/14)

www.demographic-research.org/articles/vol...

Demographic Research - Children under 5 in polygynous households in sub-Saharan Africa, 2000 to 2020 (Volume 51 - Article 32 | Pages 999–1016)

Volume 51 - Article 32 | Pages 999–1016

www.demographic-research.org

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Hampton Gaddy @hggaddy.bsky.social · 2d

🚨 The Economist has been telling you for years that polygamy causes civil war by locking men out of marriage. A new article with @rebeccasear.bsky.social and @anthrolog.bsky.social explains that the demography of marriage markets doesn't actually work that way. 🧵

www.pnas.org/doi/10.1073/...

High rates of polygyny do not lock large proportions of men out of the marriage market | PNAS

There is a widespread belief, in both the scholarly literature and the popular press, that polygyny prevents large numbers of men from marrying by ...

www.pnas.org

3 48 120

Hampton Gaddy @hggaddy.bsky.social · 12d

LSE and @bspsuk.bsky.social are hosting a workshop on "Being an academic in population studies" on 3 November! It'll be a nice mix of methods training and career advice with great talks by @ericbschneider.bsky.social, Wendy Sigle, José Manuel Aburto, and others!

www.eventbrite.co.uk/e/being-an-a...

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