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Hampton Gaddy

@hggaddy.bsky.social
2.5K followers 567 following 143 posts

Demographer | Postdoc @magdalenoxford.bsky.social | Assistant Director, callevacentre.org | Usually working on the 1918 flu | he/him | hggaddy.github.io

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Reposted by Hampton Gaddy
Sociology at Oxford @sociologyoxford.bsky.social · 08/10/2026
Remember to join us this Monday for our 1st seminar! Hampton Gaddy @hggaddy.bsky.social will discuss missing data, Indigenous mortality during the 1918 flu, and the Alaskan census 📊
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Hampton Gaddy @hggaddy.bsky.social · 05/10/2026
On 12 October, I'll be giving a seminar at @sociologyoxford.bsky.social. I'll be talking about missing data, Indigenous mortality during the 1918 flu, and the Alaskan census. Reach out if you want a hybrid link! www.sociology.ox.ac.uk/events/missi...
sociology.ox.ac.uk
Missing data and demographic structure obscure the inequality of Alaska Natives in the 1918 influenza pandemic
12.45pm - 2pm
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Hampton Gaddy @hggaddy.bsky.social · 05/10/2026
Really excited to start a postdoc at @magdalenoxford.bsky.social this week! I'll be continuing my (historical) demography research, and also co-running Magdalen's interdisciplinary centre of research excellence (Scroll down if you want to watch me give a talk in Oxford / online next Monday 📢)
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Jenn Dowd @drjenndowd.bsky.social · 28/09/2026
I was also pretty stunned by the wording of this NBER abstract 🫠. As @rcobooth.bsky.social lays out very nicely, there are many important questions to be explored here, but language, especially around reproductive choices, matters. substack.com/home/post/p-... #econsky #demography
substack.com
On prospective grandparents
(a tiresome thing from the internet this weekend, and some new stories)
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Hampton Gaddy @hggaddy.bsky.social · 14/09/2026
Some of the papers will draw on the workshop held at LSE in May (www.lse.ac.uk/Economic-His...), including the long-awaited 1EME many analysts paper. But we're also interested in contributions from anyone with creative methodological perspectives on excess mortality estimation. Get in touch! 👋
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Hampton Gaddy @hggaddy.bsky.social · 14/09/2026
🚨I'm guest editing a special issue of PopStudies with Victoria Knutson, Maarten van Wijhe, José Manuel Aburto, @alysonvanraalte.bsky.social! ‘How do we estimate excess mortality? Current problems and methodological solutions’ Pre-submission enquiries by 1 Dec 2026 CfP: www.lse.ac.uk/internationa...
Call for papers for a special issue of Population Studies – a journal of demography

‘How do we estimate excess mortality? Current problems and methodological solutions’

Guest editors:
Hampton Gaddy (University of Oxford, UK)
Victoria Knutson (University of Washington, USA)
Maarten van Wijhe (Roskilde University, Denmark)
José Manuel Aburto (London School of Hygiene & Tropical Medicine, UK)
Alyson van Raalte (Max Planck Institute for Demographic Research, Germany)

Motivation:

In the last 20 years, excess mortality estimation has become a widespread technique for quantifying the demographic and social impacts of contemporary and historical mortality crises. However, there is surprisingly little systematic methodological work on the topic, and the work that has been published has shown that excess mortality estimates can be highly sensitive to the theoretical and practical foundation of the underlying models, as well as issues of data availability (e.g. Andreasen & Simonsen, 2011; Chandra & Christensen, 2019; Nepomuceno et al., 2022; Duerst & Schöley, 2024; Wakefield & Knutson, 2025). The effect of these issues is that, for example, in the context of its official assessment of the Covid-19 pandemic in Norway, the Norwegian Institute of Public Health declared that there is simply
‘no gold standard for calculating excess mortality’ (Knudsen et al., 2023).

In May 2026, the London School of Economics hosted a two-day workshop, aimed at demonstrating the need for consensus about the use of excess mortality methods and at scoping out the key areas of methodological disagreement (full programme here). One presentation outlined the preliminary results from the ‘One Epidemic, Many Estimates (1EME)’ challenge, in which 22 teams of researchers

[text truncated; continue reading at https://www.lse.ac.uk/international-development/research/population-investigation-committee/Pop-Studies-CfP-How-do-we-estimate-excess-mortality-Current-problems-and-methodological-solutions.pdf]estimation, as well as thoughtful methodological papers that suggest solutions to the outstanding problems and disagreements relating to how to estimate excess mortality.

The descriptive reading of the title will be fulfilled by a series of commissioned articles that speak to the current practice and long history of excess mortality estimation. The guest editors plan for this to include the 1EME paper; an essay by historians of medicine; an essay on the ethics of how (excess) mortality estimation is commonly practised; and a commentary on how excess mortality estimation has been transformed in recent years.

To fulfil the perspective reading of the title, the guest editors are making an open call for contributions relating to the methodology of excess mortality estimation. The objective of the special issue is not to establish a single preferred method for estimating excess mortality—in particular, because different excess mortality analyses have different
explicit or implicit different estimands in mind—but rather to clarify the methodological choices that drive variation in estimates, identify areas of agreement and disagreement, and provide researchers with a clearer framework for selecting and evaluating methods,
conditional on their estimand of interest (see Lundberg et al., 2021). To that end, submissions to the open call should identify a specific methodological question or problem to be addressed; offer an answer or solution to that methodological issue; and outline the conditions under which that approach is valid.

Pre-submission enquiries for submitting to the issue are mandatory and due by 1 December 2026. Enquiries should take the form of a proposed title and abstract, and should be submitted to hampton.gaddy@magd.ox.ac.uk.

[text truncated; continue reading at https://www.lse.ac.uk/international-development/research/population-investigation-committee/Pop-Studies-CfP-How-do-we-estimate-excess-mortality-Current-problems-and-methodological-solutions.pdf]
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Hampton Gaddy @hggaddy.bsky.social · 26/08/2026
This is an extremely well-written open letter from faculty at Ghent. I've heard colleagues privately express uncertainty about what the facts on the ground actually are. I urge everyone to read this letter. The people on the ground have been ringing the alarm bell, and been doing so for months
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Demography - the flagship journal of PAA @readdemography.bsky.social · 14/08/2026
“MSE Workflow for Mortality Analysis”: @thegargiulian.bsky.social presents a workflow for “estimating conflict mortality using multiple heterogeneous & statistically biased lists of victims” & applies it to the 1985-2018 conflict in Colombia. @psglshtm.bsky.social read.dukeupress.edu/demography/a...
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Hampton Gaddy @hggaddy.bsky.social · 04/07/2026
Agreed all around!
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Hampton Gaddy @hggaddy.bsky.social · 02/07/2026
I'm a demographer, so no use in me commenting on that side of things! But here's the previous work that they use to equate NHS spending to QALYs (which they then convert to excess deaths via an unstated methodology) doi.org/10.1016/j.he...
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Hampton Gaddy @hggaddy.bsky.social · 02/07/2026
The politics of the deal really are terrible, but Covid did teach us that we shouldn't throw around oversimplified "excess death" calculations in this way (8/7) bsky.app/profile/theg...
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Hampton Gaddy @hggaddy.bsky.social · 02/07/2026
The drug deal will put strain on the NHS (which they might or might not reprioritise spending to deal with), but it's really difficult to know whether the excess death calculation here is reasonable (especially vs Covid). A ~7% ↑ in deaths per year by 2036 is huge (7/7) bsky.app/profile/andr...
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Hampton Gaddy @hggaddy.bsky.social · 02/07/2026
The ONS' model, like most excess mortality models, implicitly discounts the excess deaths that happened between March 2020 and June 2022 but would've otherwise happened by June 2022. To compare apples with apples, you'd have to add those deaths back in, increasing the Covid number to >137,000 (6/7)
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Hampton Gaddy @hggaddy.bsky.social · 02/07/2026
Another issue is that each death delayed is only postponed temporarily. It's entirely right to ask how many lives the US-UK drug deal will shorten. Every death is a tragedy. But asking that question means the answer can't be compared with the ONS' excess deaths figures for Covid in England (5/7)
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Hampton Gaddy @hggaddy.bsky.social · 02/07/2026
Population ageing matters a lot. It means that more spending is required to delay the average death, because the average person who dies is older. Accounting for this makes the excess death calculation go ↓, and it's hard to say by how much (4/7)
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Hampton Gaddy @hggaddy.bsky.social · 02/07/2026
Population growth means more demand for services, so the extra spending will increase. But the growth (driven by migration) will mostly be at younger ages, where prescriptions are less immediately life-saving. So it's hard to say whether that matters here (3/7)
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Hampton Gaddy @hggaddy.bsky.social · 02/07/2026
The calculation seems to be the extra spending forecast due to the US-UK drug deal x NHS England spending associated with 1 less death in a year = excess deaths per year. And then that figure is summed over 2026-36. But a decade is a really long time window to hold everything constant (2/7)
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Hampton Gaddy @hggaddy.bsky.social · 02/07/2026
I can't make heads or tails of this analysis (in the Guardian today). The methods section is one paragraph. Putting aside assumptions about health econ and NHS decision making, it doesn't seem to consider population growth, ageing, or mortality displacement... (1/7) www.bmj.com/content/394/...
"The population costs of this deal will be the excess deaths that can be avoided if the resources required are not devoted to paying more for new medicines. These are called the “health opportunity costs” (fig 2). They are estimated by combining the published causal estimates with projected NHS expenditure and local mortality data from 2024-25. [ref 16]""Fig 2: Excess deaths from the UK-US pharmaceuticals deal"Front page of the Guardian website: "US-UK drug deal could result in 229,000 excess deaths in England, analysis suggests: Analysis reveals extent of impact on NHS of placating Donald Trump over price of British medicine exports"
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Hampton Gaddy @hggaddy.bsky.social · 24/06/2026
And yes, the UK prime minister figure is supposed to look like Hokusai's tsunami interrupting a sunset 🌊🌅
"The Great Wave off Kanagawa" by Hokusai
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Hampton Gaddy @hggaddy.bsky.social · 24/06/2026
Thanks to all the people who've helped me along the way with this project, especially @ridhikashyap.bsky.social, @demography.bsky.social, @wrigleyfield.bsky.social, @thegargiulian.bsky.social, @appdemography.bsky.social!
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Hampton Gaddy @hggaddy.bsky.social · 24/06/2026
A paper based on my master's thesis is out this morning in PDR! It offers a new way of theorising and estimating "demographic memory". In a week of heatwaves and political instability in the UK, these toy examples work as a nice graphical abstract 🌡️ onlinelibrary.wiley.com/doi/10.1111/...
Figure 2. The estimated annual level of global warming in the Northern Hemisphere from 1900 to 2025, compared to the 1861–90 average (panel a); a Lexis surface of the average memory of global warming from 1900 to 2025, in terms of average experience of warming after age 5 (panel b); population pyramids of Japan and Niger in 2025 with cohorts colored by their average memory of warming in 2025 (panel c); and the average memory of warming in Japan and Niger in 2025 across all cohorts since age 5 (panel d)Figure 3. The proportions of the life of the average British resident lived after age 18 (survivorship memory without individual-level forgetting) under the premiership of Margaret Thatcher, Theresa May, Liz Truss, a male prime minister, an unknown prime minister (from August 2029 onwards), or outside the UK
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Hampton Gaddy @hggaddy.bsky.social · 19/05/2026
I'm going to reference this in a talk on Thursday, so glad to see this out!
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Reposted by Hampton Gaddy
Elizabeth Wrigley-Field @wrigleyfield.bsky.social · 18/05/2026
New research from a team I was part of w Lauren Steele, @andreatilstra.bsky.social, & other virologists & demographers: Research on flu pandemics has been heavily shaped by 1) the 1918 flu & 2) US-specific data for other pandemics. Turns out that way understates the variety of age patterns of risk!
academic.oup.com
Age-specific mortality patterns across influenza pandemics: evidence from all-cause mortality data across multiple populations
AbstractBackground. Understanding age-specific mortality patterns across historic influenza pandemics is crucial for future pandemic preparedness. Prior re
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Hampton Gaddy @hggaddy.bsky.social · 12/05/2026
Looks good to me!
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Hampton Gaddy @hggaddy.bsky.social · 12/05/2026
If you do a little reading group (would love to join!), maybe you should have a silly dress code? "Fancy dress (British sense), formal demography"
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Eric Schneider @ericbschneider.com · 12/05/2026
Really pleased to see our global stunting data up on our world in data. We hope it helps people contextualise child stunting in a much longer historical lens. Thanks to Hannah and Tuna for visualising and explaining the data so well! The link to the original paper is here: doi.org/10.1136/bmjg...
doi.org
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Hampton Gaddy @hggaddy.bsky.social · 01/05/2026
Couldn't have done this without great data (@ipums.bsky.social) and great co-authors (@rebeccasear.bsky.social, @anthrolog.bsky.social)!
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Hampton Gaddy @hggaddy.bsky.social · 06/03/2026
Really exciting!
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Reposted by Hampton Gaddy
Karen Benjamin Guzzo @karenguzzo.bsky.social · 05/03/2026
Glad to see more demographers pushing back against the low fertility panic and in non-demographic outlets, where they might reach broader audiences. 1/ www.nature.com/articles/s41...
nature.com
Low fertility may persist and could be good for the economy - Nature Human Behaviour
Nature Human Behaviour - Low fertility may persist and could be good for the economy
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Reposted by Hampton Gaddy
Eric Schneider @ericbschneider.com · 23/02/2026
In our new paper (BMJ Global Health), we systematically collected 923 historical growth studies covering 122 countries from 1814–2016. By harmonising height-by-age data, we reconstruct stunting patterns over two centuries. Link: doi.org/10.1136/bmjg... 5)
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Hampton Gaddy @hggaddy.bsky.social · 02/02/2026
Come join our workshop on excess mortality methodology! It will be two great days of expert talks, discussion groups, and me revealing the results of our many analyst project! 40+ teams have signed up to estimate 1918 pandemic deaths with the method of their choice -- results should be fascinating!
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Hampton Gaddy @hggaddy.bsky.social · 27/01/2026
Doing a review right now and I'm faced with "X exerts an independent association with Y"
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Evangeline Warren @evangelinewarren.com · 24/01/2026
My research means I spend a lot of timing thinking about the conditions under which people stop trying to preserve their health and well-being. Why do people continue to smoke even when they know the risks of cancer? Why do people refuse to wear a seatbelt or a helmet when they know the risks?
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Demographic Research @demresjournal.bsky.social · 20/01/2026
📣 Call for papers: We are inviting you to submit contributions to a Special Collection on the Socioeconomic Inequalities in Mortality in the Long-Run, organized by K. Thompson, T. Riswick & S. Clouston. Submissions to this collection are possible from January 28, 2026 until June 28, 2026. (1/2)
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Hampton Gaddy @hggaddy.bsky.social · 10/01/2026
My partner has done the Belgian application before, always selected German, and never failed to receive all materials in English 😂
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Hampton Gaddy @hggaddy.bsky.social · 05/01/2026
And for all the 1918 flu cohort studies that compare 1919 to all surrounding cohorts, including 1920, the water is doubly muddied: fertility patterns make it look like any compositional changes persisted into 1920, causing bias in the opposite direction too (2/2) doi.org/10.1080/0032...
doi.org
Did the 1918 influenza pandemic cause a 1920 baby boom? Demographic evidence from neutral Europe
In 1919–20, the European countries that were neutral in the First World War saw a small baby bust followed by a small baby boom. The sparse literature on this topic attributes the 1919 bust to indi...
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Hampton Gaddy @hggaddy.bsky.social · 05/01/2026
Like the authors talk about, this also happened during the 1918 flu, with the 1919 cohort being poorer from birth than (at least in the US). As much as I wish differently, this casts doubt on the whole premise of cohort discontinuity studies of the effects of pandemics! (1/2)
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Jenn Dowd @drjenndowd.bsky.social · 19/12/2025
Fascinating
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Peter Tennant @pwgtennant.bsky.social · 08/12/2025
Thrilled to share my latest paper entitled, "Estimating Discrimination in Sentencing: Distinguishing between Good and Bad Controls" Led by @jpinasanchez.bsky.social, the paper introduces a framework for examining discrimination in criminal justice processes. 🧵 1/10 publicera.kb.se/ejels/articl...
Screenshot of title page including the following abstract:

To minimise confounding bias and disentangle warranted from unwarranted disparities, researchers examining sentencing discrimination have traditionally sought to control for as many legal factors as possible. However, over the past decade, a growing number of scholars have questioned this strategy, noting that many legal factors are themselves subject to judicial discretion and that controlling for them can introduce post-treatment bias. Here, we use directed acyclic graphs (DAGs) to provide a formal and comprehensive assessment of the different types of bias that may arise from different choices of controls. In addition, we propose a new modelling framework to facilitate the selection of controls and reflect the model uncertainty created by the trade-off inherent in judicially-defined legal factors and other factors with a similar dual causal role. We apply this framework to examine race disparities in US federal courts and gender disparities in the England and Wales magistrates’ court. We find substantial model uncertainty for gender disparities and for race disparities affecting Hispanic offenders, rendering estimates of the latter inconclusive. Disparities against black offenders are more consistent and — under specific conditions — could be interpreted as evidence of direct discrimination.
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Rebecca Sear @rebeccasear.bsky.social · 26/11/2025
Retraction Watch has covered the problem of the “national IQ” database. Should be noted I’m far from alone in working to remove these publications. The spreadsheet of pubs which use NIQ - linked to in the article - was started by @kohngregory.bsky.social; a project also worked on by Cathryn Townsend
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Hampton Gaddy @hggaddy.bsky.social · 17/11/2025
The line "excess mortality is often treated like 'data', but ultimately it's a model" is definitely going in the welcome slides for the workshop bsky.app/profile/adam...
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Hampton Gaddy @hggaddy.bsky.social · 17/11/2025
If you want to channel your frustration with bad excess mortality modelling into some productive science, come join our "One Epidemic, Many Estimates" (1EME) project! Sign-ups are welcome through January/February! www.lse.ac.uk/Economic-His...
lse.ac.uk
One epidemic, many estimates (1EME)
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Hampton Gaddy @hggaddy.bsky.social · 17/11/2025
The other part is that populations with polygyny often have strong pro-marriage norms, meaning that marriage markets are more "efficient" at getting men married. There's a nice parallel with China and Japan, re the impact of sex-selective abortion on marriage markets (2/2) bsky.app/profile/hgga...
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Hampton Gaddy @hggaddy.bsky.social · 17/11/2025
Thanks! One part is that marriage markets with polygyny are usually skewed feminine, rather than split 50/50. The biggest reason for this is a ~10 year age gap at marriage meaning that men marry women from larger birth cohorts, plus there are issues of mortality, migration, and preferences (1/2)
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Eric Schneider @ericbschneider.com · 05/11/2025
Curious about using census microdata in your research? 📊 Join us for a webinar on IPUMS International, the world’s leading repository of harmonized census data. 🗓️ 12 Nov 2025 | 🕒 15:15–16:30 UK | 💻 Zoom Register: forms.gle/oqTDNU4Zpn2s... Hosted by the LSE Historical Economic Demography Group.
forms.gle
Register for IPUMs International Online Session
Please use this form to register for the IPUMs International Session hosted by the Historical Economic Demography Group at LSE. The session will be on Zoom from 15:15-16:30 UK Time on 12 November 202...
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Hampton Gaddy @hggaddy.bsky.social · 29/10/2025
That looks right to me! Those results are consistent with our results -- it just depends on how you think about expectations. I wonder what the ratio of F 20-60 / M 30-60 looks like (which would match my framing above better)?
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Hampton Gaddy @hggaddy.bsky.social · 29/10/2025
Plus, in contemporary polygynous populations, men marry women 5-10 years younger on average, so maybe the bands should be shifted from each other. But, cutting the female group off at 45 also means that you treat men who do marry a wife of a similar age as unmarried once they age past 45 (2/2)
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Hampton Gaddy @hggaddy.bsky.social · 29/10/2025
I think that code should work! One question is whether you think that all men 20-60 and all women 20-45 would expect to be married, or whether they just expect to be married at some point in their lives. People who divorce or get widowed can marry single people (1/2)
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Hampton Gaddy @hggaddy.bsky.social · 23/10/2025
Thanks for adding this! I'm curious, are there any papers reporting an adverse causal effect on child health that you're methodologically confident in?
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Hampton Gaddy @hggaddy.bsky.social · 22/10/2025
Happy to talk through the evolutionary implications of the work! We focus a lot on the political science implications in the write up. @rebeccasear.bsky.social might have more thoughts
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