Florian Foos

The effects of Facebook and Instagram political advertisements on the 2020 US election Nature Human Behaviour, Published online: 05 March 2026; doi:10.1038/s41562-025-02329-9To study the effects of political advertising, we conducted a field experiment with over 60,000 participants. Removing political advertisements from the Facebook and Instagram feeds of randomly selected participants before the 2020 US election did not have a detectable effect on political knowledge, polarization, turnout or political participation.

The effects of Facebook and Instagram political advertisements on the 2020 US election

This will be the 3rd edition. If you study pol. behaviour and work on #CEE, this is the right place to present your research. Dates: June 25-26. Discussants include @simonhix.bsky.social & @eliasdinas.bsky.social. Highlight: roundtable on dem. erosion with H. Kriesi, M. Svolik & N. Wunsch.

EPSS Travel Grants for 2026 Belfast conference:

PhD students & junior scholars @ institutions in European countries that are often underrepresented, can apply for full fee waiver & £500 stipend

Apply: lnkd.in/ehXjhCgf
Deadline: March 8, 11:59pm GMT.

More details: lnkd.in/eZTP5sWR

📢 Call for papers!

We are organizing the 6th Early Career Workshop in Quantitative Political Economy on 14-15 May 2026 at King’s College London!

Keynote: Shanker Satyanath (NYU)

No fee, travel grants might become available!

Submit at: tinyurl.com/qpe2026

Science communication has never been more important.

In this animation, @yamilrvelez.bsky.social, Donald Green and I break down our research exploring whether AI chatbots can increase political engagement among young, politically unaligned voters.

Link to animation: www.youtube.com/watch?v=iCuX...

It's normal to think that this won't work in the UK, but governments with big majorities have not been working well either.

and on Labour politicians (not voters!) hating the Greens. The question is what will happen if Labour get decimated badly at GE. A government relying on support from the SNP and Plaid wouldn't be too crazy imo. Eg Sanchez managed to negotiate a compromise with Catalan nationalists for their support

Tbh, Polanski looks flexible enough to me that there will be a whipping system if they need one, even if they won't call it that. Other countries have managed to keep majorities of one vote together (especially if the far right is the alternative). But I obviously agree on the inexperience..

Yes and yes..

Spain would be an obvious example, where the socialist government has relied on small regional parties to give them a majority.

Why would that necessarily be a disaster? Multi-party coalitions work well enough in many other countries..

YouGov has the Greens in second place for the first time

Also Starmer (and Badenoch, but no surprise there) adopting Goodwin's "sectarianism" framing.. ugly stuff.

For colleagues in the London area: next week (6-7 March), we're hosting the annual LSE Behavioural Political Economy Workshop at @lsegovernment.bsky.social together with @florianfoos.bsky.social and @thchau.bsky.social. If you'd like to come, please sign up here: forms.cloud.microsoft/e/uxaAx17DHq

"Extremes of the left" ... Spencer didn't sound extreme to me (and I doubt she sounded extreme to most observers). Instead of insulting her and her party, Labour would do well asking themselves, why someone as talented and interesting as Spencer isn't standing for Labour.

Great new paper in The Review of Economic Studies using randomized incentives to detect non-response bias, using administrative data to provide ground truth for comparison. While incentives increased participation, they didn't reliably reduce NR bias

academic.oup.com/restud/advan...

You are interested in survey experiments or plan to do your own (first) survey experiment?

I offer a class at @methodsnet.bsky.social in Vienna this summer (6 - 10 July) that might be interesting for you! 👇

methodsnet.org/course/d10-d...

Great PhD position with the amazing @dianebolet.bsky.social in her ERC project. Apply!

Building 👏 more 👏 housing 👏 reduces 👏 housing 👏 prices 👏

Even when the new housing is more expensive, it lowers the cost of the pre-existing housing, as richer people move out of older housing into the new ones.

Political campaigns worldwide experiment with AI. But how do people see different electoral uses of AI and with what consequences?

In a new study in @polcommjournal.bsky.social with @adrauc.bsky.social and @kunkakom.bsky.social, we address these questions. www.tandfonline.com/doi/full/10.... 1/

February’s JOP Article of the Month asks if campaign donors are simply affluent people who happen to give to campaigns, or if donors and the affluent differ in their policy views. #JOP #PoliticalScience #Donors #Policy #Affluence @thejop.bsky.social www.journals.uchicago.edu/doi/10.1086/...

The Apprentice's Sorcerer Or I how I learned to start worrying and love Claude Code

🤖NEW POST ON AI🤖

Perhaps you're thinking like Brenda from Bristol, 'not another one!' but... I felt that lots of writing about Claude Code doesn't really show you how it works. So I thought well, why not? And along the way some bad literary allusions. 1/n

benansell.substack.com/p/the-appren...

The @lsegovernment.bsky.social Political Behaviour Seminar continues today at 4pm GMT with @sirianned.bsky.social presenting “Elites as Democratic Gatekeepers”. Join us in London or on Zoom, co-organised with @sarahobolt.bsky.social, @florianfoos.bsky.social & @mathiaspoertner.bsky.social ✍️

Today at 4pm GMT: @thchau.bsky.social is presenting "More than Tolerance" at the @lsegovernment.bsky.social Political Behaviour Seminar, organised together with @sarahobolt.bsky.social, @florianfoos.bsky.social & @mathiaspoertner.bsky.social. Join us in London or on Zoom!

🚨📄 New paper (conditional accepted at @thejop.bsky.social):

We test whether social desirability bias actually distorts answers in online surveys.

Short version:
It mostly doesn’t.

w. @timallinger.bsky.social @kristianvsf.bsky.social @morganlcj.bsky.social

URL: osf.io/preprints/os...

IN NEW ISSUE: How do UK political elites reconcile with a low trust environment? @chrisbutlerpol.bsky.social, @drjennings.bsky.social & Gerry Stoker examine this question in @polstudies.bsky.social: buff.ly/3E6DkuS (OPEN ACCESS)

@polstudiesassoc.bsky.social @uoypolitics.bsky.social #polsky

It must be very hard to publish null results Publication practices in the social sciences act as a filter that favors statistically significant results over null findings. While the problem of selection on significance (SoS) is well-known in theory, it has been difficult to measure its scope empirically, and it has been challenging to determine how selection varies across contexts. In this article, we use large language models to extract granular and validated data on about 100,000 articles published in over 150 political science journals from 2010 to 2024. We show that fewer than 2% of articles that rely on statistical methods report null-only findings in their abstracts, while over 90% of papers highlight significant results. To put these findings in perspective, we develop and calibrate a simple model of publication bias. Across a range of plausible assumptions, we find that statistically significant results are estimated to be one to two orders of magnitude more likely to enter the published record than null results. Leveraging metadata extracted from individual articles, we show that the pattern of strong SoS holds across subfields, journals, methods, and time periods. However, a few factors such as pre-registration and randomized experiments correlate with greater acceptance of null results. We conclude by discussing implications for the field and the potential of our new dataset for investigating other questions about political science.

I have a new paper. We look at ~all stats articles in political science post-2010 & show that 94% have abstracts that claim to reject a null. Only 2% present only null results. This is hard to explain unless the research process has a filter that only lets rejections through.

We’ve just released the Youth Wing Membership Survey (YOUMEM) dataset:
dataverse.harvard.edu/dataverse/ha...

It’s the largest comparative study of party youth wing members ever conducted, with survey responses from over 5,000 members of 12 centre-left and centre-right youth wings in 6 countries. 🧵

Today at 4pm GMT: Elisa Wirsching (@lsegovernment.bsky.social) is presenting "The Political Consequences of Police Slowdowns" at our Political Behaviour Seminar, organised together with @sarahobolt.bsky.social, @florianfoos.bsky.social &
@mathiaspoertner.bsky.social. Join us in London or on Zoom!

The latest episode, hosted by Sarina Sharma-Welsh in conversation with @miguelpereira.bsky.social, is about how politicians learn what voters want, why elite blind spots persist, and how representation can get distorted.

Listen here: pod.link/1851725697/e...