Sebastián Vallejo Vera
@svallejovera.bsky.social
150 followers 240 following 28 posts
Assistant Professor at Western University | Legislative politics, gender and politics, racism and politics, and NLP (and politics). http://svallejovera.com
Posts Media Videos Starter Packs
Pinned
svallejovera.bsky.social
Just *published* our paper with @westernupolisci.bsky.social PhD student, Hunter Driggers, on LLM bias from party cues in annotation tasks. We extend a previous study showing annotation bias from human coders in the presence of party cues… LLM show similar bias 🧵:

rdcu.be/eIKCj
LLMs as annotators: the effect of party cues on labelling decisions by large language models
Humanities and Social Sciences Communications - LLMs as annotators: the effect of party cues on labelling decisions by large language models
rdcu.be
Reposted by Sebastián Vallejo Vera
amandafriesen.bsky.social
In 2024, we surveyed US scholars about how, when, why they do (or don’t!) personally participate. We find a few patterns, some differences by subfield and variation in our attitudes toward the place of personal politics in our work, especially the impacts on our credibility with the public.
cambup-polsci.cambridge.org
#OpenAccess from @pspolisci.bsky.social -

The Political Engagement of Political Scientists: Partisans, Public Scholars, and Teachers/Pedagogues - https://cup.org/4pLx0Mn

- @pauldjupe.bsky.social, @amandafriesen.bsky.social & Jacob R. Neiheisel

#FirstView
Logo of PS: Political Science & Politics (PS) with #OpenAccess, next to a vibrant image of people participating in a Pride parade, holding a colorful rainbow flag.
Reposted by Sebastián Vallejo Vera
svallejovera.bsky.social
Just *published* our paper with @westernupolisci.bsky.social PhD student, Hunter Driggers, on LLM bias from party cues in annotation tasks. We extend a previous study showing annotation bias from human coders in the presence of party cues… LLM show similar bias 🧵:

rdcu.be/eIKCj
LLMs as annotators: the effect of party cues on labelling decisions by large language models
Humanities and Social Sciences Communications - LLMs as annotators: the effect of party cues on labelling decisions by large language models
rdcu.be
Reposted by Sebastián Vallejo Vera
svallejovera.bsky.social
This is not entirely surprising: you train a model with huge amounts of human-created biased data, it will probably replicate this behaviour. The main takeaway here is that LLMs are biased in a very LLM way. They cling to these cues and do not self-correct (like human coders).
svallejovera.bsky.social
So we find the same direction of the effect, but greater magnitude. In any case, keep this in mind when using LLM as annotators, and check the paper for some additional ‘best practices’ when using LLM. Topes!
svallejovera.bsky.social
This is not entirely surprising: you train a model with huge amounts of human-created biased data, it will probably replicate this behaviour. The main takeaway here is that LLMs are biased in a very LLM way. They cling to these cues and do not self-correct (like human coders).
svallejovera.bsky.social
We tested how LLM annotate text on immigration by only changing the party names on the text. LLM were more likely to label statements as negative when applying a right-leaning party cues, and positive when applying a left -leaning party cues.
svallejovera.bsky.social
Just *published* our paper with @westernupolisci.bsky.social PhD student, Hunter Driggers, on LLM bias from party cues in annotation tasks. We extend a previous study showing annotation bias from human coders in the presence of party cues… LLM show similar bias 🧵:

rdcu.be/eIKCj
LLMs as annotators: the effect of party cues on labelling decisions by large language models
Humanities and Social Sciences Communications - LLMs as annotators: the effect of party cues on labelling decisions by large language models
rdcu.be
Reposted by Sebastián Vallejo Vera
llschenoni.bsky.social
If we set aside ad-hoc explanations, two forces stand out in shaping global development: colonial institutions and war—even if the former fails to explain Europe itself. Latin America has long tilted the debate away from the latter, but what if the real driver was war here as well?👇
Beyond Colonialism: The Long Shadow of War in Latin America’s Development
Capable states that enforce the rule of law, secure property rights, and provide public goods are prerequisites for development, but where do they originate?
cambridgeblog.org
Reposted by Sebastián Vallejo Vera
Reposted by Sebastián Vallejo Vera
westernupolisci.bsky.social
The New York Times
What to know about the North American summit taking place without the U.S.
As leaders of Canada and Mexico met this week to discuss trade, Professor @svallejovera.bsky.social Vallejo Vera explains what the meeting aims to accomplish.

www.nytimes.com/2025/09/18/w...
Leaders of Canada and Mexico Talk Trade and Security Without U.S.
www.nytimes.com
Reposted by Sebastián Vallejo Vera
profdansmith.bsky.social
🎉Now online (open access): "Hidden Majoritarianism and Women’s Career Progression in Proportional Representation Systems" at @apsrjournal.bsky.social. @alicirone.bsky.social, @teele.bsky.social, Gary Cox, @fiva.no. www.cambridge.org/core/journal...
Reposted by Sebastián Vallejo Vera
mattpolacko.bsky.social
🚨New Publication🚨

Using the entire #Canadian Election Study (1965–2021), I examine voter turnout by class, education, & income over time & test whether the offerings of political parties impact these relationships.

Available #OpenAccess in @cjps-rcsp.bsky.social
#polisky

doi.org/10.1017/S000...
Reposted by Sebastián Vallejo Vera
ericpolisci.bsky.social
Stony Brook is hiring in political psychology (assistant professor). Please Share! Feel free to reach out if you have question. For more information: apply.interfolio.com/170193
Reposted by Sebastián Vallejo Vera
amandafriesen.bsky.social
We are very excited to have the brilliant @blairwelsh.bsky.social joining the Dept of Political Science @westernu.ca! Look for big things and important work in empirical IR; great for us and great for Canada!

politicalscience.uwo.ca/about_us/new...
News
Current news and announcements from the Department of Political Science at Western University.
politicalscience.uwo.ca
Reposted by Sebastián Vallejo Vera
amandafriesen.bsky.social
Come work with me/us!!! Happy to answer questions about our dept, Western, and Canadian academia. I absolutely love it here and highly recommend. Several of us will be at APSA and happy to meet. 🇨🇦
matthewlebo.bsky.social
Political Science at Western University, Canada is searching for three tenure track assistant professors. There are two ads, one in International Politics (IR or comparative) and one in Comparative or Canadian. Ads are here: www.uwo.ca/facultyrelat...
Faculty (UWOFA)
Western University, in vibrant London, Ontario, delivers an academic and student experience second to none.
www.uwo.ca
svallejovera.bsky.social
Come work with us at Western U!! Located at one of the Top 5 Londons in the world.
matthewlebo.bsky.social
Political Science at Western University, Canada is searching for three tenure track assistant professors. There are two ads, one in International Politics (IR or comparative) and one in Comparative or Canadian. Ads are here: www.uwo.ca/facultyrelat...
Faculty (UWOFA)
Western University, in vibrant London, Ontario, delivers an academic and student experience second to none.
www.uwo.ca
Reposted by Sebastián Vallejo Vera
matthewlebo.bsky.social
Political Science at Western University, Canada is searching for three tenure track assistant professors. There are two ads, one in International Politics (IR or comparative) and one in Comparative or Canadian. Ads are here: www.uwo.ca/facultyrelat...
Faculty (UWOFA)
Western University, in vibrant London, Ontario, delivers an academic and student experience second to none.
www.uwo.ca
Reposted by Sebastián Vallejo Vera
tiagoventura.bsky.social
🚨 Paper now as "just accepted" at @The_JOP. We ran the first WhatsApp deactivation experiment focused on multimedia content ahead of the 2022 election in Brazil. We find a reduction in users' recall of false rumors -- and, to a smaller degree, of true news. Null effects on attitudes. Full thread ⬇️
csmapnyu.org
In the Global South, WhatsApp is more popular than X or Facebook.

New in @The_JOP, we ran a WhatsApp deactivation experiment during Brazil’s 2022 election to explore how the app facilitates the spread of misinformation and affects voters’ attitudes.

www.journals.uchicago.edu/doi/abs/10.1...
Abstract: In most advanced democracies, concerns about the spread of misinformation are typically associated with feed-based social media platforms like Twitter and Facebook. These platforms also account for the vast majority of research on the topic. However, in most of the world, particularly in Global South countries, misinformation often reaches citizens through social media messaging apps, particularly WhatsApp. To fill the resulting gap in the literature, we conducted a multimedia deactivation experiment to test the impact of reducing exposure to potential sources of misinformation on WhatsApp during the weeks leading up to the 2022 Presidential election in Brazil. We find that this intervention significantly reduced participants’ recall of false rumors circulating widely during the election. However, consistent with theories of mass media minimal effects, a short-term change in the information environment did not lead to significant changes in belief accuracy, political polarization, or well-being.
svallejovera.bsky.social
The running joke in our family is just asking back “ok, but where are you REALLY from?”.
olufemiotaiwo.bsky.social
just saying: if you didn't grow up crafting a default answer to "what are you/where are you from?" with some version of "what do you mean?" you may want to consult people who did about what's going on here
Reposted by Sebastián Vallejo Vera
jacklucas.bsky.social
"Place Types." Excited that this paper with @sborwein.bsky.social is now available. We develop a new typology of place types in Canada at a fairly fine-grained level of geography, and then show how these place types relate to Canadian politics. doi.org/10.1017/S000...
Reposted by Sebastián Vallejo Vera
jacklucas.bsky.social
Happy to report that this article is now available: doi.org/10.1017/S000.... See Tyler's thread below for more detail on the associated R package and interactive online app.