David Broockman

@dbroockman.bsky.social

Day job = Associate Prof. of Political Science at UC Berkeley. Tweets = personal views.

New short paper w @jkalla.bsky.social ! Candidates gain from moderation, but less than many theories expect. Many conclude voters must not care about issues. This is wrong. Small *average* effects mask large effects on specific issues & are consistent with widespread issue-based voting 🧵

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New paper in Science: In a platform-independent field experiment, we show that reranking content expressing antidemocratic attitudes and partisan animosity in social media feeds alters affective polarization. 🧵

Today, social media platforms hold the sole power to study the effects of feed-ranking algorithms. We developed a platform-independent method that reranks participants’ feeds in real time and used this method to conduct a preregistered 10-day field experiment with 1256 participants on X during the 2024 US presidential campaign. Our experiment used a large language model to rerank posts that expressed antidemocratic attitudes and partisan animosity (AAPA). Decreasing or increasing AAPA exposure shifted out-party partisan animosity by more than 2 points on a 100-point feeling thermometer, with no detectable differences across party lines, providing causal evidence that exposure to AAPA content alters affective polarization. This work establishes a method to study feed algorithms without requiring platform cooperation, enabling independent evaluation of ranking interventions in naturalistic settings.

Still thinking about this article. It’s always been a sore spot in YIMBY circles that so many progressive foundations pour money into NIMBYism, and I’m glad it’s finally being aired in public. Keep talking about it. www.insidephilanthropy.com/home/philant...

Philanthropy Needs to Pick a Side on the Housing Construction Debate

Despite California’s severe housing shortage, foundations are still funding on the wrong side of the housing fight there, guest author Ned Resnikoff writes.

insidephilanthropy.com

🚨NEW PAPER: Why are Members of Congress so extreme? We conducted a 4-wave panel of thousands of voters in 27 districts during last year’s primary AND general elections to trace polarization’s roots The results challenge conventional wisdom… and suggest lessons for parties🧵👇

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Apparently my work on ideology is coming up in TikToks to justify the idea that extreme positions gain votes. For the record, I don't think my work indicates this. Rather, it suggests that the most advantageous moderation is on the specific issues where a party is out of step with public opinion.

Interesting that I’m not seeing takes that this will help Trump politically because 1) moving to the extremes will turn out his base and/or 2) economic reality doesn’t matter, only elite messaging about the economy. Makes you think.

Matthew Yglesias @mattyglesias.bsky.social · last yr.

I think Trump’s increasingly extreme trade policies will probably help the GOP electorally by juicing base turnout — the only way they could make this go better for themselves would be by banning abortion and privatizing Medicare.

🚨 NEW PAPER: When low-income Americans get $1,000/month for 3 years, what happens to their political views & behavior? The OpenResearch Unconditional income Study reveals surprising findings about the effects of income on politics... 🧵

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With Fox News hosts nominated for the cabinet, I wanted to share takeaways from two recently-accepted papers w @jkalla.bsky.social on partisan TV. There's been much skepticism that partisan TV actually affects public opinion. Our findings rebut that skepticism: partisan media matters! 🧵

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