Johan Ugander
@jugander.bsky.social
3.2K followers 480 following 130 posts
Associate Professor, Yale Statistics & Data Science. Social networks, social and behavioral data, causal inference, mountains. https://jugander.github.io/
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jugander.bsky.social
📣 Yale workshop, Oct 16-17! 📣 How could/should content ranking work? What's new in content moderation? How can platforms promote civility? Hosted by Yale's Institute for Foundations of Data Science (FDS). Great speakers! Submit posters by 9/22! Spread the word! yalefds.swoogo.com/socialalgori...
New Directions in Social Algorithms Research on October 16-17, 2025 at Yale University
As social media algorithms increasingly mediate social experiences, there has been a rapid increase in research on the effects of how these algorithms are configured, alternatives to engagement-centri...
yalefds.swoogo.com
Reposted by Johan Ugander
mathewkiang.com
Have you ever wondered how to ensure a loss in Candyland though?

github.com/mkiang/candy...
github.com
Reposted by Johan Ugander
yaledatascience.bsky.social
Join the Social Algorithms Workshop at Yale to learn how algorithms amplify ideas, and (sometimes) mislead us, organized by @jugander.bsky.social w/ talks by @brendannyhan.bsky.social & @informor.bsky.social. Use code sawitonX on last registration page for 25% off yalefds.swoogo.com/socialalgori...
jugander.bsky.social
Re-upping for 2025.
apoorvalal.com
The Manski bound for the number of Nobel Prizes received by Chuck Manski by next Monday is [0, 1]
Reposted by Johan Ugander
economeager.bsky.social
"Many people still have an elderly relative who survived a bout of severe childhood illness; not one of us has an elderly relative who did not."

This is the best and perhaps most important illustration of sample selection i have seen in a good long while.
trevondlogan.bsky.social
Good history helps us avoid nostalgia. The great article “Economic History and the Historians” (2020) by Anne McCants reminds me why nostalgia can get us in trouble. Two of her examples are very relevant to today: vaccinations and the popular narrative of some economic “good old days.”
Getting vaccinated is unpleasant. Dying of measles is worse. In the decade before the 1963 vaccine for measles emerged, an average of 475 Americans died from measles every year, most of them children. This (absolute) number had dropped to a low of 1 in 1981, despite a steadily increasing population that might have hypothetically contributed additional cases. Sadly, the number of measles cases in the United States has been steadily climbing upward again because we seem not to remember the ravages of the disease so much as the inconvenience of the shot—even without taking into account the absurd rejection of the solid scientific evidence in favor of vaccinations. Many people still have an elderly relative who survived a bout of severe childhood illness; not one of us has an elderly relative who did not. The blurring of the historical evidence for and against vaccination that arises from strangely incongruous historical narratives allows a seemingly inconsequential but nonetheless deadly nostalgia to run rampant. Another example of dangerous reverence for the past concerns the flurry of popular enthusiasm lately (at least if the pundits of the 2016 American election are to be believed) for the “good old days” of the 1950s when a family could live securely on just one income (in these nostalgic accounts, that one income is usually a man’s). Lest we forget, these are the same good old days of poor air quality and measles. Maybe trivial in comparison but certainly indicative of the scope of the cognitive problem that nostalgia presents, the average size of a new home built in America in 1950 was 983 sq. ft.; by 2010, the average size had risen to 2,392 sq. ft. Given that families were larger on average in the 1950s than they were in 2010, per capita space allocation had risen even faster than total area. Although we might not need that much personal space, many of us have become used to it. Older furniture now looks tiny compared to what is now on offer in showrooms, whereas older television sets were behemoths with miniscule screens showing programs in glorious black and white.
Reposted by Johan Ugander
pessimistsarc.bsky.social
Happy Birthday Google

For many of your 27 years you were called a lazy vice. Finally you have attained the status of a thoughtful virtue of the good old days.

🥂 🥳
jugander.bsky.social
Very excited for this talk Mor!!! Should lead to a lively discussion. The purpose of the workshop is to ask/ponder/problematize the big questions!
jugander.bsky.social
I'm really looking forward to this workshop Oct 16-17! Poster submission deadline today 🗓️ 9/22, travel funding available for students and postdocs! Join us!
jugander.bsky.social
📣 Yale workshop, Oct 16-17! 📣 How could/should content ranking work? What's new in content moderation? How can platforms promote civility? Hosted by Yale's Institute for Foundations of Data Science (FDS). Great speakers! Submit posters by 9/22! Spread the word! yalefds.swoogo.com/socialalgori...
New Directions in Social Algorithms Research on October 16-17, 2025 at Yale University
As social media algorithms increasingly mediate social experiences, there has been a rapid increase in research on the effects of how these algorithms are configured, alternatives to engagement-centri...
yalefds.swoogo.com
Reposted by Johan Ugander
matthholden.bsky.social
Happy 4^ / 3^2 / 5^2 day!!! (3^2/ 4^2 / 5^2 for us weird Americans) Not too many days satisfy the Pythagorean thm. @amermathsoc.bsky.social @austms.bsky.social @stevenstrogatz.com @monsoon0.bsky.social ht Peter Baxter for noticing. Looking forward to coming back to the US for joint maths in Jan.
jugander.bsky.social
A (different) version of this that I've heard is that it's hard (for runners, e.g.) to train power (build muscle) at altitude because at altitude (say, >9k) you're usually rate-limited by your aerobic fitness, not your muscles. So some who live high go low semi-regularly to train power.
Reposted by Johan Ugander
eegilbert.org
The School of Information at Michigan is looking for its next John Derby Evans Professor in Information. It's open at the Assistant and Associate levels, and its a broad search: anyone working at the intersection of tech and society can apply. Please share!

www.si.umich.edu/people/facul...
John Derby Evans Professorship in Information (Assistant or Associate Professor) | umsi
The University of Michigan School of Information (UMSI) invites applications for a tenure-track faculty position focusing on technology and society.
www.si.umich.edu
jugander.bsky.social
There is travel assistance (and free registration) available for PhD students and postdocs presenting posters. Please reach out if cost is a concern! yalefds.swoogo.com/socialalgori...
Social Algorithms Workshop: Poster Session
yalefds.swoogo.com
jugander.bsky.social
📣 Yale workshop, Oct 16-17! 📣 How could/should content ranking work? What's new in content moderation? How can platforms promote civility? Hosted by Yale's Institute for Foundations of Data Science (FDS). Great speakers! Submit posters by 9/22! Spread the word! yalefds.swoogo.com/socialalgori...
New Directions in Social Algorithms Research on October 16-17, 2025 at Yale University
As social media algorithms increasingly mediate social experiences, there has been a rapid increase in research on the effects of how these algorithms are configured, alternatives to engagement-centri...
yalefds.swoogo.com
jugander.bsky.social
An outstanding new @3blue1brown.com guest video by Paul Dancstep on Sol Lewitt's incomplete open cubes. www.youtube.com/watch?v=_BrF...
For more on the "mistake" discussed at the end, see Rozhkovskaya & Reb (2015) "Is the List of Incomplete Open Cubes Complete?": link.springer.com/article/10.1...
Exploration & Epiphany | Guest video by Paul Dancstep
YouTube video by 3Blue1Brown
www.youtube.com
jugander.bsky.social
My award for most honest paper goes to: arxiv.org/abs/1804.02767 An arxiv-only paper describing v3 of YOLO, a vision algo that already had two published papers. With huge adoption already, authors were out of sell mode and just documented it as best they could. Sec 4 takes honesty to 11. 37k cites.
jugander.bsky.social
Google autocomplete's behavior here reminds me of @msalganik.bsky.social's very nice discussion of "algorithmic confounding" in Bit by Bit (2.4.2): www.bitbybitbook.com/en/1st-ed/ob... and @davidlazer.bsky.social et al.'s "Parable of google flu trends" (2014) paper: www.science.org/doi/10.1126/...
jugander.bsky.social
Google autocomplete is asking the important questions.
Reposted by Johan Ugander
quantamagazine.bsky.social
What’s the worst centrally symmetric convex shape for packing the plane? A hexagonal grid of circles covers 90.69% of the plane when optimally packed. An octagon with rounded corners covers a smidgen less: 90.24%. But is this shape the worst one?
www.quantamagazine.org/why-is-this-...
Reposted by Johan Ugander
tomerullman.bsky.social
thinking of calling this "The Illusion Illusion"

(more examples below)
jugander.bsky.social
Great interview with @stevenstrogatz.com with a lot of discussion of research advising. Parts reminded me of @eegilbert.org and @informor.bsky.social's (excellent) guides to PhD mentorship, with a big focus on ideation.
Eric's: docs.google.com/document/d/1...
Mor's: s.tech.cornell.edu/phd-syllabus/
Reposted by Johan Ugander
mathyawp.bsky.social
Come work with my fantastic colleagues! We have a job opening for someone in any area of operations research with a broad teaching porfolio.
See the ad:
math.hmc.edu/tenure-track...
Tenure Track (Operations Research) – Harvey Mudd College Mathematics
math.hmc.edu
Reposted by Johan Ugander
brendannyhan.bsky.social
New job ad: Assistant Professor of Quantitative Social Science, Dartmouth College apply.interfolio.com/172357

Please share with your networks. I am the search chair and happy to answer questions!
Reposted by Johan Ugander
nkgarg.bsky.social
New piece, out in the Sigecom Exchanges! It's my first solo-author piece, and the closest thing I've written to being my "manifesto." #econsky #ecsky
arxiv.org/abs/2507.03600
Screenshot of paper abstract, with text: "A core ethos of the Economics and Computation (EconCS) community is that people have complex private preferences and information of which the central planner is unaware, but which an appropriately designed mechanism can uncover to improve collective decisionmaking. This ethos underlies the community’s largest deployed success stories, from stable matching systems to participatory budgeting. I ask: is this choice and information aggregation “worth it”? In particular, I discuss how such systems induce heterogeneous participation: those already relatively advantaged are, empirically, more able to pay time costs and navigate administrative burdens imposed by the mechanisms. I draw on three case studies, including my own work – complex democratic mechanisms, resident crowdsourcing, and school matching. I end with lessons for practice and research, challenging the community to help reduce participation heterogeneity and design and deploy mechanisms that meet a “best of both worlds” north star: use preferences and information from those who choose to participate, but provide a “sufficient” quality of service to those who do not."