Johan Ugander
@jugander.bsky.social
Associate Professor, Yale Statistics & Data Science. Social networks, social and behavioral data, causal inference, mountains. https://jugander.github.io/
Pinned
Johan Ugander
@jugander.bsky.social
· Jul 1
📣 Update: I've moved to Yale, joining the Department of Statistics & Data Science as an Associate Professor today (July 1)! The last year's sabbatical here has been great for me and my family, and I am excited for great things ahead! Come visit! Trading the wind of freedom for light and truth!
"Understanding the strengths and limitations of community-based responses to misinformation" — very nice commentary by @ekvraga.bsky.social in PNAS, covering my recent paper on causal effects of Community Notes w/ @isaacslaughter.bsky.social @axelp.bsky.social @msaveski.bsky.social
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
www.pnas.org
November 26, 2025 at 7:35 PM
"Understanding the strengths and limitations of community-based responses to misinformation" — very nice commentary by @ekvraga.bsky.social in PNAS, covering my recent paper on causal effects of Community Notes w/ @isaacslaughter.bsky.social @axelp.bsky.social @msaveski.bsky.social
Reposted by Johan Ugander
I wrote about the fake account blowup on X this weekend. A genuine post-truth nightmare and proof that these companies have polluted their platforms so thoroughly and traded reality for profit that they've undermined the very idea of what the internet is supposed to be.
That MAGA Account Might Be a Troll From Pakistan
How X blew up its own platform with a new location feature
www.theatlantic.com
November 24, 2025 at 4:33 PM
I wrote about the fake account blowup on X this weekend. A genuine post-truth nightmare and proof that these companies have polluted their platforms so thoroughly and traded reality for profit that they've undermined the very idea of what the internet is supposed to be.
Powerful read. If you're a US resident age 18-35, consider registering for the National Marrow Donor Program (NMDP, formerly BeTheMatch): www.nmdp.org
A Battle with My Blood
When I was diagnosed with leukemia, my first thought was that this couldn’t be happening to me, to my family.
www.newyorker.com
November 23, 2025 at 4:15 AM
Powerful read. If you're a US resident age 18-35, consider registering for the National Marrow Donor Program (NMDP, formerly BeTheMatch): www.nmdp.org
Reposted by Johan Ugander
Yale’s Institute for Foundations of Data Science (FDS) @yaledatascience.bsky.social is seeking applications for postdoctoral positions. These are cool, generously supported, competitive positions, expected to last 2-3 years, for independent scholars working on the foundations of data science.
Yale University, Institute for the Foundations of Data Science
Job #AJO31114, Postdoc in Foundations of Data Science, Institute for the Foundations of Data Science, Yale University, New Haven, Connecticut, US
academicjobsonline.org
November 17, 2025 at 8:08 PM
Yale’s Institute for Foundations of Data Science (FDS) @yaledatascience.bsky.social is seeking applications for postdoctoral positions. These are cool, generously supported, competitive positions, expected to last 2-3 years, for independent scholars working on the foundations of data science.
📣 Postdocs at Yale FDS! 📣 Tremendous freedom to work on data science problems with faculty across campus, multi-year, great salary. Deadline 12/15. Spread the word! Application: academicjobsonline.org/ajo/jobs/31114 More about Yale FDS: fds.yale.edu
Yale University, Institute for the Foundations of Data Science
Job #AJO31114, Postdoc in Foundations of Data Science, Institute for the Foundations of Data Science, Yale University, New Haven, Connecticut, US
academicjobsonline.org
November 18, 2025 at 3:54 AM
📣 Postdocs at Yale FDS! 📣 Tremendous freedom to work on data science problems with faculty across campus, multi-year, great salary. Deadline 12/15. Spread the word! Application: academicjobsonline.org/ajo/jobs/31114 More about Yale FDS: fds.yale.edu
Reposted by Johan Ugander
In economics we call these Manski Bounds.
AI could end scarcity, end humanity - or boost trend growth by 0.2 percentage points
November 7, 2025 at 8:26 PM
In economics we call these Manski Bounds.
New office trinket: I 3D-printed "Lewitt's missing cube". Quite happy with how it turned out. Many thanks to Paul for sending me the stl file! Skip to 49:55 in his video to appreciate why this is fun.
November 4, 2025 at 9:21 PM
New office trinket: I 3D-printed "Lewitt's missing cube". Quite happy with how it turned out. Many thanks to Paul for sending me the stl file! Skip to 49:55 in his video to appreciate why this is fun.
Excellent report on experiences of @guidoimbens.bsky.social & Mary Wootters co-teaching "Causality, Decision Making, and Data Science" to undergrads at Stanford fall 2024: hdsr.mitpress.mit.edu/pub/uynpjlow... Course material here: stanford-causal-inference-class.github.io
November 3, 2025 at 4:14 PM
Excellent report on experiences of @guidoimbens.bsky.social & Mary Wootters co-teaching "Causality, Decision Making, and Data Science" to undergrads at Stanford fall 2024: hdsr.mitpress.mit.edu/pub/uynpjlow... Course material here: stanford-causal-inference-class.github.io
Reposted by Johan Ugander
ICYMI: Drop everything and spend 13 minutes with Amy Sherald--with her singular vision and talent, with her clarity about her central place in the jagged American story. You will be stirred by it all. www.cbsnews.com/video/amy-sh...
Artist Amy Sherald: The 60 Minutes Interview
Amy Sherald spent years painting in obscurity, and almost died from a rare heart condition. Now 52, the artist behind Michelle Obama's official portrait is one of America's most celebrated painters.
www.cbsnews.com
October 26, 2025 at 6:39 PM
ICYMI: Drop everything and spend 13 minutes with Amy Sherald--with her singular vision and talent, with her clarity about her central place in the jagged American story. You will be stirred by it all. www.cbsnews.com/video/amy-sh...
Connecticut is approach peak fall. Shots from Lake Wintergreen this morning. A glorious start to the day.
October 24, 2025 at 3:21 PM
Connecticut is approach peak fall. Shots from Lake Wintergreen this morning. A glorious start to the day.
Reposted by Johan Ugander
New paper alert!!! 🚨
“A Short History of Misinformation-at-scale and Efforts to Mitigate it” in the Journal of Public Policy and Marketing
drive.google.com/file/d/1Klg9...
This article traces the social construction of misinformation-at-scale through changes to content moderation.
“A Short History of Misinformation-at-scale and Efforts to Mitigate it” in the Journal of Public Policy and Marketing
drive.google.com/file/d/1Klg9...
This article traces the social construction of misinformation-at-scale through changes to content moderation.
donovan-2025-express-a-short-history-of-misinformation-at-scale-and-efforts-to-mitigate-it.pdf
drive.google.com
October 16, 2025 at 9:04 AM
New paper alert!!! 🚨
“A Short History of Misinformation-at-scale and Efforts to Mitigate it” in the Journal of Public Policy and Marketing
drive.google.com/file/d/1Klg9...
This article traces the social construction of misinformation-at-scale through changes to content moderation.
“A Short History of Misinformation-at-scale and Efforts to Mitigate it” in the Journal of Public Policy and Marketing
drive.google.com/file/d/1Klg9...
This article traces the social construction of misinformation-at-scale through changes to content moderation.
Reposted by Johan Ugander
Reposted by Johan Ugander
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...
October 6, 2025 at 3:21 PM
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...
Re-upping for 2025.
The Manski bound for the number of Nobel Prizes received by Chuck Manski by next Monday is [0, 1]
October 6, 2025 at 2:45 PM
Re-upping for 2025.
Reposted by Johan Ugander
"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.
This is the best and perhaps most important illustration of sample selection i have seen in a good long while.
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.”
October 1, 2025 at 10:45 AM
"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.
This is the best and perhaps most important illustration of sample selection i have seen in a good long while.
Reposted by Johan Ugander
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.
🥂 🥳
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.
🥂 🥳
September 27, 2025 at 10:30 PM
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.
🥂 🥳
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.
🥂 🥳
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!
📣 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
September 22, 2025 at 8:09 AM
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!
Reposted by Johan Ugander
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.
September 16, 2025 at 8:48 AM
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.
Reposted by Johan Ugander
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...
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
September 15, 2025 at 5:27 PM
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...
www.si.umich.edu/people/facul...
📣 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
September 12, 2025 at 12:28 PM
📣 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...
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...
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
September 9, 2025 at 4:04 PM
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...
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...
Google autocomplete is asking the important questions.
September 3, 2025 at 12:09 PM
Google autocomplete is asking the important questions.
Reposted by Johan Ugander
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-...
www.quantamagazine.org/why-is-this-...
June 28, 2024 at 3:01 PM
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-...
www.quantamagazine.org/why-is-this-...
Reposted by Johan Ugander
thinking of calling this "The Illusion Illusion"
(more examples below)
(more examples below)
December 1, 2024 at 2:33 PM
thinking of calling this "The Illusion Illusion"
(more examples below)
(more examples below)