I didn't understand an econ paper unless I'd gone to the trouble of taking it to pieces and putting it back together, better still programmed the thing in a computer and solved it myself.

One of the things I discovered about my own learning was that unless I went to the trouble of trying to reconstruct whatever model, argument, proof, reasoning myself, step by step, from scratch, I did not really see or understand its whole in my mind.

Immigration raids during Trump II have increased daily student absences by 22 percent in the California Central Valley, with largest increases among the youngest students.

Getting nervous for the talk I'm about to give at a workshop about "using AI to drive impact" which features slides such as these.

'You’re probably thinking, screw you, my doctor would tell me if something was really wrong, or else they wouldn’t have sent these. But do you know that for sure? Because there sure are a lot of numbers here and a lot of arrows up and down."

SNAP surveys SNAP users. Already half of them are saying they are skipping meals.

“Socialism-any of various egalitarian economic and political theories or movements advocating collective or governmental ownership and administration of the means of production and distribution of goods” Merriam-Webster www.merriam-webster.com/dictionary/s...

A List of Things Said to Have Been Ruined by Women 🧵

Any pro-democracy, pro-market lessons for the world as formerly robust democracies slip rapidly towards autocracy?

Earlier this week I came across a book with this dedication page (from 1938).

Part of the story of the Trump administration is the effort to demolish state capacities. Some will be very hard to rebuild and that is the point (thread)

(Reuters) - Meta internally projected late last year that it would earn about 10% of its overall annual revenue – or $16 billion – from running advertising for scams and banned goods, internal company documents show. $META @reuters.com www.reuters.com/investigatio...

New incredible detail here: ICE says a match in its facial recognition app Mobile Fortify is a "definitive" determination of a person's status, and that this overrides birth certificates. This is an app ICE is using in the field to scan people www.404media.co/ice-and-cbp-...

We have reached the point where the *American Bar Association* cannot find attorneys willing to represent them in litigation against the Trump administration. www.washingtonpost.com/national-sec...

This is a fantastic, well-supported 3-year post-doc in our Division of Medical Ethics at Penn. Please share (and apply if interested!)

Total federal spending is up +7% in 2025 over 2024 year-to-date to Oct 20. The story that the fed govt is tightening its belt is contradicted by its own real-time expenditure data. Admin spectacularly hammering some things but raising spending elsewhere. Was -7% just after Inauguration Day.

LLMs can be useful for some things, but simulating human research participant responses isn’t one of them

Wow. Harvard nuking its PhD programs - Science PhD admissions reduced by more than 75% - Arts & Humanities reduced by about 60% - Social Sciences by 50–70% - History by 60% - Biology by 75% - The German department will lose all PhD seats - Sociology from six PhD students to zero

The obvious incentives being created here is that on aggregate, most faculty will avoid Texas if they have a choice, or administrative positions if they can. For a while, this discouraged red state leaders from draconian attacks on faculty. But no more. They value subservience over excellence.

Dr. Amy Finkelstein from MIT will join us virtually on October 29 at noon ET to discuss “Facts and Fallacies: Rethinking US Healthcare.” Thanks to @bcfginitiative.bsky.social for co-hosting this event with us. Register here! chibe.upenn.edu/event/amy-fi...

The energy at the #NIH rally today was amazing and contagious. Huge turnout, huge pro-science energy. 1/ 🧪#NoKings

NHANES runs mobile clinics that travel the country measuring height, weight, & blood pressure while collecting blood and urine samples. These samples are our only national source for tracking everything from blood sugar to hormones, heavy metals, and more. The entire operation has been eliminated.

Wow. NHANES js incredibly for population health surveillance, and is nationally representative as well. What a loss.

I am delighted to share that Nobel laureates Esther Duflo and Abhijit Banerjee will join our Department of Economics @econ.uzh.ch at the University of Zurich on July 1, 2026, as Lemann Foundation Professors of Economics. 🧵 1/7

Today my @nytimes.com colleagues and I are launching a new series called Lost Science. We interview US scientists who can no longer discover something new about our world, thanks to this year‘s cuts. Here is my first interview with a scientist who studied bees and fires. Gift link: nyti.ms/3IWXbiE

(1) banger (2) i wish non-economists would realise just how much time each economics paper takes to write (because of our norms about how thorough each paper has to be)

“My biggest fear is going to the hospital." Pregnant immigrants are terrified ICE will show up outside the doctors' office or at the hospital. So they're skipping the care necessary to ensure a healthy birth. Some experience dangerous complications as a result. 19thnews.org/2025/10/preg...

Nice chart from @ourworldindata.org showing the contrast between what Americans die of (heart disease and cancer) v what the US media reports on (homicide and terrorism). This naturally leads to it being trickier to build a fact based world view ourworldindata.org/does-the-new...

Reports raise red flags: Georgia spent $54M on admin costs for its #Medicaid waiver, nearly twice the $26M spent on care, while enrolling under 3,500 people. CMS still extended the costly program that ties coverage to work requirements. www.cbpp.org/research/fed...

This is a breathtaking abuse of the law and power by the President of the United States. America is on the brink of martial law. Do not be silent.

Harmeet Dhillon (DOJ) publicly targeted this judge on Twitter a couple weeks ago.

“Littered with errors including three nonexistent academic references and a made-up quote from a Federal Court judgement.” Deloitte issues refund to (Aus) government for using AI in $440k report

This, in a nutshell, is the dilemma for actual conservative faculty on campus. It is very hard to reconcile sincere commitment to free speech w right-wing demands to shutter that speech. (Left-wing demands too, but less cognitive dissonance there). www.nytimes.com/2025/09/29/u...

The Trump Administration is defunding important surveys and undermining federal statistical agencies, suppressing data that would reveal the harmful effects of the Republican megabill’s deep cuts and leaving families’ struggles harder to track. www.cbpp.org/research/pov...

Serious scholars have examined what happens when we change the number of H1-B visas issued. Cities that get more H1-B immigrants subsequently see the wages of natives *rise* substantially. Skilled immigrants bring new ideas, fill labor shortages and make us all more productive.

lots of people saying that ACIP voted against the MMRV vaccine which is not really what happened 1) they voted to not recommend MMRV and instead to get MMR and V separately 2) they voted to keep the MMRV under coverage for the Vaccines for Children program 3) they seem confused by their own votes

The world’s first successful treatment of a patient with a personalized CRISPR gene editing therapy was carried out by a team at Penn Medicine and CHOP. This history-making breakthrough involved a child diagnosed with a rare genetic disorder. Read More: https://bit.ly/3Fd0Kzp

Children will die because of RFK Jr. Others may lose hearing or vision. Many more will suffer a horrible bout of illness for a week or more for no good reason. thehill.com/policy/healt...

This graph shows a U.S. public health triumph: near-elimination of pediatric hepatitis B through universal birth vaccination. After 30 years of extraordinary progress, ACIP tomorrow considers dismantling it. Medical justification: none. Consequences: catastrophic. www.cdc.gov/acip/downloa...

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We're witnessing the most aggressive, fanatical crackdown on free speech in my lifetime. The speed and breadth of government censorship and private sector and nonprofit capitulation has been astonishing. As has the lack of urgency/silence from people who've long claimed to care about this stuff.

Posobiec - whose ties to white supremacists are legion - wrote a book last year called “Unhumans” in which he labeled half the country UNHUMAN It is language designed to inspire political violence yet our cable news channels have made him a talking head about political violence

Reducing access to abortions ... - increases families' economic hardship, - increases families' debt, - increases income inequality, - increases housing insecurity, and - increases financially motivated crime rates.

“An extra six months, an extra year, a possible lifetime: That’s time that my talented 12-year-old son was denied. In his last months, Aryeh talked enthusiastically about starting middle school with his friends; about his upcoming bar mitzvah, which he began preparing for but didn’t celebrate…” 💔

When the world’s leading science journal is publishing how-to’s for top scientists to leave your formerly world-leading science enterprise, you’ve done something wrong. It’s not too late to reverse course, although the damage already done will reverberate for decades.

Some personal news: I've been fired from the Washington Post in the aftermath of the Charlie Kirk shooting. Thread incoming. substack.com/@karenattiah...

The First10EM Research Roundup for September 2025 It has been a while since I have critically appraised. Life without medical journals is sort of nice, but I guess it just isn’t me, so I am back and nerdier than ever. That means there are some strange selections this time around, but there are…

A couple of weeks later, and eight custom security rules later, my website traffic is successfully managed. Bots were overwhelming it, and the worst offenders were pretending not to be bots (fake referrers, fake user agents)—I'm gonna assume those are AI scrapers. Now they're throttled and blocked.

Hey, Cloudflare gave me full access to their suite of services via Project Galileo, their program to protect human rights, civil society, journalism, and democracy websites, so that means my highest-traffic website is now better protected. That was nice of them.