Nathan Blascak

Has anyone yet run a head-to-head comparison of the different advice that competing AI tools offer for expecting parents and for parents of newborns, infants, and toddlers?

tldr: nature of previous fraud exposure matters for take-up of new precautionary actions. More serious past experience ➡️ higher take-up. This updated version has new results examining what happens to consumer credit outcomes after freezing their credit report.

Updated working paper with my KC Fed Colleague Ying Lei Toh examine how past experiences with fraud affect take-up of new precautionary actions (e.g., credit report freezes) in consumer credit markets: www.philadelphiafed.org/-/media/FRBP...

What Newly Released Medicaid Data Do and Don’t Tell Us | KFF On February 14, 2026, CMS released a dataset with provider-level spending data that the agency suggests could be used to identify unusual billing patterns for specific services, states, or providers. ...

I’m always for more data. But, be careful using the new Medicaid spending data released by the Trump administration. It’s missing a lot of important details and context.
www.kff.org/medicaid/wha...

The extremely loosely goosey nature of data governance in AI land means that use of some types of confidential data may end up being signals of true human effort. The AI assisted papers that have been demonstrated only work because data is on the open internet and already cleaned/aggregated

I'm teaching a new course at Stern on AI in Finance and opening it up!

Syllabus/slides on Github: github.com/arpitrage/ai...

Weekly summaries on Substack
arpitrage.substack.com/p/1-three-ru...

First post is on Amdahl's Law, Jevons' Paradox, and why finance was slow to learn the bitter lesson

Then again, the twins sometimes just want to eat bread and butter and nothing else 🤷‍♂️

We also do instant mashed potatoes where I boil water in the electric kettle.

Got it! If I have time the night before, I prep something for the slow cooker for the next day (e.g , pasta sauce, pork shoulder, pot roast). Rice in a proper rice cooker is also super helpful since you can leave the rice in there for most of the day without it going bad.

For the entire family? Or just for the kids?

We study how radiologists use AI to diagnose pulmonary embolism (PE), tracking over 100,000 scans interpreted by nearly 400 radiologists during the staggered rollout of an FDA-approved diagnostic platform. When AI flags PE, radiologists agree 84% of the time; when AI predicts no PE, they agree 97%. Disagreement evolves substantially: radiologists initially reject AI-positive PEs in 30% of cases, dropping to 12% by year two. Despite a 16% increase in scan volume, diagnostic speed remains stable while per-radiologist monthly volumes nearly double, with no change in patient mortality—suggesting AI improves workflow without compromising outcomes. We document significant heterogeneity in AI collaboration: some radiologists reject AI-flagged PEs half the time while others accept nearly always; female radiologists are 6 percentage points less likely to override AI than male radiologists. Moderate AI engagement is associated with the highest agreement, whereas both low and high engagement show more disagreement. Follow-up imaging reveals that when radiologists override AI to diagnose PE, 54% of subsequent scans show both agreeing on no PE within 30 days.

Posted a very early stage draft with rock star collaborators.

Key question: when we actually roll out AI tools, how do people use them? Do they just defer completely? Does it improve productivity and ability?

We look in the medical setting of pulmonary embolisms
paulgp.com/papers/Radio...

Submission deadline for the Philadelphia Fed's Mortgage Market Research Conference is January 20th. Details here: bit.ly/4mT9Ocz

There’s a paradox around remote work. Jamie Dimon says it will kill productivity, while startups are hiring for remote roles. Who is right?

With Abhinav Gupta and Elena Simintzi we try to resolve this dispute

Paper: papers.ssrn.com/sol3/papers....
Substack: arpitrage.substack.com/p/remote-wor...

More on dementia & finances: similar to credit outcomes, we see declines on asset side start about 6 years before dementia onset, patterns are consistent with mistakes driving declines, not healthcare spending or spenddown

Can Machine Learning Target Health Care Fraud? Evidence From Medicare Hospitalizations The United States spends more than $4 trillion per year on health care, largely conducted by private providers and reimbursed by insurers. A major concern in this system is overbilling and fraud by h...

Recently published at JPAM: "Can Machine Learning Target Health Care Fraud? Evidence From Medicare Hospitalizations" by Shubhranshu Shekhar, Jetson Leder-Luis, & Leman Akoglu.
doi.org/10.1002/pam....

Best video games I played in 2025:

1. Finally played Outer Wilds. 10/10 no notes, go play it without spoiling yourself. It’s like a fun Myst with sweet space physics

Borderlands 4

www.metacritic.com/game/borderl...

Gone are the days where I can chase ultra-rare loot, but I've found BL4 to be a lot fun when I've found time to play. New open world design works for me (though could be improved) and I'm enjoying the story so far.

Elder Scrolls IV: Oblivion Remastered

www.metacritic.com/game/the-eld...

Nostalgia definitely got me here, but the remaster looks fantastic and the game plays almost exactly how I remembered it when it was originally released. Might still be my favorite open-world game.

Clair Obscur: Expedition 33

www.metacritic.com/game/clair-o...

I don't have much time to devote to RPGs anymore, but it was hard to ignore the hype. Totally deserves it's accolades - combat is fun, characters are memorable, and the music is superb.

Indiana Jones and the Great Circle

www.metacritic.com/game/indiana...

Started it in 2024, finished in 2025. I mentioned in my post last year just how faithful the game is to the original movies. True to the very end. Extra points for being able to sink either <20 or >40 hours into it

Continuing an annual tradition (following @paulgp.com ). A (very) short list of great games I found time to play this year:

Been doing this for the past year and a half with my wife. 💯 agree RE: the health benefits!

New paper with @instrumenthull.bsky.social and Michal Kolesár on leniency/judge IV designs.

This article is targeted for the Journal of Economic Perspectives, and so we wrote it with the goal of being accessible to a wide range of users, including advanced undergrads!🧵

arxiv.org/abs/2511.03572

An R&R and an acceptance on the same day...universe has a strange way of compensating for a full weekend of potty training the twins...

Missouri’s Medicaid Contraction and Consumer Financial Outcomes | American Journal of Health Economics: Vol 11, No 4 Abstract In July 2005, the state of Missouri implemented a series of cuts to its Medicaid program. These cuts resulted in the elimination of the Medical Assistance for Workers with Disabilities progra...

My paper on the consumer financial impacts of Missouri's 2005 Medicaid cut with @1armedeconomist.bsky.social and Slava Mikhed is finally out in the fall issue of AJHE: www.journals.uchicago.edu/doi/10.1086/...

🚨 JOB MARKET PAPER ALERT! 🚨

Why do firms provide different workplace amenities? And how does amenity provision affect labor market inequality? 🧵

Understanding Preferences for Payment Cards using Household Scanner Data The Federal Reserve Board of Governors in Washington DC.

ICYMI: New #FEDSPaper: Understanding Preferences for Payment Cards using Household Scanner Data: www.federalreserve.gov/econres/feds... #EconSky

🚨New predoc positions!🚨

Join @alexbartik.bsky.social and me to work on developing LLM tools to analyze zoning regulations and their impacts on housing affordability.

One position starting at the "normal" cycle next year, and another ASAP.

Apply here: apply.interfolio.com/176538

The fall edition of the @ashecon.bsky.social newsletter came out last week with 6 great articles

1. @jimflynn9.bsky.social interviewed ASHEcon President-Elect @johncawley.bsky.social

www.ashecon.org/activities/n...

1/7

Posted a short blog post with updated data (and public repo with data) of current state of Econ job market:

paulgp.com/2025/10/08/j...