iiinova — where your digital self keeps evolving

⑆Luke Stein⑈ @lukestein.com · 27/03/2025

Today’s shitpost is tomorrow’s Beamer theme @spencerbarnes.bsky.social

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⑆Luke Stein⑈ @lukestein.com · 26/03/2025

“So, why don’t you start by telling us a bit about your job market paper”

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⑆Luke Stein⑈ @lukestein.com · 13/03/2025

Quick and dirty: Trading days from first entering “correction” territory (don't like that term, but 🤷) until hitting deepest drawdown: - 20% turn around the next day - 40% turn around two weeks – two months - 27% five months – one year - 13% more than a year

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⑆Luke Stein⑈ @lukestein.com · 13/03/2025

Lunchtime chat w colleague Linghang. In spirit of what our MSF students are learning to code, here’s max drawdown following every 10% S&P 500 correction back to 1980 (n=15 excl. today) - 6 hit a new high before dropping 15% - Another 6 fell >25% - Only 3 turned around at 15–25% (all close to 20%)

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⑆Luke Stein⑈ @lukestein.com · 03/03/2025

This is my Twitter DM inbox

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⑆Luke Stein⑈ @lukestein.com · 15/01/2025

GPT 4o does a decent job thinking through the pros and cons of interpreting this question as Fahrenheit vs Celsius vs Kelvin, btw

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⑆Luke Stein⑈ @lukestein.com · 10/01/2025

Regression discontinuity at 15%

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⑆Luke Stein⑈ @lukestein.com · 31/12/2024

Thanks Michael (and will look for Lisa) On mobile, it’s - Search for account - Click the “three dots” menu and “report account” - Check “misleading account” and finish the report

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⑆Luke Stein⑈ @lukestein.com · 30/12/2024

Bumper stickers that go hard

Bumper sticker stating “Transgender Vereran: I fought for your right to hate me”

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⑆Luke Stein⑈ @lukestein.com · 20/12/2024

You want me to listen, understand, care, or help?

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⑆Luke Stein⑈ @lukestein.com · 12/12/2024

It gives me true joy that the San Francisco Chronicle is breaking analemma news on their front page

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⑆Luke Stein⑈ @lukestein.com · 10/12/2024

“Price is only an issue in the absence of value” 😶

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⑆Luke Stein⑈ @lukestein.com · 08/12/2024

Excited, grateful, and appreciative to receive news yesterday our work “Measuring and Mitigating Racial Disparities in LLM Mortgage Underwriting” was recognized as the Best Paper at the (fantastic!) New Zealand Finance Meeting acfr.aut.ac.nz/conferences-...

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⑆Luke Stein⑈ @lukestein.com · 08/12/2024

Somehow, just asking LLM to be unbiased • Eliminates approval recommendation gap (on average and across different credit scores) • Reduces average racial interest rate gap by about 60% (from 35bp to 14), with even larger effects for lower-credit-score Black applicants 8/

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⑆Luke Stein⑈ @lukestein.com · 08/12/2024

We find anti-Black bias in mortgage underwriting recommendations from a number of LLMs Black borrowers with low credit scores suffer the most 6/

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⑆Luke Stein⑈ @lukestein.com · 08/12/2024

LLMs recommend denying more loans and charging higher interest rates to Black applicants They would, on average, need credit scores ~120 points higher than white applicants to receive the same approval rate; ~30 higher to get same interest rate 4/

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⑆Luke Stein⑈ @lukestein.com · 08/12/2024

I.e., ChatGPT (we also assess other models) • Claims it’s unbiased… • …but it 𝗶𝘀 biased against Black applicants. Particularly at low credit scores. (We also have this for other risk measures.) • We can partly close the racial gap just by asking for unbiased responses. 3/

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⑆Luke Stein⑈ @lukestein.com · 08/12/2024

LLMs recommend denying more loans and charging higher interest rates to Black applicants Especially at low credit scores/riskier loans Simple prompt engineering can help mitigate gaps

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⑆Luke Stein⑈ @lukestein.com · 08/12/2024

WP thread: “Measuring and Mitigating Racial Bias in LLM Mortgage Underwriting” with Don Bowen, McKay Price, and Ke Yang Our audit study asks AI to assess simple mortgage applications (real HMDA data w/ randomized race and credit scores) 🦶🦶🏼🦶🏿 Download lukeste.in/llmmortgage 1/

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⑆Luke Stein⑈ @lukestein.com · 06/12/2024

It's in a slightly different vein, but @johnjhorton.bsky.social's watercolor-painting doctors thread is the one that really sticks in my mind

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⑆Luke Stein⑈ @lukestein.com · 02/12/2024

And then, right out of the blue, Ferrante drops a metrics gem

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⑆Luke Stein⑈ @lukestein.com · 27/11/2024

I mean, www.home-assistant.io/integrations...

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⑆Luke Stein⑈ @lukestein.com · 26/11/2024

When your appendix has 68 (underpowered) robustness tests

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⑆Luke Stein⑈ @lukestein.com · 25/11/2024

Sunday (yesterday) morning… a one-miler for the kids and then a 5K for the kids-at-heart

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⑆Luke Stein⑈ @lukestein.com · 24/11/2024

5K with my friend, neighbor, and colleague Linghang Zeng (Also anyone wondering about my bib number shouldn’t rule out manipulation of the running variable)

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⑆Luke Stein⑈ @lukestein.com · 22/11/2024

Wild that dentist office “requires” a bunch of signatures on this electronic pad and has no ability to print or even pull up on screen a version with signature line of what they’re asking me to sign Clearly in the first person they’ve ever had say “sorry, I need to see what I’m signing”

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⑆Luke Stein⑈ @lukestein.com · 17/11/2024

Yeah, I’m trying to open that app less for a variety of reasons, but at least on iOS it aggressively shifts to the “for you” tab whenever the app goes out of focus. Just so user-hostile.

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⑆Luke Stein⑈ @lukestein.com · 17/11/2024

What the algo is showing me on the other place

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⑆Luke Stein⑈ @lukestein.com · 16/11/2024

I was surprised the piece/dataviz at the Crimson didn’t seem to make any point about scale. Like, there’s a real quant difference between eg Roxbury Latin where 1 in 55 go to Harvard vs. Brookline High where 1 in 550 do.

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⑆Luke Stein⑈ @lukestein.com · 14/11/2024

I value my musical friends group chat so much

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⑆Luke Stein⑈ @lukestein.com · 10/11/2024

Also, reply to the op announcement👇 if you might be interested in joining a metro west Boston group run next month bsky.app/profile/econ...

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⑆Luke Stein⑈ @lukestein.com · 09/11/2024

Totally normal discourse about my kindergartener nephew in the family photo stream

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⑆Luke Stein⑈ @lukestein.com · 08/11/2024

Yeah and I suspect the press will alas suddenly be talking about the S&P hitting an all-time high as it did the day after the election AND 50 OTHER TIMES IN THE LAST YEAR!

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⑆Luke Stein⑈ @lukestein.com · 06/11/2024

I think bsky still doesn’t have post notifications so I keep having to manually check whether Rajiv has posted new explainers of wt is going on with prediction markets