New paper! elliotlipnowski.com/wp-content/u...

Please join us on 20/Nov to hear Marina Halac (Yale) present "Agreeing to Implement", a joint work with Elliot Lipnowski and Doron Ravid. Panellists: Matteo Camboni and Sam Kapon. @elliotlip.bsky.social @doronravid.bsky.social @samkapon.bsky.social

#mathsky notation question. We feel totally comfortable with a decoration being a function (e.g., for a number x, let \bar{x}:=x^2). But what about a case/font/format change as a function (e.g., for a number x, let \mathbf{x} denote the constant function on [0,1] taking value x)?

Jimmy Kimmel has learned his lesson. by Susan Collins

Sex is great but have you tried replacing annoying quantitative bookkeeping arguments in a proof with qualitative arguments to get the same result??

Spotify account gives a budget of audiobook hours before needing to pay for more hours, but if you listen to a 10-hour book at double-speed (so 5 listening hours), it counts as 10 hours of your budget. So they price r-speed listening at exactly r times that of unit-speed listening.

Wednesday Addams is fashionable af

Boat question.

Schumer, Jeffries propose strongly-worded letter to counter RFK Jr.'s purge at the CDC.

Has anybody developed the theory of STRICT correlated equilibria of a finite game? #econsky #mathsky #ECsky #TCSsky I was playing around with it a bit, and here are some things that are easy to show about the set CE^S of strict correlated equilibrium distributions.

Seeking #mathsky book recs. I want a good textbook on basics of partial orders, lattices, and interactions of the same with basic topological notions like compactness. Does anybody have any book they like?

Fun, imprecise #mathsky question: Give a "nice" characterization of which subsets X of [0,1] are complete lattices. [Note, this is harder than the question of which X are complete *sub*lattices, and is much harder than the question of which X are lattices.]

Does anybody else here ever look for the ebook version because the hard copy is in another room?

A tiny #mathsky note on conditional expectations. I'd previously seen two standard existence results of different strengths: a) For square-integrable RVs (L2) via a super easy Hilbert space argument. b) For integral RVs (L1, a bigger class) via Radon-Nikodym—harder! But (a) can actually prove (b)!

Some recommended Independence Day #econsky reading

Everywhere I go, children gleefully throw things at me

Seeing how my kids fare in racing other kids at the playground is a VERY clear paternity test

During grad school, saw Bob Balaban three times in NYC, in three different neighborhoods. Once in a cafe, once on a bus, once on a subway.

LaTeX for gmail is no longer supported!!! 😭 Does anybody have any easy solutions to help me quickly write math in emails? #mathsky

Wanted: a program that will read me a mathematical paper in audio. Obviously best if it’s smart about (e.g.) when the symbol “X” should be pronounced “ex” and when it should be pronounced “big ex”. Has anyone in our brave new LLM world made this?

When you ask a computer scientist to tell you their model

Does anybody else sometimes try to reprove math results they've "known" for years just to feel something?

Fun, easy-but-a-bit-surprising #mathsky fact: there's no way to describe the complex-to-complex exponentiation function in terms of {0,1,+,x,<, and, or, not, exists} and the real-to-real exponential function.

Whether it’s Barack Obama wearing a tan suit to a press conference or Donald Trump running a multi-billion dollar crypto scam from the White House, both men tested the limits of presidential propriety.

The average American has three friends

Weird phenomenon when working in applied mathematical fields: just learning that an object has a NAME is already a nontrivial advance. The reason is that various objects happen to show up in our one-off papers, but then having a name can mean some math nerds have developed a general theory of it.

The dynamic moral hazard model is pretty cool

I'm on an email list for the Winnipeg Jewish summer camp I went to as a kid. It seems they just fired the camp director (who I remember being a camper when I was a counselor there—fuck I feel old) for *liking* a "Free Palestine" post on social media somewhere. This seems bananas to me.

WE ARE BACK next week!!! On Thursday, 24 April 2025, Alexander Wolitzky (MIT) will present "Marginal Reputation" (joint work with Daniel Luo). Our guest panellists: Jeff Ely and Elliot Lipnowski. Share the news! @jeffely.bsky.social @elliotlip.bsky.social

Underrated benefit of a standing desk: when I (regularly) spill an entire cup of water on my desk, the desk/floor/computer/papers get soaked but I stay happily dry

Is it just me, or is the shinier tracking/comment function in Overleaf way less usable than the one we had a couple months ago?

congratulations to all basketball teams. i’ll never know how you get the ball to bounce like that but whatever you’re doing, keep doing it

3yo needs to work on his “yes and” technique

here you go lemmatree.streamlit.app tried it on a random paper i found on arxiv econ.th ; seems to work fine

Somebody should make a tool that takes a mathematical paper and autogenerates a "lemma flowchart" that depicts which lemmas etc. are direct inputs to which other results.

Cancel-worthy take: we just bought a variety of Girl Scout cookies, and they’re really nothing special. Like, every flavor is clearly worse than an Oreo.

defining additive scoring rules

Game theory question: Has anybody studied equilibria with some sort of SEQUENTIAL rationality constraint in two-player undiscounted infinitely repeated games with one-sided incomplete information and perfect monitoring?

A little disheartening to realize TV characters I used to code as “big fat guy” when I was younger are now similarly proportioned to me

Is "Ain't No Mountain High Enough" a modal claim or merely a topographical observation?

Haven't read this yet, but looks interesting from the abstract spaces-cdn.owlstown.com/blobs/xswqjf...

My hero of an American-working-in-the-UK economic theorist being quoted as a character witness in the Canadian federal election was not on my bingo card

A very old Soviet joke, from an especially dark time: Foxes are fleeing the USSR in droves. Q: Why are you running away? Fox: The Soviets passed a new law that they’re going to arrest all camels. Q: But you’re foxes! Fox: Yeah, why don’t *you* try proving to the NKVD that you’re not a camel.

Notation idea for game theory. - It's convenient to use notation u_i(a_i, a_{-i}) for the profile with i using a_i and others using a_{-i}. - It's convenient to order players and let a=(a_1,...,a_n). - These conventions can conflict: e.g. in a symmetric game, which payoff is u_2(x,y) talking about?

Gonna rename my proof appendix "Choreography and Merriment"

A word of #mathsky advice: if you used duality an even number of times, you probably didn't need to use duality.

This seems like a cool #econsky paper

I just tried to read 3yo a book. He proclaimed “I’m too hot for this book” and walked away, and honestly I can relate.

Key & Peele's baby Forest Whitaker sketch is one of the more honest portrayals out there of the parenting experience