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Elliot Lipnowski @elliotlip.bsky.social · 10/03/2026

Rebrand “man cave” to “fortress of ballitude”

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Elliot Lipnowski @elliotlip.bsky.social · 06/12/2025

The remaining proofs would surely have been easier to write.

Elliot Lipnowski @elliotlip.bsky.social · 05/12/2025

It's equilibrium existence, so fitting that it's about as popular at the party as a theorist is.

Elliot Lipnowski @elliotlip.bsky.social · 05/12/2025

Did you work more on this after first posting? I think I tried it at the time (working on this paper was what prompted my question), and the flow chart it gave was way sparser than this one (which is pretty great though not complete).

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Elliot Lipnowski @elliotlip.bsky.social · 05/12/2025

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

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Reposted by Elliot Lipnowski

VSET Virtual Seminars in Economic Theory @vset.bsky.social · 14/11/2025

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

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Elliot Lipnowski @elliotlip.bsky.social · 30/09/2025

I’m sorry to learn your baby isn’t a theorist

Elliot Lipnowski @elliotlip.bsky.social · 28/09/2025

That is good too! But I meant noticing you can replace an argument with a bunch of derivative-taking and epsilon-counting to one where an application of Tarski or Krein-Milman does most of the work.

Elliot Lipnowski @elliotlip.bsky.social · 21/09/2025

#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)?

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Reposted by Elliot Lipnowski

NY Times Pitchbot @nytpitchbot.bsky.social · 18/09/2025

Jimmy Kimmel has learned his lesson. by Susan Collins

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Elliot Lipnowski @elliotlip.bsky.social · 17/09/2025

The same mathematical result, not the same result as the sex. Perverts.

Elliot Lipnowski @elliotlip.bsky.social · 17/09/2025

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

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Elliot Lipnowski @elliotlip.bsky.social · 13/09/2025

I think there’s still an opportunity for price discrimination since the thing you’re screening on is how much time people are happy to spend on consuming the same content. And extra steps take time—so it’s similar to coupon clipping as price discrimination.

Elliot Lipnowski @elliotlip.bsky.social · 13/09/2025

My reasoning: the marginal cost is negligible relative to revenue, so it's a demand question. I think charging more to listen double-speed is effective price discrimination, since I would guess the people that want the fast version are less price-elastic.

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Elliot Lipnowski @elliotlip.bsky.social · 13/09/2025

This could be an argument for fairness of the "=rp" answer.

Elliot Lipnowski @elliotlip.bsky.social · 13/09/2025

Your way of phrasing is way better: if I listen to a book at double speed, should Spotify want to charge me more (>rp), less (<rp), or the same (=rp) as if I listen at regular speed?

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Elliot Lipnowski @elliotlip.bsky.social · 12/09/2025

I think I disagree, but I’m curious about your reasoning.

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Elliot Lipnowski @elliotlip.bsky.social · 12/09/2025

Fun micro #econsky problem set question: If p is the price Spotify charges for unit-speed listening (replacing a budget with a price for simplicity) and r>1, should they price r-speed listening =rp, >rp, or <rp?

Elliot Lipnowski @elliotlip.bsky.social · 12/09/2025

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.

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Elliot Lipnowski @elliotlip.bsky.social · 06/09/2025

Wednesday Addams is fashionable af

Poorly Drawn Lines @poorlydrawnlines.bsky.social · 15/08/2025

Reposted by Elliot Lipnowski

Boat question.

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Reposted by Elliot Lipnowski

NY Times Pitchbot @nytpitchbot.bsky.social · 29/08/2025

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

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Elliot Lipnowski @elliotlip.bsky.social · 28/08/2025

I was under the impression these were called "siblings"

Elliot Lipnowski @elliotlip.bsky.social · 13/08/2025

A kind of mechanical approach modifies Hart and Schmeidler's program to check, for every product set B of action profiles, whether some strict CE has marginal supports B_i. Then A^S is the largest B that passes the test (or empty if nothing does). But there must be something more interpretable!

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Elliot Lipnowski @elliotlip.bsky.social · 13/08/2025

1) The set CE^S is convex. 2) There's a product set A^S of action profiles such that (i) CE^S is contained in Δ(A^S), and (ii) if CE^S is nonempty, then something in CE^S has support A^S. 3) The closure of CE^S is just the intersection of CE and Δ(A^S). So it all comes down to what A^S is.

Elliot Lipnowski @elliotlip.bsky.social · 13/08/2025

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.

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Elliot Lipnowski @elliotlip.bsky.social · 02/08/2025

Thank you! This is all super helpful.

Elliot Lipnowski @elliotlip.bsky.social · 01/08/2025

The set of textbooks not being a lattice, it could be that so such textbook exists.

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Elliot Lipnowski @elliotlip.bsky.social · 01/08/2025

Probably the ideal book would have Stone duality as an advanced chapter? But I don’t really know enough to know what I want. I suspect I want the least advanced book among those that (1) defines a distributive lattice, and (2) has the word “continuous” somewhere in it.

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Elliot Lipnowski @elliotlip.bsky.social · 01/08/2025

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?

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Elliot Lipnowski @elliotlip.bsky.social · 29/07/2025

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.]

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Elliot Lipnowski @elliotlip.bsky.social · 26/07/2025

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

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Elliot Lipnowski @elliotlip.bsky.social · 22/07/2025

It's nothing obscure—it's in Kallenberg. But I just saw for the first time today. - By orthogonal projection, an L2 RV x admits a conditional expectation T(x). - By Jensen or direct argument, T is (weakly) L1-contractive. - But L2 is dense in L1, so T extends to (bounded linear map on) L2.