Welcome readers old and new to this week’s edition of the Best of Econtwitter newsletter. Please submit suggestions — very much including your own work! — over email or on Twitter @just_economics.
Idiosyncratic favorites
Misha Teplitskiy | Science of Science@MishaTeplitskiy
**How does GenAI affect grades in college? It can help learn, but it can also substitute for learning ("substitution hypothesis"). And how do students *experience* courses that GenAI can easily ace?**
We spent year+ trying to answer these questions, using some of the best data:
3:47 PM · Jul 24, 2026 · 29.4K Views
7 Replies · 5 Reposts · 31 Likes
Misha Teplitskiy | Science of Science@MishaTeplitskiy
The money shot.
Right panel are the diff in diff estimates under various assumptions about COVID.
Shaded area is the COVID period (though its end point is subjective)
arxiv.org/abs/2607.21534
3:47 PM · Jul 24, 2026 · 548 Views
1 Reply · 5 Likes
Kirill Borusyak@borusyak
Planning an RCT to learn about spillover effects?
@instrumenthull, @_evan_munro and I have new toys for you 🧵
Our new paper, "Robust Signal Maximization in Spillover Experiments", proposes an experimental design with large and robust power gains
arxiv.org/abs/2607.18601
1:33 PM · Jul 22, 2026 · 24.2K Views
3 Replies · 40 Reposts · 146 Likes
More paper summaries
Fernando Leibovici@LeiboviciF
🚢How vulnerable is global shipping to disruptions?
We study this question with @SimonFuchs4 and @WoanFoongWong in a new paper we presented last week at the International Trade and Investment (ITI) program of the @nberpubs's Summer Institute.
We develop a theory to
4:37 PM · Jul 21, 2026 · 2.39K Views
1 Reply · 9 Reposts · 31 Likes
Sergio Ocampo Díaz@socampdi
Can wealth taxes make capital markets more efficient❓
Realization-based capital-gains taxes can lock investors into low-return assets
We show a properly designed wealth tax unlocks capital
New paper w/Guttorm Schjelderup & @ZoutmanFloris from @NHHnor
🔗ssrn.com/abstract=71254… https://t.co/DxAjCdj1VL
11:29 AM · Jul 22, 2026 · 5.17K Views
3 Replies · 13 Reposts · 34 Likes
Brian Albrecht@BrianCAlbrecht
Consumers benefit from the waterbed effect.
You see it across different models of downstream competition. The old comment showed Inderst/Valletti's Hotelling.
This now shows it in Bertrand and Cournot, the three canonical models.
The general logic is simple 🧵
Brian Albrecht @BrianCAlbrecht
There's a famous paper in antitrust that is often cited as theoretical justifcation for taking the waterbed seriously.
The problem?
The waterbed never causes consumer harm in their model. https://t.co/7qUGVi6dwH
4:53 PM · Jul 24, 2026 · 11.3K Views
3 Replies · 8 Reposts · 28 Likes
Daniel P. Gross@daniel_p_gross
Our study of the Mansfield Amendment era of the 1970s, when the US Dept of Defense went from being a leading patron of university research to a much diminished one.
Takeaway, in one line: science, tech, and trainees in related fields declined, w long lasting impacts, including
NBER @nberpubs
Large cuts in US military university research funding in the 1970s drove lasting declines in scientists, PhDs, research output, and leadership in formerly defense-driven fields, from @daniel_p_gross, Bhaven N. Sampat, and @HansenZhang13 https://t.co/7kpG4DuJOU
5:18 PM · Jul 24, 2026 · 6.2K Views
1 Reply · 8 Reposts · 39 Likes
Aniruddha Ghosh@ani_econ
NEW WP: How much convexity do we really need? We introduce the notion of separate convexity, recover standard equivalences among continuity conditions, and generalize classic choice-theoretic open-graph and axiomatize representation results. #econtwitter
arxiv.org
On Continuity of Separately Convex Preferences and Correspondences
2:49 AM · Jul 23, 2026 · 1.58K Views
4 Reposts · 16 Likes
Martin Aragoneses@m_aragoneses
New paper on the nature of firm financing and growth we just presented at the NBER SI: conference.nber.org/conf_papers/f2…
Main result: Firms that borrow against existing assets early in life all end up in the same place, while firms that borrow earlier against future cash flows outperform
CEPR @cepr_org
New CEPR Discussion Paper - DP21767
The Nature of Firm Financing and Growth
Martin Aragoneses @m_aragoneses @INSEAD, Chris Hansman @EmoryEconomics, David Licher, Ramana Nanda @imperialcollege
https://t.co/51Kxi4y5CK
#CEPR_MG #CEPR_BCF #EconTwitter
12:22 PM · Jul 23, 2026 · 8.9K Views
1 Reply · 13 Reposts · 63 Likes
Alex Imas@alexolegimas
Very excited about the release of the ATLAS 1.0 white paper on AI use and the economy. The report is a broad collaboration between @Google & @GoogleDeepMind and covers how our AI is being used at scale.
The data set has 15 million de-identified interactions across a large
3:58 PM · Jul 23, 2026 · 48.5K Views
12 Replies · 70 Reposts · 273 Likes
Dan Ly@meddly
🚨New paper!🚨Who orders more testing: male physicians or female physicians? And what are the implications on patient outcomes? We examine these questions in the emergency department (ED) in @JAMAInternalMed.🧵1/
3:24 PM · Jul 20, 2026 · 5.04K Views
2 Replies · 5 Reposts · 14 Likes
