Florian Ederer

Great in-depth piece on the Texas v. BlackRock common ownership lawsuit
www.mlex.com/mlex/article...

Who is Maurice R. Greenberg?!?

Yes, absolutely. This is strictly about US national welfare.

More evidence of market / power concentration, cc @helenamalikova.bsky.social via @conjugateprior.org who recommends @florianederer.bsky.social as a follow.

From the funders' perspective, it's a lot easier to "cash in" via a sale, so how can governments encourage them to accept the risk of an IPO?

Congrats!

But what you also really need to make this work is that there is no retaliation by other countries and the tariff revenue is properly spent on reducing (distortionary) income taxes for domestic consumers.

The government collects tariff revenue equal to c+e, which is the tariff t times imports M₂=D₂-S₂.

The net effect on national welfare is e-(b+d), which can be positive if e is sufficiently large.

How large e is depends on how much market power the US has (Pᵂ goes to P*).

US demand falls from D₁ to D₂, US domestic supply rises from S₁ to S₂, and imports shrink from M₁ to M₂.

Consumers buy less at a higher price so their surplus falls by the area a+b+c+d. Domestic producers benefit from higher prices and gain a.

Without tariffs, the domestic price is at the world market level Pᵂ.

When a large country like the US imposes a tariff, the domestic price rises to P*+t (less than the full tariff t) because the world market price falls to P*. Part of the tariff falls on foreign producers.

How can tariffs improve welfare? Your country needs market power.

A quick explainer below 👇🏻

I'm so excited to see this paper coming out in RESTUD.

Fun facts about this paper:
1) My amazing co-author Bruno and I had never met in person until after we completed the first draft.
2) It's my first and only paper that was never rejected by a journal.
3) I can now claim to understand macro.

"Number of VC-backed start-ups that exited via an initial public offering (black) or an acquisition (gray) by year." IPOs are declining over time, Acquisitions are increasing over time.

I do not like this trend.

From "The Great Start-up Sellout and the Rise of Oligopoly" by @florianederer.bsky.social and Bruno Pellegrino.

florianederer.github.io/startups_P&P...

"Common ownership grew dramatically in the US economy from 1995 to 2021. It could raise producer profits at the expense of consumer surplus & lead to a substantial deadweight loss."

Recently accepted paper by @florianederer.bsky.social & Pellegrino:

www.restud.com/a-tale-of-tw...

#econsky
#REStud

YouTube video by CEPR & VideoVox Economics Updating Merger Control as an Economic Policy Tool for Europe?

I was thrilled to join Emanuele Tarantino, Susan Athey, Cristina Caffarra & others for CEPR’s webinar on “Updating Merger Control as an Economic Policy Tool for Europe?”

How can merger policy adapt to support innovation, growth & strategic autonomy?

📺: youtu.be/CO_IJhFczCk

Common ownership has risen globally since 2005—especially among large firms—driven by the broad, overlapping portfolios of the Big Three (BlackRock, Vanguard, and State Street) asset management firms, from Antón, @florianederer.bsky.social, Giné, and Ramirez-Chiang https://www.nber.org/papers/w33965

Happy 4th of July to you all! 🇺🇸🎹🎶🎆

All posts critical of Yale Law School are hereby suspended.

Common Ownership Around the World Founded in 1920, the NBER is a private, non-profit, non-partisan organization dedicated to conducting economic research and to disseminating research findings among academics, public policy makers, an...

If this short thread has piqued your interest, here is the full 92-page behemoth.

NBER Working Paper:
nber.org/papers/w33965

Ungated version:
florianederer.github.io/co_around_th...

Legal, institutional, and market factors matter. We find that common ownership is higher where investor protection is stronger and capital markets are more developed but lower when government-led ESG disclosure is mandatory.

(Who doesn't love some OG cross-country regressions?)

Common ownership is also most pronounced among the largest firms. In every region, common ownership is especially prevalent among top firms by market cap, those firms that matter most for market concentration and competition.

But it's increasingly also reaching smaller firms.

Common ownership is not just rising, it's concentrated among the largest asset managers.

The "Big Three" (BlackRock, Vanguard, State Street) hold broad and deep stakes in thousands of firms. This combination of spread and intensity is what powers most of the global rise.

However, the U.S. is a clear outlier. Common ownership levels in the U.S. are more than 3 times higher than in the next closest countries, driven largely by institutional investors like BlackRock and Vanguard.

But other countries are catching up.

Common ownership can mute competition, reshape corporate governance, and raise antitrust concerns. Understanding its global reach is key for regulators and researchers alike.

Yet almost all the data on common ownership that exists so far is limited to the U.S.

🚨New Working Paper🚨

"Common Ownership Around the World"📈🌍

We analyze common ownership in 49 countries from 2005 to 2019 and show that it is widespread and rising globally.

Alright, I've peaked. It's only downhill from here.

"But how is this economics?"
www.thepeakmagazine.com.sg/influence/it...

Like Great-Grandparent, Like Great-Grandchild? Multigenerational Mobility in American History Founded in 1920, the NBER is a private, non-profit, non-partisan organization dedicated to conducting economic research and to disseminating research findings among academics, public policy makers, an...

The past really sticks.

Even after 4 generations, your great-grandfather’s economic status still largely shapes your own.

👉 33% persistence across time for whites
👉 But racial inequality is the key driver

The American Dream? More inherited than we thought.
www.nber.org/papers/w33923

AI and Social Media: A Political Economy Perspective Founded in 1920, the NBER is a private, non-profit, non-partisan organization dedicated to conducting economic research and to disseminating research findings among academics, public policy makers, an...

AI + social media = polarization machine 🧠📱

Recommender systems trap users in echo chambers and ad-based platforms profit from partisan division.
www.nber.org/papers/w33892

As this note further explains, FFN (2025) show that KY (2019)'s estimator only works under a knife-edge symmetry condition.

With even small cross-asset spillovers, it gives biased and unstable results, explaining those puzzlingly low elasticities.
danielneuhann.com/files/ffn_es...

Koijen & Yogo's (2019) demand system approach transformed asset pricing by linking portfolio data to demand elasticities. But why are estimated elasticities so low (around 1) when classical models say they should be much higher?

Enter Fuchs, Fukuda & Neuhann (2025)