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Antoine Germain

@ant1germain

Assistant Professor @ Aix-Marseille School of Economics
Public, labor and welfare econ
antoine-germain.github.io Joined March 2011
1.5K Following 932 Followers 679 Posts

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Antoine Germain @ant1germain
🎉Honored to get this award from the European Association of Labour Economists for my former JMP.

Will update the paper soon! (now it's a binding promise)

And I hope to write many more papers showing how we can learn from historical and modern Belgian policies.
EALE @eale_sbe Oct 27
🏆 Congrats to Antoine Germain @ant1germain, winner of the EALE Young Labour Economist Award! His paper “Working time reductions and monopsony power” studies a 1910 nine-hour workday law in Belgian coal mines, combining convincing evidence and theory in a rich historical setting.
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Antoine Germain @ant1germain
The prediction of a 'compassionate conservative' is quite cool. Look at Belgian politics today where most parties have some form of wealth tax agenda, even on the center-right.
Yet there is no evidence of an increasing wealth inequality. Perharps perceiving one is enough
Ivan Werning Verified account @IvanWerning Oct 22
Today: California billionaire wealth tax prop 40.

Throwback: One of the papers I most enjoyed writing some 15 years ago (with Farhi and later Sleet, Yeltekin) was on Wealth taxation, nonlinear in a political economy with no commitment.

Let me explain what we did. I am not trying to take political sides really or advocate one thing or another. Enough of that and it is good to think of the economic logic in a basic way. As you see, the paper is more subtle.

The paper modeled a situation where you (e.g., voters, on average) want to do a "one time" wealth tax and promise never to do it again. The incentive to do so is increasing in the amount of wealth inequality. You have nonlinear taxes on wealth and income, so you have rich tools. However, you can't bind future politics or policies. Every now and then you reevaluate (vote).

Sounds familiar? Indeed, various basics of the real world tradeoffs are present.

Obvious: this is a time-consistency problem that leads to a 3rd best (third world?) outcome (not your standard optimal tax one, where you assume you can commit). Well known and studied. At its most basic, the temptation is confiscation (slogans: robin hood, socialism), but the expectation of this happening in future is of course a problem (slogans: capitalism, property rights).

Less obvious: what it is the best you can do today if you with your tax tools, given the situation and constraints. AGAIN: you are not allowed to say "I promise never to tax again". ALSO NOTE: the options are also not necessarily just a choice between taxing wealth now or never doing so. (As the debate on this oversimplify.) Logically: taxing never may just not be feasible/credible. Equally important: you may come up with a different more intermediate plan. Let's see...

Indeed, the model spits out something subtle. You actually declare a more moderate but progressive nonlinear tax on wealth that will be in place permanently. It is progressive with rising marginal tax rates: indeed, you subsidize savings for the poor (!) but tax the rich. In fact, you want to promise this tax today for the future, even if inequality is zero today. Why?

The credibility problem depends on the amount of wealth inequality. That is what affects the incentive to renege on promises and tax away wealth. The solution tries to deal with this by creating an environment that will lower or keep inequality in check, to avoid a temptation to fall into the time inconsistency revision. A progressive tax goes in that direction both mechanically and in terms of saving incentives.

(BTW, the fact that the tax comes out progressive is very clean and surprising, given that the optimal tax literature rarely obtains such results.)

Insight: By keeping inequality in check, it makes policy more credible, avoiding falling into a much worse 3rd best.

At the time, we called it a "compassionate conservative" solution: even if you want zero taxes, you compromise and do some progressive taxation, to avoid more radical taxes later. Metaphorically, the best way to deal with a tide is not by ignoring it, denying it or swimming frantically, you may have to float with it, adapt and swim moderately finding the right moves.

Links: (older ungated): crei.cat/wp-content/upl…
published: academic.oup.com/restud/article…

Footnote: We titled it capital taxation, but in reality it is more exactly about wealth taxation, e.g. it holds even in a world without capital, where people hold assets against each other etc.
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Antoine Germain @ant1germain
The whole point of no-tax theorems like Atkinson-Stiglitz and Diamond-Mirrlees is to give us the conditions under which there should be no tax.

There is no contradiction for an author to later argue that there should be a tax.
Matthew Lilley @MattGLilley Sep 22
Stiglitz (1976) v. Stiglitz (2026)

Atkinson–Stiglitz: redistribute through the income tax, not extra tax instruments.

California: "What about a tax on accumulated assets?"

Stiglitz: signed.

The theorem was unavailable for comment.
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Antoine Germain @ant1germain
are we at the optimal point of Aghion-Howitt the inverted U shape between competition and innovation?
Sebastien Bubeck Verified account @SebastienBubeck Sep 8
Some more technical points:

(a) We began working on the Millennium problems due to viral twitter rumors that Anthropic had resolved 2 Millenium problems. Our aim was to see whether our system was also capable of this impressive feat, especially given our excitement regarding the large recent capability increases of our internal model detailed in our blog post.

(b) We did not see any of their work until they released it publicly last night. One can in hindsight see that our proofs differ significantly and even the precise results proved are different in the Euler case (forced vs unforced). It is also worth noting that our team consisted largely of mathematicians, physicists and computer scientists with the deepest roots in academia and respect for the stature and integrity of the Millennium problems.

(c) Levent reached out unprompted to an OpenAI employee on Wednesday. Due to his numerous posts on Twitter (S^6, Jacobian, Hadamard…) which appear to represent Anthropic and use Anthropic internal models, we believed that their project was, at least in part, an Anthropic project. Additionally recent further tweets by Levent (“augustus mirabilis”) led us to believe that they had solved at least 1 Millennium problem and would likely release it soon.

(d) Regarding the level of human involvement on our end: although a group of people was involved in our efforts, we collectively had no research-level expertise in fluid dynamics and the Navier-Stokes problem, and therefore were unable to meaningfully contribute to the mathematical content. We involved several people in order to initially attempt multiple Millenium problems using a variety of multiagent techniques.
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