
Professor @EHESS_fr & @TSEinfoPast Président Association Française d'Economie des Transports Conference Director of the World Conference on Transport Research
Joined March 2010
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Marc Ivaldi retweeted
I have argued for the introduction of a specific defense tax to finance at least some fraction of the additional European defense effort, the rest being financed by debt.
There are two reasons for pushing such a tax. The first is economic. As the defense effort will, I am afraid, last a long time, it will eventually have to be financed by taxes. Best to start today. The second is political and, in my mind, more important. I think it essential to send the signal that defending Europe is not free. (To be clear and avoid the usual reaction to higher taxes: French deficits must be reduced, but one can reduce the deficit and still introduce a new tax if justified).
But I have just learned something interesting: The French constitution forbids the use of dedicated taxes. (Giscard d’Estaing cheated and introduce a “taxe secheresse” in 1976). And, indeed, the public finance textbook tells us that such dedicated taxes are a bad economic idea.
I wonder whether we should not revisit this stance. If people know where their money is going, they may be more open to contribute.
I made the same argument, with Jean Tirole, for rethinking inheritance taxes or, more generally, taxes on donations: If people knew that when they give one euro to their kids, they have to give 20 cents to a fund aimed at improving the education of poorer kids, they might feel differently about such taxes.
The argument goes beyond defense and donations. People worry about their taxes going into a big bucket and do not associate what they pay with what is done with it. In some cases, dedicated taxes may help.
Marc Ivaldi retweeted
A discussion with Larry Summers about the effects of tariffs and other US policies on the US and on Europe. shorturl.at/OqD0v
Larry’s place setter (15 minutes at the beginning) is a master class in showing the five fallacies underlying the US approach.
In mine (the next 15 minutes), I argue that, as a result of Trump and Putin, Europe has an Overton window, to react constructively and do things that it was unable to do in the past.
Toulouse School of Economics (TSE) is honored to host the 17th World Conference on Transport Research (WCTR) from 𝗝𝘂𝗹𝘆 𝟲–𝟭𝟬
linkedin.com/feed/update/urn…
Since the US tariff rate on imports was 2.5%, it should be 2.7%. Very far from the 20% imposed yesterday. Either it is a margin for bargaining or it is a misunderstanding of the VAT.
According to Trump administration's formula to compute reciprocal tarifs, the change in tariff rate applied to EU goods and services should be 8% since the goods and services imports of US from the EU are $924Billion and exports are $797Billion. 1/2
ustr.gov/issue-areas/recipro…
Happy to announce that the website of the next World Conference on Transport Research to be held in Toulouse on July 6-10, 2026 is online. You are invited to submit your scientific contributions on the submission platform at wctr2026.fr/
Marc Ivaldi retweeted
Friendly reminder how to model most tariffs economicforces.xyz/p/econ-10…
Canada/Mexico tariffs could slow data center construction:
"The tariff impact on electrical equipment for data centers is likely to be significant, said Ben Boucher, senior analyst for supply chain data and analytics at Wood MacKenzie."
bloomberg.com/news/articles/…
Marc Ivaldi retweeted
I'm in The Times quoted on supply shocks and egg prices.
Here is my fancy calibrated model of what happened
Le 7-1 du match #FRIR utilisé par l'équipe de 🇨🇵 de rugby confirme l'évolution du rugby vers plus de flexibilité dans les postes #FFR @LNRofficiel
Marc Ivaldi retweeted
Enough of the European gloom and doom. In the new world environment, Europe can and should have a major and exciting role to play. Namely, help create “coalitions of the willing”.
The argument, based on a new article with @pisaniferry, shorturl.at/j0Ewl
The Trump administration is systematically trampling on the traditional rules of international trade, and more generally, the rules of international behavior. Hampered by unanimity rules, multilateral institutions, be it the UN, the WTO, the WHO, etc, are increasingly unable to function.
Yet , many if not most countries are still willing to respect those rules, work to fight climate change, make sure that multinational companies pay their fair share, that tariffs, if used, are used for the right reasons and not to bully others, and so on.
The European Union, which has had to get 27 countries to agree to such rules, is in a unique position to lead and help the formation of coalitions of the willing, namely the set of countries willing to work to achieve specific goals, such as climate, taxation, trade, and looking for reliable partners, who will accept and then respect the rules .
By itself, the European Union is too small to make a large enough difference. Thus, it must enroll other non-EU countries. And if some EU countries do not want to participate, so be it. The proof of concept may be the Schengen agreement, which does not include all EU members but also includes some non EU members.
In general, it is essential to go far beyond Europe, work in particular with some of the Brics. Avoid "the West against the Rest". In that context, a major negotiation with China, recognizing the relevance of security considerations, the desire to protect certain industries, the rules determining the use of tariffs, would be a strong signal that the EU is not following the US blindly and that much of the world wants to continue to play by reasonable rules.
The linked note shows three areas where such coalitions look both essential and feasible, climate, trade and taxation. It discusses, in each case, what the rules could be both within the coalition and vis a vis countries outside, and how they can build on existing agreements.
There are a million technical issues to be solved in creating such coalitions. And obviously, Europe has other problems to solve, its low growth, its absence from some of the frontier technologies, how to respond to US tariffs, and so on. But we believe that, given today’s reality and geo political tensions, helping put place reasonable rules of international engagement is an exciting goal for Europe to set for itself.
Marc Ivaldi retweeted
Ça c’est ma 🇫🇷
Le record jusque là détenu par les Chinois est battu.
Une avancée sur la route vers la fusion nucléaire
#Fusion🔥| 1ère mondiale pour l'énergie de fusion !
👀Nouveau record obtenu dans le tokamak WEST, opéré sur le centre CEA de Cadarache : il a maintenu un plasma de fusion chaud de plusieurs dizaines de millions de degrés pendant 22 minutes avec 2,6 gigajoules d'énergie injectée.
Marc Ivaldi retweeted
At a minimum, the @deepseek_ai episode has exposed a dangerous degree of “groupthink” within the US AI industry, writes @DAcemogluMIT. bit.ly/4hzDkSu
That is to say, 0.004 percent of US Federal Budget. In 200 weeks, it would mean still less than 1% of the budget. 😜
🚨🇺🇸 DOGE CUTS QUICK: $45M SAVED BY DUMPING EMPTY FEDERAL BUILDINGS
Elon's efficiency team terminated 22 government leases in less than a week, moving agencies from ghost buildings to existing space.
The moves saved taxpayers $44.6M, up from $1.6M just days ago.
And they're just getting started - with 7,500 federal leases under review.
Source: @DOGE
Exemple d'inculture économique ou de mauvaise fois ou les 2. Et le pire ce sont tous les moutons qui applaudissent.
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Marc Ivaldi retweeted
The paper mentioned is our killer acquisition work with @marcivaldi and @selcukunekbas
Happy to read that @DAcemogluMIT is quoting our article forthcoming in ALJ @abaantitrust coauthored with @CompetitionProf and @selcukunekbas
This is a thread about remaking the tech sector.
Silicon Valley still claims the mantle of “disruption”, as if it is made up of competitive small companies rushing to innovate in order to edge into established industries. The truth is that Silicon Valley is now home to the largest corporations humanity has ever seen. At the beginning of the 20thcentury, when US society and lawmakers were alarmed about the growing power of “trusts” (large corporations), the two leading companies, Standard Oil and US Steel, had market capitalizations of around $1 billion, which in today’s currency would be worth about $32 billion. In comparison, Alphabet/Google’s and Amazon’s market valuations are hovering around $2.3 trillion, Apple’s is above $3.6 trillion, and Microsoft’s is close to $3 trillion. Today’s tech giants also have revenues that are more than 100 times those of early 20th century trusts, including Standard Oil and US Steel.
Tech boosters might argue that this is because of the innovativeness of these companies or an inevitable consequence of network economies, generating winner-take-all dynamics for companies that acquire the biggest clientele or the largest amount of data about users. The truth is more nuanced.
Tech companies have been innovative. Nevertheless, there is recent evidence suggesting that they have done so by employing a large fraction of the supply of innovators and scientists, and once an innovator starts working for these large corporations, they are less innovative than they used to be in smaller companies: ufukakcigit.com/s/Akcigit_Go…
Worse, tech giants have also grown their size partly by aggressively acquiring rivals: ftc.gov/system/files/documen…
Numerous acquisitions, like Facebook’s purchase of Instagram, did not just help tech giants grow rapidly. They may have also extinguished competition:
(see sciencedirect.com/science/ar…
or insights.som.yale.edu/insigh… also papers.ssrn.com/sol3/papers.…
for the contrary view).
My overall assessment from this evidence is that these companies have grown so much at least partly because of a failure of antitrust in the United States and Europe.
A tradition dating back to US Supreme Court Justice Louis Brandeis recognizes that a failure of antitrust will not just mean higher prices for consumers and bigger distortions. It would also pose a challenge to democracy, as these companies wield oversized political and social power. This is what we have to come to accept as normal today, with the tech sector becoming the second-largest vendor on lobbying in the United States (after pharma) and the values and viewpoints of Silicon Valley dominating every part of our social lives, including unfortunately journalism. (The data on lobbying expenditures come from Open Secrets, opensecrets.org/federal-lobb…).
Two key antitrust cases against Google’s monopoly in advertising on the two sides of the Atlantic could reshape the web and in the process kickstart a turnaround in antitrust philosophy and practice. (See npr.org/2024/10/09/nx-s1-514… ec.europa.eu/commission/pres…).
It is about time.
The background to the story is very well known. Digital ads dominate the web, and Google/Alphabet dominates digital ads (with Meta/Facebook being a distant second). The question is whether this state of affairs reflects Google’s amazing innovativeness in AdTech (the marketplace for digital advertising) or whether it also reflects the company’s monopolistic abuses. Lawmakers on both sides of the Atlantic are converging to the latter interpretation and are accusing Google of abusing its market power to generate monopoly profits and harming consumers, publishers and competition as a result.
US judge Amit P. Mehta ruledin August that Google had illegally monopolized the search engine market, among other things, by paying billions to be the default search engine on various platforms. After years of tech giants consolidating their hold over key markets, this could be a first step towards limiting this growth or even a prelude to a series of breakups.
True, the incoming Trump administration has promised to be much more friendly to various parts of the tech eco-system, and especially to artificial intelligence (AI) and crypto currency. Nevertheless, there is no love lost for Big Tech among some Trumpers. VP-in-waiting JD Vance, for example, recently praisedthe current head of the FTC, Lina Kahn, who is partly responsible for reenergizing anti-trust in the United States: fortune.com/2024/08/11/jd-va…
Next will be Europe’s turn. EU moved early against Big Tech, fining them for competition breaches and passing the Digital Markets Act and Digital Services Act. Yet the tech sector is as consolidated as ever and European consumers are still dependent on these mega platforms. EU could take a more decisive step towards ending the dominance of these tech companies with the Google AdTech case.
The root problem is Google’s overwhelming dominance of the entire AdTech ecosystem, which enables the company to act simultaneously as buyer, seller, and market-maker in an industry worth over $800 billion today and projected to grow to $2.5 trillion in the next several years: fortunebusinessinsights.com/…
Google’s control over the entire market leaves advertisers and publishers with little choice but to accept its terms.
This dynamic has been ruinous for many industries, including journalism. Independent publishers are a cornerstone of any democratic marketplace but can no longer survive squeezed by Google. In 2023, Google accrued 237 billion dollars from its AdTech monopoly, while the revenues of independent publishers and newspapers have declined. As a result, we have a new phenomenon: news deserts, which are areas where communities lack access to credible local news sources, once again damaging democracy and civic citizenship: cmpf.eui.eu/news-deserts-on-…
Big Tech defenders have historically claimed that breaking up these companies will harm consumers, slow innovation, and lead to economic stagnation. But monopolies are typically bad for innovation. If the AT&T monopoly wasn’t broken up in 1982, the digital and then the subsequent Internet revolutions may not have taken place. Why should the dominance of today’s Big Tech be any different?
Breaking up tech giants wouldn’t by itself be sufficient for a competitive marketplace in new technologies. In the US, bipartisan draft legislation proposes structural firewalls to prevent companies from operating on both sides of the AdTech market. Portions of the Digital Markets Act mandates ad transparency. If adopted on both sides of the Atlantic, these measures could help but are not sufficient.
I have argued repeatedly that the key challenge for today is to innovate in new technologies that provide better information and services to consumers and create new tasks and productivity-enhancing for workers: amazon.com/Power-Progress-Th…
Yet, such technologies are unlikely to be forthcoming rapidly when digital ads are the only game in town and most of the revenues online are from digital advertisements. This isn’t just because of the social negatives of massive data collection and the attention economy undergirding huge digital ad revenues, which are now well understood. It is also because the current structure is anti-competitive.
New companies experimenting with new technologies and business models are at a disadvantage relative to big platforms when they can only raise revenues by monetizing data via digital ads, because they have less data than established incumbents. Worse, as unknown quantities, they cannot develop new business models based on subscription fees or sales of new services when leading platforms are making money using digital ads.
One way of breaking this cycle is to impose a sizable digital ad tax in order to increase competition in the online economy, as Simon Johnson and I have argued. We proposed a tax of 50% for all ad revenues above $500 million a year, which EU can unilaterally impose, changing the whole digital game at one fell swoop: shapingwork.mit.edu/research…
Other reforms are also necessary. The future of the Internet and AI is entangled with creating a fair data economy, as a new report under the auspices of the Project Liberty Institute argues (to which I also contributed): projectliberty.io/news/proje…
To make such an aspiration a reality, we need new laws that simultaneously protect the privacy of individuals and lay the foundations for more inclusive markets, in which individuals and data collectives (or data unions) can control data, so that large platforms and AI companies cannot expropriate people’s information and the fruits of their labor.
I believe that this shouldn’t be bad for tech companies. The right architecture of data markets would ultimately help the tech sector by encouraging people to invest in and produce higher-quality data, which are a key input for more useful AI tools and more valuable online services. But there would be a lot of opposition from many tech companies today against any attempt to protect people’s data and introduce property rights over data.
Here, too, Europe can play the leading role, not only disrupting the current oligopoly in the tech sector but also taking steps towards a new, more productive, more competitive and fairer data economy.














