Tommaso Valletti

@tomvalletti.bsky.social

econ professor imperial college london

https://profiles.imperial.ac.uk/t.valletti

Tommaso M. Valletti is Professor of Economics at Imperial College Business School, and also Professor of Economics at the University of Rome Tor Vergata (Italy). He is a Fellow of CEPR. He is a Non-Executive Director to the board of the UK's Payment Systems Regulator. .. more

Economics 37%

Business 36%

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Reposted by Tommaso Valletti

Reposted by Roger A. Pielke, Vali Nasr, Trita Parsi , and 4 more Roger A. Pielke, Vali Nasr, Trita Parsi, C. Christine Fair, Tommaso Valletti, Alex Callinicos, Jože P. Damijan

Reposted by Tommaso Valletti

Reposted by Mouin Rabbani, Vali Nasr, Tommaso Valletti , and 4 more Mouin Rabbani, Vali Nasr, Tommaso Valletti, Jayati Ghosh, Andrea Roventini, Hugo Ñopo, Trudy Harpham

Reposted by Tommaso Valletti, Thom Brooks

Tommaso Valletti @tomvalletti.bsky.social · Aug 18

Once properly interpreted, econ theory overwhelmingly supports the ITOH.

👉 Without synergies/spillovers, mergers harm consumers.

So: weakening merger control in the name of innovation is misguided.
The economics is clear — the ITOH still stands.

📄 Article www.sciencedirect.com/science/arti...

The innovation theory of harm in merger control: Some clarifications

Recent literature has analyzed the unilateral effects of mergers on investment and innovation. This note explores the Innovation Theory of Harm from a…

www.sciencedirect.com

Tommaso Valletti @tomvalletti.bsky.social · Aug 18

My paper revisits the Innovation Theory of Harm (ITOH): mergers can reduce firms’ incentives to invest & innovate.

This theory has shaped major EU merger cases in telecoms & agro-chemicals.

What I find:

Tommaso Valletti @tomvalletti.bsky.social · Aug 18

🚨 New paper in Economics Letters!

Do mergers boost or harm innovation? The debate is heating up in EU & UK policy circles.

Some argue:
Relax merger control → more investment, productivity, competitiveness.
This view has influenced reports like Draghi’s & UK gov’t policy.
But is it right? 🤔

Reposted by Tommaso Valletti, Robert Metcalfe

Diane Coyle @dianecoyle1859.bsky.social · Jul 25

Call for papers, 4th UK Workshop on Digital Economics, London 28 November 2025: competitionpolicy.ac.uk/events/4th-w... This is always a great event

Centre for Competition Policy

High quality independent research into competition policy and regulation

competitionpolicy.ac.uk

Reposted by Nando Sigona, Ruth Mace, Tommaso Valletti

Reposted by Alex Coad, Tommaso Valletti, Robert Metcalfe

Brett Hollenbeck @bretthollenbeck.com · Jul 11

🚨Free data alert!! 🚨 Please share.

Large new dataset of Amazon product reviews, including full text and photos and product characteristics, with individual *reviews labeled as fake reviews*.

I believe this is the first publicly available data of this kind.

github.com/bretthollenb...

Tommaso Valletti @tomvalletti.bsky.social · Jul 1

Findings: Ex post actions against consummated mergers exist but do not have a good record of success.

Implications: postmerger policy ineffectiveness needs a more stringent ex ante policy in order to achieve the right balance.

Link to the pre-print:

papers.ssrn.com/sol3/papers....

Ciao

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Tommaso Valletti @tomvalletti.bsky.social · Jul 1

New paper just accepted in the Antitrust Law Journal written with John Kwoka.

We study the policy toward consummated mergers that prove to be anticompetitive, both in theoretical and empirical terms.

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