Discussion papers B05

Advertiser Competition and Gatekeeping in Ad Funded Media

731/2026, B03, B05, Martin Peitz, Anton Sobolev, Paul Wegener

Competition Through Recommendations

718/2025, B05, Robin Ng

Recommendation Power and Competition

715/2025, B03, B04, B05, Martin Peitz, Anton Sobolev

Aligning Competition Policy and Industrial Policy in the EU

710/2025, B05, Tomaso Duso, Martin Peitz

Moderating Content-Hosting Platforms

698/2025, B05, Robin Ng, Greg Taylor. First version: August 2025

Coping with Undesirable Effects of DMA Implementation: Google Search and the Ban on Self-Preferencing

692/2025, B05, Jens-Uwe Franck, Mauro Hartl

Implementing and Enforcing the EU’s Digital Gatekeeper Regulation: A German Perspective on the Role of National Authorities

673/2025, B05, Jens‐Uwe Franck

Damages Actions Against Digital Gatekeepers for Breaches of EU Antitrust Law and the DMA: A German Perspective

671/2025, B05, Jens-Uwe Franck

Organized Voters: Elections and Public Funding of Nonprofits

601/2024, B05, Camille Urvoy. Published in American Economic Review 115 (2025), 183-219

Germany’s New Competition Tool: Sector Inquiry with Remedies

598/2024, B05, Jens-Uwe Franck, Martin Peitz. Published in the Journal of European Competition Law & Practice 15 (2025), 515-525

Product Recommendations and Price Parity Clauses

595/2024, B03, B04, B05, Martin Peitz, Anton Sobolev. First version: September 2024

Ratings with Heterogeneous Preferences

594/2024, B05, Jonathan Lafky, Robin Ng

Free and Open-Source Software: Coordination and Competition

585/2024, B05, Robin Ng

The Economic Theory of Two-Sided Platforms

584/2024, B05, Martin Peitz

Early Life Conditions, Time Preferences, and Savings

583/2024, A03, B05, Effrosyni Adamopoulou, Mattia Colombo, Eleftheria Triviza

Feed for Good? On the Effects of Personalization Algorithms in Social Media Platforms

580/2024, B05, Miguel Risco, Manuel Lleonart-Anguix. First version: July 2024

EU Merger Control and Climate Action: The Struggle for the Proper Framework

576/2024, B05, Jens-Uwe Franck

Geopolitical Risks and Prudential Merger Control

568/2024, B03, B05, Massimo Motta, Volker Nocke, Martin Peitz. Published in Journal of European Competition Law & Practice 15 (2024), 341-348

Biased Recommendations and Differentially Informed Consumers

554/2024, B03, B04, B05, Martin Peitz, Anton Sobolev. Forthcoming in Economic Theory Bulletin

Hosting Media Bias: Evidence from the Universe of French Broadcasts, 2002-2020

537/2024, B05, Julia Cagé, Moritz Hengel, Nicolas Hervé, Camille Urvoy

Digital Attention Intermediaries

520/2024, B05, Martin Peitz. Published in Seoul Journal of Economics 37 (2024), 1-36

Harvesting Ratings

509/2024, B05, Johannes Johnen, Robin Ng. First version: February 2024, Second version: July 2024, Third version: September 2025

Governance and Regulation of Platforms

480/2023, B05, Martin Peitz. Published in Handbook of New Institutional Economics (2025), 565-593

Platform-Enabled Information Disclosure

468/2023, B04, B05, Jacopo Gambato, Martin Peitz. Published in International Journal of Industrial Organization 99 (2025), 103143

Ad Blocking, Whitelisting, and Advertiser Competition

448/2023, B03, B04, B05, Martin Peitz, Anton Sobolev, Paul Wegener

Denial of Interoperability and Future First-Party Entry

447/2023, B05, Massimo Motta, Martin Peitz. Forthcoming in International Journal of Industrial Organization

The Digital Markets Act and the Whack-A-Mole Challenge

439/2023, B05, Jens-Uwe Franck, Martin Peitz. Published in Common Market Law Review 61 (2024), 299-344

Management Liability for Companies' Antitrust Fines

429/2023, B05, Jens-Uwe Franck, Till Seyer. First version: May 2023

Asymmetric Platform Oligopoly

428/2023, B05, Martin Peitz, Susumu Sato. First version: May 2023. Second version: July 2023. Forthcoming in RAND Journal of Economics

How to Apply the Self-Preferencing Prohibition in the DMA

422/2023, B05, Martin Peitz. Published in Journal of European Competition Law & Practice 14 (2023), 310-315

Network Effects on Information Acquisition by DeGroot Updaters

420/2023, B05, Miguel Risco. First version: April 2023. Forthcoming in Economic Theory

Market Definition and Three 19A Designations Under German Antitrust Law: Alphabet, Meta, and Amazon

386/2023, B05, Jens-Uwe Franck, Martin Peitz. Published in Competition Policy International Antitrust Chronicle (2023)

Enforcing Fintech Competition: Some Reflections on Institutional Design

375/2022, B05, Jens-Uwe Franck

The Law and Economics of AI Liability

371/2022, B05, Miriam Buiten, Alexandre de Streel, Martin Peitz. Published in Computer Law & Security Review 45 (2023), 105794

Open Markets in the Era of Fintech and Big Tech: Lessons for the Institutional Design of Competition Policy

367/2022, B05, Jens-Uwe Franck

Market Power of Digital Platforms

365/2022, B05, Jens-Uwe Franck, Martin Peitz. Published in Oxford Review of Economic Policy 39 (2023), 34-46

Selective Exposure Reduces Voluntary Contributions: Experimental Evidence from the German Internet Panel

340/2022, B05, Federico Innocenti, Linnéa Marie Rohde

Inflated Recommendations

336/2022, B03, B04, B05, Martin Peitz, Anton Sobolev. First version: February 2022

Collusion Between Non-differentiated Two-Sided Platforms

331/2022, B05, Martin Peitz, Lily Samkharadze. First version: January 2022. Published in Economic Letters 215 (2022), 110506

The Directive on Unfair Trading Practices in the Agri-Food Supply Chain: Regulatory Ambitions and Legal Instruments

304/2021, B05, Jens-Uwe Franck. Published in Zeitschrift für Europäisches Privatrecht 29 (2021), 843-891

Can Media Pluralism Be Harmful to News Quality?

298/2021, B05, Federico Innocenti. First version: May 2021

Digital Platforms and the New 19a Tool in the German Competition Act

297/2021, B05, Jens-Uwe Franck, Martin Peitz. Published in Journal of European Competition Law & Practice, 12: 513-528, 2021

Partial Compatibility in Oligopoly

278/2021, B05, Federico Innocenti, Domenico Menicucci. Published in Journal of Economic Behavior and Organization, 188: 351-378, 2021

Eating Habits, Food Consumption, and Health: The Role of Early Life Experiences

276/2021, A03, B05, Effrosyni Adamopoulou, Elisabetta Olivieri, Eleftheria Triviza. First version March 2021. Published in European Economic Review 166 (2024), 104743

Market Definition in the Platform Economy

259/2021, B05, Jens-Uwe Franck, Martin Peitz. First version: January 2021. Published in Cambridge Yearbook of European Legal Studies 23 (2021), 91-127

Preparing for the Next Crisis: How to Secure the Supply of Essential Goods and Services

210/2020, B05, Natalia Fabra, Massimo Motta, Martin Peitz. Published as "Learning from electricity markets: How to design a resilience strategy" in Energy Policy, 168, 113116, 2022

Removal of Potential Competitors - A Blind Spot of Merger Policy?

208/2020, B05, Massimo Motta, Martin Peitz. Published in Competition Law and Policy Debate, 6: 19-25, 2020

The Tension Between Market Shares and Profit Under Platform Competition

204/2020, B05, Paul Belleflamme, Martin Peitz, Eric Toulemonde. First version: August 2020. Published in International Journal of Industrial Organization 81 (2022), 102807

What Is ‘Competition Law’? – Measuring EU Member States’ Leeway to Regulate Platform-to-Business Agreements

202/2020, B05, Jens-Uwe Franck, Nils Stock. Published in Yearbook of European Law 39 (2020), 320-386

The Economics of Decoupling

201/2020, B02, B05, Andre Speit, Paul Voss

Shareholder Votes on Sale

200/2020, B02, B05, Andre Speit, Paul Voss

Network Goods, Price Discrimination, and Two-Sided Platforms

188/2020, B05, Paul Belleflamme, Martin Peitz. First version: June 2020.

Which Role for State Aid and Merger Control During and After the COVID Crisis?

184/2020, B05, Chiara Fumagalli, Massimo Motta, Martin Peitz. Published in Journal of European Competition Law & Practice, 11: 294-301, 2020

State Aid Policies in Response to the COVID-19 Shock: Observations and Guiding Principles

179/2020, B05, Massimo Motta, Martin Peitz. Published in Intereconomics 55 (2020), 219-222

Germany’s ‘Lex Apple Pay’: Payment Services Regulation Overtakes Competition Enforcement

173/2020, B05, Jens-Uwe Franck, Dimitrios Linardatos. First version: May 2020. Published as "Competition Enforcement versus Regulation as Market-Opening Tools: An Application to Banking and Payment Systems" in Journal of Antitrust Enforcement 12 (2024), 148-188

Student Performance and Loss Aversion

150/2020, B05, Heiko Karle, Dirk Engelmann, Martin Peitz. Published in The Scandinavian Journal of Economics 124 (2022), 420-456

Big Tech Mergers

147/2020, B05, Massimo Motta, Martin Peitz. First version: January 2020. Published in Information Economics and Policy, 54: 100868 , 2021

Ad Clutter, Time Use, and Media Diversity

140/2019, B05, Simon P. Anderson, Martin Peitz. First version: December 2019. Published in American Economic Journal: Microeconomics 15 (2023), 227-270

The Competitive Impacts of Exclusivity and Price Transparency in Markets with Digital Platforms

137/2019, B05, Paul Belleflamme, Martin Peitz. Published as "Digital & Competition" in Concurrences (2020), 2-7

Bidding in Common-Value Auctions with an Uncertain Number of Competitors

136/2019, B04, B05, Stephan Lauermann, Andre Speit. Published in Econometrica 91 (2023), 493-527

Segmentation Versus Agglomeration: Competition Between Platforms with Competitive Sellers

101/2019, B05, Heiko Karle, Martin Peitz, Markus Reisinger. Published in Journal of Political Economy, 128: 2329-2374, 2020

Price Disclosure by Two-sided Platforms

099/2019, B05, Paul Belleflamme, Martin Peitz. Published in International Journal of Industrial Organization, 67, 2019

Optimal Non-Linear Pricing Scheme When Consumers Are Habit Forming

098/2019, B05, Eleftheria Triviza. First version: June 2019. Published as "Optimal Pricing Scheme for Addictive Goods" in RAND Journal of Economics 55 (2024), 603-626

Media See-Saws: Winners and Losers in Platform Markets

089/2019, B05, Simon P. Anderson, Martin Peitz. First version: May 2019. Published in Journal of Economic Theory, 186, 2020

Challenges for EU Merger Control

077/2019, B05, Massimo Motta, Martin Peitz. Published in Concurrences 2 (2019), 44-49

Ratings, Reviews, Recommendations and the Consumption of Cultural Goods

076/2019, B05, Paul Belleflamme, Martin Peitz. Published as "Ratings, Reviews, and Recommendations" in Handbook of Cultural Economics 3 (2020), 466-473

Rethinking Liability Rules for Online Hosting Platforms

074/2019, B05, Miriam Buiten, Alexandre de Streel, Martin Peitz. Published in International Journal of Law and Information Technology, 2020

Distorted Input Ratios in Vertical Relationships

060/2018, B05, Martin Peitz, Dongsoo Shin. Published in Scandinavian Journal of Economics, 122: 1480-1509, 2020

You Are Judged by the Company You Keep: Reputation Leverage in Vertically Related Markets

042/2018, B05, Jay Pil Choi, Martin Peitz. Published in International Journal of Industrial Organization, 61: 351-379, 2018

Striking a Balance of Power Between the Court of Justice and the EU Legislature: The Law on Competition Damages Actions as a Paradigm

037/2018, B05, Jens-Uwe Franck. Published in European Law Review, 43: 837-857, 2018

Managing Competition on a Two-Sided Platform

028/2018, B05, Paul Belleflamme, Martin Peitz. Published in Journal of Economics and Management Strategy, 28: 5-22, 2019

A Fresh Look at Zero-Rating

027/2018, B05, Jan Krämer, Martin Peitz. Published in Telecommunications Policy 42, 501-513

Consumer Search with and Without Tracking

021/2018, B05, Marcel Preuss. Published as "Search, Learning, and Tracking" in RAND Journal of Economics 54 (2023), 54-82

Toward a Coherent Policy on Cartel Damages

007/2018, B05, Jens-Uwe Franck, Martin Peitz. Published as "Cartel Effects and Component Makers’ Rights to Damages" in World Competition, 43: 209-240, 2020

Inside the Engine Room of Digital Platforms: Reviews, Ratings, and Recommendations

004/2018, B05, Paul Belleflamme, Martin Peitz. Published in J.J. Ganuza and G. Llobet (eds.), Economic Analysis of the Digital Revolution, Funcas Social and Economic Studies, 5: 215-254, 2018

Platform Competition: Who Benefits from Multihoming?

001/2018, B05, Paul Belleflamme, Martin Peitz. Published in International Journal of Industrial Organization, 64: 1-26, 2019