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  • Vertical mergers in the technology, media and telecom sector

    In June 2019, the OECD Competition Committee discussed how competition authorities can effectively use merger control to reduce the risk of competition harm posed by potentially problematic vertical mergers, without compromising the many efficiencies typically associated with vertical integration.

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  • Competition Open Day 2019: Vertical restraints in e-commerce

    The first panel at the inaugural OECD Competition Open Day in 2019 opened the conversation about vertical restrains in e-commerce to the wider competition community. Watch a video of the session here with panelists Pinar Akman, Paolo Buccirossi and Gunnar Kallfass.

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  • The welfare effects of vertical mergers

    In this video Professor Margaret Slade, Professor Emeritus at the Vancouver School of Economics at the University of British Columbia offers her insights into the empirical evidence on the welfare effects of vertical mergers.

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Mergers: An integral part of the competition landscape to be closely monitored

Almost all systems of competition law provide for control of mergers, to prevent companies from joining together to eliminate competition between them.

A merger could be a complete union of two or more companies, a more one-sided takeover or the transfer of parts of one firm to another.

Deciding whether a merger will harm competition can require sophisticated economic analysis of markets and the effects of the transaction.  Yet this sophisticated analysis must in most jurisdictions be carried out to strict deadlines so as to protect the procedural rights of all affected parties.

Why do competition authorities analyse mergers?

Most mergers are beneficial to competition, or at least do no harm to it, so competition authorities typically conduct a quick screening exercise to identify the exceptions.  In, mergers between competitors can result in very large costs to consumers and to the economy more generally, so it is essential that authorities have the power and skills to investigate effectively and to remedy any potential problems they find (including by blocking the merger).

Mergers between companies that do not directly compete (such as a ‘vertical’ merger between a supplier and its customer) rarely raise competition concerns; but when they do, they require very sophisticated economic analysis to assess whether the effects are anti-competitive or efficiency-enhancing.



Debating merger control at the OECD

The OECD provides competition agencies with opportunities to debate the latest developments in merger control between themselves, as well as with international experts and the business community.  These debates cover the whole process from the initial notification of a merger, to assessment of the determination of remedies and finally ex post evaluation of the results.  The OECD has been closely involved in the development of common principles for the standard of review of mergers.  This extends to principles for co-operation between competition authorities when assessing international mergers, an area in which the OECD is currently focusing its efforts.



List of all roundtables on mergers

Latest roundtables on mergers

Common ownership by institutional investors and its impact on competition, 2017

Co-operation between Competition Agencies and Regulators in the Financial Sector: 10 years on from the Financial Crisis, 2017

Safe harbours and legal presumptions in competition law, 2017

Multi-sided markets: Rethinking the Use of Traditional Antitrust Enforcement Tools, 2017

Geographic market definition across national borders, 2016

Agency decision-making in merger cases: Prohibition and conditional clearances, 2016

Big data: Bringing competition policy to the digital era, 2016

Public interest considerations in merger control, 2016

Jurisdictional nexus in merger control regimes, 2016 

Oligopoly markets, 2015

Remedies in cross-border merger cases, 2013

Provisions in co-operation agreements on competition, 2014

Enhanced Enforcement Co-operation, 2014

Investigations of Consummated and Non-notifiable Mergers, 2014

Definition of Transaction for the Purpose of Merger Control Review, 2013

Role and Measurement of Quality in Competition Analysis, 2013


OECD Recommendation on Merger Review 2005

Country experiences with the OECD Recommendation on Merger Review


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