As markets evolve in complexity and scale, it becomes increasingly relevant to understand how the conduct of companies may influence competitive dynamics. The interconnected nature of economic activities means that business practices often have ripple effects, regardless of where they originate. In this context, effective competition increasingly relies on the ability of competition authorities to successfully intervene in situations where transactions or behaviour are distorting competition. To achieve effective enforcement, adopting remedies appears as an available tool for authorities for authorising mergers or as a way to close antitrust investigations. Remedies, if well-designed, can correct distortions to competition and deter future anti-competitive behaviour.1
Remedy design is, however, a complex task. It is case-specific, fact-intensive and should respond to clear objectives, including the overarching goals of competition laws in each jurisdiction. There are situations where the process can benefit from the ability of all relevant actors – competition authorities, businesses and other stakeholders – to engage in co-operative design of the remedies.
As the OECD Recommendation of the Council Concerning International Co-operation on Competition Investigations and Proceedings [OECD/LEGAL/0408] recognises, co-operation includes a broad range of practices. They may go “from informal discussions to more formal co-operation activities based on legal instruments at the national or international level”. These practices are employed by competition authorities or courts to ensure more efficient or effective reviews of anticompetitive practices or mergers, and may also include more general discussions related to competition policy and enforcement practices. This paper addresses all types of practices, acknowledging that each may pose distinct challenges for authorities and that, depending on the legal framework or specific circumstances, some may be more readily applicable than others.
Fostering collaboration, as this paper illustrates, can enable a better design of remedies that are implementable and achieve the intended outcomes. Moreover, involving different actors in their design can help understand alternatives, guarantee consistency and avoid conflicting actions that may overshadow effectiveness of the intervention. When transactions or conduct may impact competitive dynamics abroad, interactions with other competition authorities may be beneficial. For example, transactions or behaviour may raise competition concerns in multiple jurisdictions, and, therefore, must change to correct market distortions. In the context of competition enforcement, investigations may involve foreign conduct with domestic harm or even global conduct with effects spanning multiple jurisdictions. In both situations, co‑ordinating efforts to design remedies can improve enforcement effectiveness and prevent conflicting outcomes.
Remedies, while not used in a significant share of cases, are part of the regular activities of competition authorities. Per year, 3.2% of the mergers reviewed by competition authorities in the OECD CompStats database are approved with conditions. Simultaneously, each year, authorities terminate around one third of their abuse of dominance cases early with commitments (OECD, 2025[1]).
The need for co-operation in antitrust remedy design, and broader considerations for the process of defining them have been extensively debated at the OECD. The theoretical and practical values, as well as challenges of co-operation have also been understood for many years. Discussions around remedies include the roundtables: “Ex-post Assessment of Merger Remedies” (OECD, 2023[2]), “Remedies and Commitments in Abuse Cases” (OECD, 2022[3]), “Designing and Testing Effective Consumer-facing Remedies” (OECD, 2018[4]) and “Commitment Decisions in Antitrust Cases” (OECD, 2016[5]). Conversations have also touched upon cross-border issues, such as in 2024, when a roundtable on “Challenges and Sources of Divergence in Cross-border Merger Review” dealt with co-ordination between authorities in different areas of merger review, including remedies (OECD, 2024[6]), and the discussion on “Extraterritorial Reach of Competition Remedies” (OECD, 2017[7]).
Key principles governing remedy design have been consolidated in different OECD Recommendations. These include the following considerations on co-operation:
The OECD Recommendation of the Council Concerning International Co-operation on Competition Investigations and Proceedings [OECD/LEGAL/0408], adopted in 2014, recommends its Adherents to co-ordinate in “the design and implementation of remedies to address anticompetitive concerns identified by competition authorities in different Adherents”.2
The OECD Recommendation on Merger Review [OECD/LEGAL/0333], revised in 2025, recommends Adherents to “co-operate with other reviewing jurisdictions on remedy design and implementation in transnational mergers, so as to bolster their effectiveness while avoiding inconsistencies.” It further recommends Adherents to ensure that remedies are effective in light of applicable sectoral regulation, which in turn involves alignment with regulators and other relevant public stakeholders.
The OECD Recommendation on Transparency and Procedural Fairness in Competition Law and Enforcement [OECD/LEGAL/0465] stresses the need to ensure non-discriminatory, proportionate and consistent enforcement decisions in general, which applies to remedy decisions.
This paper focuses on the co-operative aspect of remedy design in merger and abuse cases and market investigations between competition authorities and other stakeholders, leaving aside broader, general issues that authorities face when designing remedies, as well as other areas of co-operation (e.g. co-operation for market definition). In this sense, it centres on situations where there is value from co-operation, omitting scenarios where evident divergences do not leave room for collaboration (although co-operation may be a way to understand them). The discussion includes all remedies where co-operation may be useful, touching upon remedies with extraterritorial reach, but without engaging into a discussion on the need to prove effects of a foreign conduct.3
The remainder of the paper is structured as follows. The second section sets the scene, presenting key definitions and principles of remedies. The third section presents the rationale for following a co-operative approach in remedy design. The fourth one goes through the architecture of remedy design, discussing mechanisms for engagement by type of stakeholders, and describing general obstacles that may arise and limit co-operation. The final section sets some conclusions.
The paper concludes that a co-operative approach to the design of remedies can guarantee timely and effective intervention. Engaging with parties, market participants, sector regulators and other relevant private or public actors can enhance the quality, feasibility and legitimacy of remedies. It shows different strategies that competition authorities can employ to facilitate co-operation in remedy design, acknowledging obstacles and challenges that ultimately determine how the collaboration between the different actors looks like in each case.