The Digital Markets Act (DMA) is the EU’s flagship regulatory framework for the competition and market-power problem of Big Tech platforms. The European Commission describes it as one of the first tools to comprehensively regulate the gatekeeper power of the largest digital companies.

Disclaimer: I am not a lawyer, and this post is not legal advice. These are my personal reading notes on the EU Digital Markets Act — it’s for academic purposes only, and all mistakes are my own. Readers should consult the official legal text and, where necessary, a qualified lawyer for legal advice.

TL;DR:

The EU Digital Markets Act is an ex ante regulatory regime for large digital platforms that act as unavoidable gateways between businesses and users.

Traditional antitrust is ex post, case-specific, and usually requires proof of dominance, market definition, anticompetitive effects, or abuse. The DMA instead imposes predefined obligations on designated gatekeepers to prevent recurring structural problems before they harden.

The DMA targets structural sources of platform power—network effects, scale economies, data advantages, lock-in, vertical integration, and control over access points such as app stores, search, operating systems, browsers, messaging, cloud, and advertising. The goal is to keep digital markets contestable and fair:

  • Weak contestability: rivals cannot effectively challenge the gatekeeper because of entry barriers, data advantages, switching frictions, ranking control, ecosystem tying, or lack of interoperability.
  • Unfairness: the gatekeeper can impose unbalanced terms on business users or end users because it controls access to a critical digital channel.

The Act mainly designates a firm as gatekeepers on the following criteria:

  • It has a significant impact on the EU internal market.
  • It provides a core platform service that is an important gateway for business users to reach end users.
  • It has, or is expected soon to have, an entrenched and durable position.

Once designated, gatekeepers face conduct rules: they must comply to

  • limit cross-service data use without consent
  • allow business users to steer customers outside the platform,
  • no unreasonable tying, defaults, and ecosystem control: eg alternative payment and app-distribution channels
  • avoid self-preferencing, enable switching and interoperability
  • provide advertising transparency, and
  • report relevant digital acquisitions.

And more if I missed any. I think tho the most interesting thing is that Gatekeepers bear the primary burden of designing, documenting, and demonstrating compliance, while the Commission remains the external supervisor and enforcer. They must proactively:

  • design their services to comply with the DMA;
  • prepare and submit compliance reports;
  • explain the measures they have taken;
  • maintain an internal compliance function;
  • appoint compliance officers with sufficient independence and authority;
  • provide audited descriptions of consumer-profiling techniques.

Reference

Regulation (EU) 2022/1925 of the European Parliament and of the Council of 14 September 2022 on contestable and fair markets in the digital sector and amending Directives (EU) 2019/1937 and (EU) 2020/1828 (Digital Markets Act). Official Journal of the European Union L 265, 12.10.2022.